From 9063d7e2615f4a7ab321de6b520e23d370e58816 Mon Sep 17 00:00:00 2001 From: Massimiliano Pellizzer Date: Thu, 15 Jan 2026 15:30:50 +0100 Subject: [PATCH 01/11] apparmor: validate DFA start states are in bounds in unpack_pdb Start states are read from untrusted data and used as indexes into the DFA state tables. The aa_dfa_next() function call in unpack_pdb() will access dfa->tables[YYTD_ID_BASE][start], and if the start state exceeds the number of states in the DFA, this results in an out-of-bound read. ================================================================== BUG: KASAN: slab-out-of-bounds in aa_dfa_next+0x2a1/0x360 Read of size 4 at addr ffff88811956fb90 by task su/1097 ... Reject policies with out-of-bounds start states during unpacking to prevent the issue. Fixes: ad5ff3db53c6 ("AppArmor: Add ability to load extended policy") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: Massimiliano Pellizzer Signed-off-by: John Johansen --- security/apparmor/policy_unpack.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 1769417a9962..ba5d40dbeb24 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -1010,7 +1010,17 @@ static int unpack_pdb(struct aa_ext *e, struct aa_policydb **policy, if (!aa_unpack_u32(e, &pdb->start[AA_CLASS_FILE], "dfa_start")) { /* default start state for xmatch and file dfa */ pdb->start[AA_CLASS_FILE] = DFA_START; - } /* setup class index */ + } + + size_t state_count = pdb->dfa->tables[YYTD_ID_BASE]->td_lolen; + + if (pdb->start[0] >= state_count || + pdb->start[AA_CLASS_FILE] >= state_count) { + *info = "invalid dfa start state"; + goto fail; + } + + /* setup class index */ for (i = AA_CLASS_FILE + 1; i <= AA_CLASS_LAST; i++) { pdb->start[i] = aa_dfa_next(pdb->dfa, pdb->start[0], i); From e38c55d9f834e5b848bfed0f5c586aaf45acb825 Mon Sep 17 00:00:00 2001 From: Massimiliano Pellizzer Date: Tue, 20 Jan 2026 15:24:04 +0100 Subject: [PATCH 02/11] apparmor: fix memory leak in verify_header The function sets `*ns = NULL` on every call, leaking the namespace string allocated in previous iterations when multiple profiles are unpacked. This also breaks namespace consistency checking since *ns is always NULL when the comparison is made. Remove the incorrect assignment. The caller (aa_unpack) initializes *ns to NULL once before the loop, which is sufficient. Fixes: dd51c8485763 ("apparmor: provide base for multiple profiles to be replaced at once") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: Massimiliano Pellizzer Signed-off-by: John Johansen --- security/apparmor/policy_unpack.c | 1 - 1 file changed, 1 deletion(-) diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index ba5d40dbeb24..5d90ea55de82 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -1419,7 +1419,6 @@ static int verify_header(struct aa_ext *e, int required, const char **ns) { int error = -EPROTONOSUPPORT; const char *name = NULL; - *ns = NULL; /* get the interface version */ if (!aa_unpack_u32(e, &e->version, "version")) { From ab09264660f9de5d05d1ef4e225aa447c63a8747 Mon Sep 17 00:00:00 2001 From: Massimiliano Pellizzer Date: Tue, 13 Jan 2026 09:09:43 +0100 Subject: [PATCH 03/11] apparmor: replace recursive profile removal with iterative approach The profile removal code uses recursion when removing nested profiles, which can lead to kernel stack exhaustion and system crashes. Reproducer: $ pf='a'; for ((i=0; i<1024; i++)); do echo -e "profile $pf { \n }" | apparmor_parser -K -a; pf="$pf//x"; done $ echo -n a > /sys/kernel/security/apparmor/.remove Replace the recursive __aa_profile_list_release() approach with an iterative approach in __remove_profile(). The function repeatedly finds and removes leaf profiles until the entire subtree is removed, maintaining the same removal semantic without recursion. Fixes: c88d4c7b049e ("AppArmor: core policy routines") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: Massimiliano Pellizzer Signed-off-by: John Johansen --- security/apparmor/policy.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index 9108d74c6b46..566821852592 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -191,19 +191,43 @@ static void __list_remove_profile(struct aa_profile *profile) } /** - * __remove_profile - remove old profile, and children - * @profile: profile to be replaced (NOT NULL) + * __remove_profile - remove profile, and children + * @profile: profile to be removed (NOT NULL) * * Requires: namespace list lock be held, or list not be shared */ static void __remove_profile(struct aa_profile *profile) { + struct aa_profile *curr, *to_remove; + AA_BUG(!profile); AA_BUG(!profile->ns); AA_BUG(!mutex_is_locked(&profile->ns->lock)); /* release any children lists first */ - __aa_profile_list_release(&profile->base.profiles); + if (!list_empty(&profile->base.profiles)) { + curr = list_first_entry(&profile->base.profiles, struct aa_profile, base.list); + + while (curr != profile) { + + while (!list_empty(&curr->base.profiles)) + curr = list_first_entry(&curr->base.profiles, + struct aa_profile, base.list); + + to_remove = curr; + if (!list_is_last(&to_remove->base.list, + &aa_deref_parent(curr)->base.profiles)) + curr = list_next_entry(to_remove, base.list); + else + curr = aa_deref_parent(curr); + + /* released by free_profile */ + aa_label_remove(&to_remove->label); + __aafs_profile_rmdir(to_remove); + __list_remove_profile(to_remove); + } + } + /* released by free_profile */ aa_label_remove(&profile->label); __aafs_profile_rmdir(profile); From 306039414932c80f8420695a24d4fe10c84ccfb2 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Tue, 3 Mar 2026 11:08:02 -0800 Subject: [PATCH 04/11] apparmor: fix: limit the number of levels of policy namespaces Currently the number of policy namespaces is not bounded relying on the user namespace limit. However policy namespaces aren't strictly tied to user namespaces and it is possible to create them and nest them arbitrarily deep which can be used to exhaust system resource. Hard cap policy namespaces to the same depth as user namespaces. Fixes: c88d4c7b049e8 ("AppArmor: core policy routines") Reported-by: Qualys Security Advisory Reviewed-by: Ryan Lee Reviewed-by: Cengiz Can Signed-off-by: John Johansen --- security/apparmor/include/policy_ns.h | 2 ++ security/apparmor/policy_ns.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/security/apparmor/include/policy_ns.h b/security/apparmor/include/policy_ns.h index d646070fd966..cc6e84151812 100644 --- a/security/apparmor/include/policy_ns.h +++ b/security/apparmor/include/policy_ns.h @@ -18,6 +18,8 @@ #include "label.h" #include "policy.h" +/* Match max depth of user namespaces */ +#define MAX_NS_DEPTH 32 /* struct aa_ns_acct - accounting of profiles in namespace * @max_size: maximum space allowed for all profiles in namespace diff --git a/security/apparmor/policy_ns.c b/security/apparmor/policy_ns.c index 01b653a3609b..5a907a875d8f 100644 --- a/security/apparmor/policy_ns.c +++ b/security/apparmor/policy_ns.c @@ -223,6 +223,8 @@ static struct aa_ns *__aa_create_ns(struct aa_ns *parent, const char *name, AA_BUG(!name); AA_BUG(!mutex_is_locked(&parent->lock)); + if (parent->level > MAX_NS_DEPTH) + return ERR_PTR(-ENOSPC); ns = alloc_ns(parent->base.hname, name); if (!ns) return ERR_PTR(-ENOMEM); From 8756b68edae37ff546c02091989a4ceab3f20abd Mon Sep 17 00:00:00 2001 From: Massimiliano Pellizzer Date: Thu, 29 Jan 2026 17:08:25 +0100 Subject: [PATCH 05/11] apparmor: fix side-effect bug in match_char() macro usage The match_char() macro evaluates its character parameter multiple times when traversing differential encoding chains. When invoked with *str++, the string pointer advances on each iteration of the inner do-while loop, causing the DFA to check different characters at each iteration and therefore skip input characters. This results in out-of-bounds reads when the pointer advances past the input buffer boundary. [ 94.984676] ================================================================== [ 94.985301] BUG: KASAN: slab-out-of-bounds in aa_dfa_match+0x5ae/0x760 [ 94.985655] Read of size 1 at addr ffff888100342000 by task file/976 [ 94.986319] CPU: 7 UID: 1000 PID: 976 Comm: file Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy) [ 94.986322] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 94.986329] Call Trace: [ 94.986341] [ 94.986347] dump_stack_lvl+0x5e/0x80 [ 94.986374] print_report+0xc8/0x270 [ 94.986384] ? aa_dfa_match+0x5ae/0x760 [ 94.986388] kasan_report+0x118/0x150 [ 94.986401] ? aa_dfa_match+0x5ae/0x760 [ 94.986405] aa_dfa_match+0x5ae/0x760 [ 94.986408] __aa_path_perm+0x131/0x400 [ 94.986418] aa_path_perm+0x219/0x2f0 [ 94.986424] apparmor_file_open+0x345/0x570 [ 94.986431] security_file_open+0x5c/0x140 [ 94.986442] do_dentry_open+0x2f6/0x1120 [ 94.986450] vfs_open+0x38/0x2b0 [ 94.986453] ? may_open+0x1e2/0x2b0 [ 94.986466] path_openat+0x231b/0x2b30 [ 94.986469] ? __x64_sys_openat+0xf8/0x130 [ 94.986477] do_file_open+0x19d/0x360 [ 94.986487] do_sys_openat2+0x98/0x100 [ 94.986491] __x64_sys_openat+0xf8/0x130 [ 94.986499] do_syscall_64+0x8e/0x660 [ 94.986515] ? count_memcg_events+0x15f/0x3c0 [ 94.986526] ? srso_alias_return_thunk+0x5/0xfbef5 [ 94.986540] ? handle_mm_fault+0x1639/0x1ef0 [ 94.986551] ? vma_start_read+0xf0/0x320 [ 94.986558] ? srso_alias_return_thunk+0x5/0xfbef5 [ 94.986561] ? srso_alias_return_thunk+0x5/0xfbef5 [ 94.986563] ? fpregs_assert_state_consistent+0x50/0xe0 [ 94.986572] ? srso_alias_return_thunk+0x5/0xfbef5 [ 94.986574] ? arch_exit_to_user_mode_prepare+0x9/0xb0 [ 94.986587] ? srso_alias_return_thunk+0x5/0xfbef5 [ 94.986588] ? irqentry_exit+0x3c/0x590 [ 94.986595] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 94.986597] RIP: 0033:0x7fda4a79c3ea Fix by extracting the character value before invoking match_char, ensuring single evaluation per outer loop. Fixes: 074c1cd798cb ("apparmor: dfa move character match into a macro") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: Massimiliano Pellizzer Signed-off-by: John Johansen --- security/apparmor/match.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) diff --git a/security/apparmor/match.c b/security/apparmor/match.c index 8fa0a1494acd..30c46b119869 100644 --- a/security/apparmor/match.c +++ b/security/apparmor/match.c @@ -463,13 +463,18 @@ aa_state_t aa_dfa_match_len(struct aa_dfa *dfa, aa_state_t start, if (dfa->tables[YYTD_ID_EC]) { /* Equivalence class table defined */ u8 *equiv = EQUIV_TABLE(dfa); - for (; len; len--) - match_char(state, def, base, next, check, - equiv[(u8) *str++]); + for (; len; len--) { + u8 c = equiv[(u8) *str]; + + match_char(state, def, base, next, check, c); + str++; + } } else { /* default is direct to next state */ - for (; len; len--) - match_char(state, def, base, next, check, (u8) *str++); + for (; len; len--) { + match_char(state, def, base, next, check, (u8) *str); + str++; + } } return state; @@ -503,13 +508,18 @@ aa_state_t aa_dfa_match(struct aa_dfa *dfa, aa_state_t start, const char *str) /* Equivalence class table defined */ u8 *equiv = EQUIV_TABLE(dfa); /* default is direct to next state */ - while (*str) - match_char(state, def, base, next, check, - equiv[(u8) *str++]); + while (*str) { + u8 c = equiv[(u8) *str]; + + match_char(state, def, base, next, check, c); + str++; + } } else { /* default is direct to next state */ - while (*str) - match_char(state, def, base, next, check, (u8) *str++); + while (*str) { + match_char(state, def, base, next, check, (u8) *str); + str++; + } } return state; From d352873bbefa7eb39995239d0b44ccdf8aaa79a4 Mon Sep 17 00:00:00 2001 From: Massimiliano Pellizzer Date: Thu, 29 Jan 2026 16:51:11 +0100 Subject: [PATCH 06/11] apparmor: fix missing bounds check on DEFAULT table in verify_dfa() The verify_dfa() function only checks DEFAULT_TABLE bounds when the state is not differentially encoded. When the verification loop traverses the differential encoding chain, it reads k = DEFAULT_TABLE[j] and uses k as an array index without validation. A malformed DFA with DEFAULT_TABLE[j] >= state_count, therefore, causes both out-of-bounds reads and writes. [ 57.179855] ================================================================== [ 57.180549] BUG: KASAN: slab-out-of-bounds in verify_dfa+0x59a/0x660 [ 57.180904] Read of size 4 at addr ffff888100eadec4 by task su/993 [ 57.181554] CPU: 1 UID: 0 PID: 993 Comm: su Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy) [ 57.181558] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 57.181563] Call Trace: [ 57.181572] [ 57.181577] dump_stack_lvl+0x5e/0x80 [ 57.181596] print_report+0xc8/0x270 [ 57.181605] ? verify_dfa+0x59a/0x660 [ 57.181608] kasan_report+0x118/0x150 [ 57.181620] ? verify_dfa+0x59a/0x660 [ 57.181623] verify_dfa+0x59a/0x660 [ 57.181627] aa_dfa_unpack+0x1610/0x1740 [ 57.181629] ? __kmalloc_cache_noprof+0x1d0/0x470 [ 57.181640] unpack_pdb+0x86d/0x46b0 [ 57.181647] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181653] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181656] ? aa_unpack_nameX+0x1a8/0x300 [ 57.181659] aa_unpack+0x20b0/0x4c30 [ 57.181662] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181664] ? stack_depot_save_flags+0x33/0x700 [ 57.181681] ? kasan_save_track+0x4f/0x80 [ 57.181683] ? kasan_save_track+0x3e/0x80 [ 57.181686] ? __kasan_kmalloc+0x93/0xb0 [ 57.181688] ? __kvmalloc_node_noprof+0x44a/0x780 [ 57.181693] ? aa_simple_write_to_buffer+0x54/0x130 [ 57.181697] ? policy_update+0x154/0x330 [ 57.181704] aa_replace_profiles+0x15a/0x1dd0 [ 57.181707] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181710] ? __kvmalloc_node_noprof+0x44a/0x780 [ 57.181712] ? aa_loaddata_alloc+0x77/0x140 [ 57.181715] ? srso_alias_return_thunk+0x5/0xfbef5 [ 57.181717] ? _copy_from_user+0x2a/0x70 [ 57.181730] policy_update+0x17a/0x330 [ 57.181733] profile_replace+0x153/0x1a0 [ 57.181735] ? rw_verify_area+0x93/0x2d0 [ 57.181740] vfs_write+0x235/0xab0 [ 57.181745] ksys_write+0xb0/0x170 [ 57.181748] do_syscall_64+0x8e/0x660 [ 57.181762] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 57.181765] RIP: 0033:0x7f6192792eb2 Remove the MATCH_FLAG_DIFF_ENCODE condition to validate all DEFAULT_TABLE entries unconditionally. Fixes: 031dcc8f4e84 ("apparmor: dfa add support for state differential encoding") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: Massimiliano Pellizzer Signed-off-by: John Johansen --- security/apparmor/match.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/security/apparmor/match.c b/security/apparmor/match.c index 30c46b119869..2aad2cbed565 100644 --- a/security/apparmor/match.c +++ b/security/apparmor/match.c @@ -160,9 +160,10 @@ static int verify_dfa(struct aa_dfa *dfa) if (state_count == 0) goto out; for (i = 0; i < state_count; i++) { - if (!(BASE_TABLE(dfa)[i] & MATCH_FLAG_DIFF_ENCODE) && - (DEFAULT_TABLE(dfa)[i] >= state_count)) + if (DEFAULT_TABLE(dfa)[i] >= state_count) { + pr_err("AppArmor DFA default state out of bounds"); goto out; + } if (BASE_TABLE(dfa)[i] & MATCH_FLAGS_INVALID) { pr_err("AppArmor DFA state with invalid match flags"); goto out; From 5df0c44e8f5f619d3beb871207aded7c78414502 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Wed, 10 Sep 2025 06:22:17 -0700 Subject: [PATCH 07/11] apparmor: Fix double free of ns_name in aa_replace_profiles() if ns_name is NULL after 1071 error = aa_unpack(udata, &lh, &ns_name); and if ent->ns_name contains an ns_name in 1089 } else if (ent->ns_name) { then ns_name is assigned the ent->ns_name 1095 ns_name = ent->ns_name; however ent->ns_name is freed at 1262 aa_load_ent_free(ent); and then again when freeing ns_name at 1270 kfree(ns_name); Fix this by NULLing out ent->ns_name after it is transferred to ns_name Fixes: 145a0ef21c8e9 ("apparmor: fix blob compression when ns is forced on a policy load ") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: John Johansen --- security/apparmor/policy.c | 1 + 1 file changed, 1 insertion(+) diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index 566821852592..4476515d97b1 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -1166,6 +1166,7 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, goto fail; } ns_name = ent->ns_name; + ent->ns_name = NULL; } else count++; } From 6601e13e82841879406bf9f369032656f441a425 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Fri, 7 Nov 2025 08:36:04 -0800 Subject: [PATCH 08/11] apparmor: fix unprivileged local user can do privileged policy management An unprivileged local user can load, replace, and remove profiles by opening the apparmorfs interfaces, via a confused deputy attack, by passing the opened fd to a privileged process, and getting the privileged process to write to the interface. This does require a privileged target that can be manipulated to do the write for the unprivileged process, but once such access is achieved full policy management is possible and all the possible implications that implies: removing confinement, DoS of system or target applications by denying all execution, by-passing the unprivileged user namespace restriction, to exploiting kernel bugs for a local privilege escalation. The policy management interface can not have its permissions simply changed from 0666 to 0600 because non-root processes need to be able to load policy to different policy namespaces. Instead ensure the task writing the interface has privileges that are a subset of the task that opened the interface. This is already done via policy for confined processes, but unconfined can delegate access to the opened fd, by-passing the usual policy check. Fixes: b7fd2c0340eac ("apparmor: add per policy ns .load, .replace, .remove interface files") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: John Johansen --- security/apparmor/apparmorfs.c | 16 ++++++++------ security/apparmor/include/policy.h | 2 +- security/apparmor/policy.c | 34 +++++++++++++++++++++++++++++- 3 files changed, 43 insertions(+), 9 deletions(-) diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 2f84bd23edb6..81e57666a56e 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -417,7 +417,8 @@ static struct aa_loaddata *aa_simple_write_to_buffer(const char __user *userbuf, } static ssize_t policy_update(u32 mask, const char __user *buf, size_t size, - loff_t *pos, struct aa_ns *ns) + loff_t *pos, struct aa_ns *ns, + const struct cred *ocred) { struct aa_loaddata *data; struct aa_label *label; @@ -428,7 +429,7 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size, /* high level check about policy management - fine grained in * below after unpack */ - error = aa_may_manage_policy(current_cred(), label, ns, mask); + error = aa_may_manage_policy(current_cred(), label, ns, ocred, mask); if (error) goto end_section; @@ -449,7 +450,8 @@ static ssize_t profile_load(struct file *f, const char __user *buf, size_t size, loff_t *pos) { struct aa_ns *ns = aa_get_ns(f->f_inode->i_private); - int error = policy_update(AA_MAY_LOAD_POLICY, buf, size, pos, ns); + int error = policy_update(AA_MAY_LOAD_POLICY, buf, size, pos, ns, + f->f_cred); aa_put_ns(ns); @@ -467,7 +469,7 @@ static ssize_t profile_replace(struct file *f, const char __user *buf, { struct aa_ns *ns = aa_get_ns(f->f_inode->i_private); int error = policy_update(AA_MAY_LOAD_POLICY | AA_MAY_REPLACE_POLICY, - buf, size, pos, ns); + buf, size, pos, ns, f->f_cred); aa_put_ns(ns); return error; @@ -492,7 +494,7 @@ static ssize_t profile_remove(struct file *f, const char __user *buf, * below after unpack */ error = aa_may_manage_policy(current_cred(), label, ns, - AA_MAY_REMOVE_POLICY); + f->f_cred, AA_MAY_REMOVE_POLICY); if (error) goto out; @@ -1830,7 +1832,7 @@ static struct dentry *ns_mkdir_op(struct mnt_idmap *idmap, struct inode *dir, int error; label = begin_current_label_crit_section(); - error = aa_may_manage_policy(current_cred(), label, NULL, + error = aa_may_manage_policy(current_cred(), label, NULL, NULL, AA_MAY_LOAD_POLICY); end_current_label_crit_section(label); if (error) @@ -1880,7 +1882,7 @@ static int ns_rmdir_op(struct inode *dir, struct dentry *dentry) int error; label = begin_current_label_crit_section(); - error = aa_may_manage_policy(current_cred(), label, NULL, + error = aa_may_manage_policy(current_cred(), label, NULL, NULL, AA_MAY_LOAD_POLICY); end_current_label_crit_section(label); if (error) diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h index 5115ebae2661..fda9e75b8879 100644 --- a/security/apparmor/include/policy.h +++ b/security/apparmor/include/policy.h @@ -443,7 +443,7 @@ bool aa_policy_admin_capable(const struct cred *subj_cred, struct aa_label *label, struct aa_ns *ns); int aa_may_manage_policy(const struct cred *subj_cred, struct aa_label *label, struct aa_ns *ns, - u32 mask); + const struct cred *ocred, u32 mask); bool aa_current_policy_view_capable(struct aa_ns *ns); bool aa_current_policy_admin_capable(struct aa_ns *ns); diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index 4476515d97b1..e2bebf14a4d0 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -942,17 +942,44 @@ bool aa_current_policy_admin_capable(struct aa_ns *ns) return res; } +static bool is_subset_of_obj_privilege(const struct cred *cred, + struct aa_label *label, + const struct cred *ocred) +{ + if (cred == ocred) + return true; + + if (!aa_label_is_subset(label, cred_label(ocred))) + return false; + /* don't allow crossing userns for now */ + if (cred->user_ns != ocred->user_ns) + return false; + if (!cap_issubset(cred->cap_inheritable, ocred->cap_inheritable)) + return false; + if (!cap_issubset(cred->cap_permitted, ocred->cap_permitted)) + return false; + if (!cap_issubset(cred->cap_effective, ocred->cap_effective)) + return false; + if (!cap_issubset(cred->cap_bset, ocred->cap_bset)) + return false; + if (!cap_issubset(cred->cap_ambient, ocred->cap_ambient)) + return false; + return true; +} + + /** * aa_may_manage_policy - can the current task manage policy * @subj_cred: subjects cred * @label: label to check if it can manage policy * @ns: namespace being managed by @label (may be NULL if @label's ns) + * @ocred: object cred if request is coming from an open object * @mask: contains the policy manipulation operation being done * * Returns: 0 if the task is allowed to manipulate policy else error */ int aa_may_manage_policy(const struct cred *subj_cred, struct aa_label *label, - struct aa_ns *ns, u32 mask) + struct aa_ns *ns, const struct cred *ocred, u32 mask) { const char *op; @@ -968,6 +995,11 @@ int aa_may_manage_policy(const struct cred *subj_cred, struct aa_label *label, return audit_policy(label, op, NULL, NULL, "policy_locked", -EACCES); + if (ocred && !is_subset_of_obj_privilege(subj_cred, label, ocred)) + return audit_policy(label, op, NULL, NULL, + "not privileged for target profile", + -EACCES); + if (!aa_policy_admin_capable(subj_cred, label, ns)) return audit_policy(label, op, NULL, NULL, "not policy admin", -EACCES); From 39440b137546a3aa383cfdabc605fb73811b6093 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Fri, 17 Oct 2025 01:53:00 -0700 Subject: [PATCH 09/11] apparmor: fix differential encoding verification Differential encoding allows loops to be created if it is abused. To prevent this the unpack should verify that a diff-encode chain terminates. Unfortunately the differential encode verification had two bugs. 1. it conflated states that had gone through check and already been marked, with states that were currently being checked and marked. This means that loops in the current chain being verified are treated as a chain that has already been verified. 2. the order bailout on already checked states compared current chain check iterators j,k instead of using the outer loop iterator i. Meaning a step backwards in states in the current chain verification was being mistaken for moving to an already verified state. Move to a double mark scheme where already verified states get a different mark, than the current chain being kept. This enables us to also drop the backwards verification check that was the cause of the second error as any already verified state is already marked. Fixes: 031dcc8f4e84 ("apparmor: dfa add support for state differential encoding") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: John Johansen --- security/apparmor/include/match.h | 1 + security/apparmor/match.c | 23 +++++++++++++++++++---- 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/security/apparmor/include/match.h b/security/apparmor/include/match.h index 0dde8eda3d1a..7accb1c39849 100644 --- a/security/apparmor/include/match.h +++ b/security/apparmor/include/match.h @@ -185,6 +185,7 @@ static inline void aa_put_dfa(struct aa_dfa *dfa) #define MATCH_FLAG_DIFF_ENCODE 0x80000000 #define MARK_DIFF_ENCODE 0x40000000 #define MATCH_FLAG_OOB_TRANSITION 0x20000000 +#define MARK_DIFF_ENCODE_VERIFIED 0x10000000 #define MATCH_FLAGS_MASK 0xff000000 #define MATCH_FLAGS_VALID (MATCH_FLAG_DIFF_ENCODE | MATCH_FLAG_OOB_TRANSITION) #define MATCH_FLAGS_INVALID (MATCH_FLAGS_MASK & ~MATCH_FLAGS_VALID) diff --git a/security/apparmor/match.c b/security/apparmor/match.c index 2aad2cbed565..e9fac67e5178 100644 --- a/security/apparmor/match.c +++ b/security/apparmor/match.c @@ -202,16 +202,31 @@ static int verify_dfa(struct aa_dfa *dfa) size_t j, k; for (j = i; - (BASE_TABLE(dfa)[j] & MATCH_FLAG_DIFF_ENCODE) && - !(BASE_TABLE(dfa)[j] & MARK_DIFF_ENCODE); + ((BASE_TABLE(dfa)[j] & MATCH_FLAG_DIFF_ENCODE) && + !(BASE_TABLE(dfa)[j] & MARK_DIFF_ENCODE_VERIFIED)); j = k) { + if (BASE_TABLE(dfa)[j] & MARK_DIFF_ENCODE) + /* loop in current chain */ + goto out; k = DEFAULT_TABLE(dfa)[j]; if (j == k) + /* self loop */ goto out; - if (k < j) - break; /* already verified */ BASE_TABLE(dfa)[j] |= MARK_DIFF_ENCODE; } + /* move mark to verified */ + for (j = i; + (BASE_TABLE(dfa)[j] & MATCH_FLAG_DIFF_ENCODE); + j = k) { + k = DEFAULT_TABLE(dfa)[j]; + if (j < i) + /* jumps to state/chain that has been + * verified + */ + break; + BASE_TABLE(dfa)[j] &= ~MARK_DIFF_ENCODE; + BASE_TABLE(dfa)[j] |= MARK_DIFF_ENCODE_VERIFIED; + } } error = 0; From a0b7091c4de45a7325c8780e6934a894f92ac86b Mon Sep 17 00:00:00 2001 From: John Johansen Date: Tue, 24 Feb 2026 10:20:02 -0800 Subject: [PATCH 10/11] apparmor: fix race on rawdata dereference MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is a race condition that leads to a use-after-free situation: because the rawdata inodes are not refcounted, an attacker can start open()ing one of the rawdata files, and at the same time remove the last reference to this rawdata (by removing the corresponding profile, for example), which frees its struct aa_loaddata; as a result, when seq_rawdata_open() is reached, i_private is a dangling pointer and freed memory is accessed. The rawdata inodes weren't refcounted to avoid a circular refcount and were supposed to be held by the profile rawdata reference. However during profile removal there is a window where the vfs and profile destruction race, resulting in the use after free. Fix this by moving to a double refcount scheme. Where the profile refcount on rawdata is used to break the circular dependency. Allowing for freeing of the rawdata once all inode references to the rawdata are put. Fixes: 5d5182cae401 ("apparmor: move to per loaddata files, instead of replicating in profiles") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Tested-by: Salvatore Bonaccorso Signed-off-by: John Johansen --- security/apparmor/apparmorfs.c | 35 ++++++---- security/apparmor/include/policy_unpack.h | 79 ++++++++++++++--------- security/apparmor/policy.c | 12 ++-- security/apparmor/policy_unpack.c | 46 ++++++++----- 4 files changed, 104 insertions(+), 68 deletions(-) diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 81e57666a56e..7a6ca7c5500d 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -79,7 +79,7 @@ static void rawdata_f_data_free(struct rawdata_f_data *private) if (!private) return; - aa_put_loaddata(private->loaddata); + aa_put_i_loaddata(private->loaddata); kvfree(private); } @@ -409,7 +409,8 @@ static struct aa_loaddata *aa_simple_write_to_buffer(const char __user *userbuf, data->size = copy_size; if (copy_from_user(data->data, userbuf, copy_size)) { - aa_put_loaddata(data); + /* trigger free - don't need to put pcount */ + aa_put_i_loaddata(data); return ERR_PTR(-EFAULT); } @@ -437,7 +438,10 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size, error = PTR_ERR(data); if (!IS_ERR(data)) { error = aa_replace_profiles(ns, label, mask, data); - aa_put_loaddata(data); + /* put pcount, which will put count and free if no + * profiles referencing it. + */ + aa_put_profile_loaddata(data); } end_section: end_current_label_crit_section(label); @@ -508,7 +512,7 @@ static ssize_t profile_remove(struct file *f, const char __user *buf, if (!IS_ERR(data)) { data->data[size] = 0; error = aa_remove_profiles(ns, label, data->data, size); - aa_put_loaddata(data); + aa_put_profile_loaddata(data); } out: end_current_label_crit_section(label); @@ -1255,18 +1259,17 @@ static const struct file_operations seq_rawdata_ ##NAME ##_fops = { \ static int seq_rawdata_open(struct inode *inode, struct file *file, int (*show)(struct seq_file *, void *)) { - struct aa_loaddata *data = __aa_get_loaddata(inode->i_private); + struct aa_loaddata *data = aa_get_i_loaddata(inode->i_private); int error; if (!data) - /* lost race this ent is being reaped */ return -ENOENT; error = single_open(file, show, data); if (error) { AA_BUG(file->private_data && ((struct seq_file *)file->private_data)->private); - aa_put_loaddata(data); + aa_put_i_loaddata(data); } return error; @@ -1277,7 +1280,7 @@ static int seq_rawdata_release(struct inode *inode, struct file *file) struct seq_file *seq = (struct seq_file *) file->private_data; if (seq) - aa_put_loaddata(seq->private); + aa_put_i_loaddata(seq->private); return single_release(inode, file); } @@ -1389,9 +1392,8 @@ static int rawdata_open(struct inode *inode, struct file *file) if (!aa_current_policy_view_capable(NULL)) return -EACCES; - loaddata = __aa_get_loaddata(inode->i_private); + loaddata = aa_get_i_loaddata(inode->i_private); if (!loaddata) - /* lost race: this entry is being reaped */ return -ENOENT; private = rawdata_f_data_alloc(loaddata->size); @@ -1416,7 +1418,7 @@ static int rawdata_open(struct inode *inode, struct file *file) return error; fail_private_alloc: - aa_put_loaddata(loaddata); + aa_put_i_loaddata(loaddata); return error; } @@ -1433,9 +1435,9 @@ static void remove_rawdata_dents(struct aa_loaddata *rawdata) for (i = 0; i < AAFS_LOADDATA_NDENTS; i++) { if (!IS_ERR_OR_NULL(rawdata->dents[i])) { - /* no refcounts on i_private */ aafs_remove(rawdata->dents[i]); rawdata->dents[i] = NULL; + aa_put_i_loaddata(rawdata); } } } @@ -1474,18 +1476,21 @@ int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata) if (IS_ERR(dir)) /* ->name freed when rawdata freed */ return PTR_ERR(dir); + aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_DIR] = dir; dent = aafs_create_file("abi", S_IFREG | 0444, dir, rawdata, &seq_rawdata_abi_fops); if (IS_ERR(dent)) goto fail; + aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_ABI] = dent; dent = aafs_create_file("revision", S_IFREG | 0444, dir, rawdata, &seq_rawdata_revision_fops); if (IS_ERR(dent)) goto fail; + aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_REVISION] = dent; if (aa_g_hash_policy) { @@ -1493,6 +1498,7 @@ int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata) rawdata, &seq_rawdata_hash_fops); if (IS_ERR(dent)) goto fail; + aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_HASH] = dent; } @@ -1501,24 +1507,25 @@ int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata) &seq_rawdata_compressed_size_fops); if (IS_ERR(dent)) goto fail; + aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_COMPRESSED_SIZE] = dent; dent = aafs_create_file("raw_data", S_IFREG | 0444, dir, rawdata, &rawdata_fops); if (IS_ERR(dent)) goto fail; + aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_DATA] = dent; d_inode(dent)->i_size = rawdata->size; rawdata->ns = aa_get_ns(ns); list_add(&rawdata->list, &ns->rawdata_list); - /* no refcount on inode rawdata */ return 0; fail: remove_rawdata_dents(rawdata); - + aa_put_i_loaddata(rawdata); return PTR_ERR(dent); } #endif /* CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */ diff --git a/security/apparmor/include/policy_unpack.h b/security/apparmor/include/policy_unpack.h index a6f4611ee50c..4f800fbb805a 100644 --- a/security/apparmor/include/policy_unpack.h +++ b/security/apparmor/include/policy_unpack.h @@ -87,17 +87,29 @@ struct aa_ext { u32 version; }; -/* - * struct aa_loaddata - buffer of policy raw_data set +/* struct aa_loaddata - buffer of policy raw_data set + * @count: inode/filesystem refcount - use aa_get_i_loaddata() + * @pcount: profile refcount - use aa_get_profile_loaddata() + * @list: list the loaddata is on + * @work: used to do a delayed cleanup + * @dents: refs to dents created in aafs + * @ns: the namespace this loaddata was loaded into + * @name: + * @size: the size of the data that was loaded + * @compressed_size: the size of the data when it is compressed + * @revision: unique revision count that this data was loaded as + * @abi: the abi number the loaddata uses + * @hash: a hash of the loaddata, used to help dedup data * - * there is no loaddata ref for being on ns list, nor a ref from - * d_inode(@dentry) when grab a ref from these, @ns->lock must be held - * && __aa_get_loaddata() needs to be used, and the return value - * checked, if NULL the loaddata is already being reaped and should be - * considered dead. + * There is no loaddata ref for being on ns->rawdata_list, so + * @ns->lock must be held when walking the list. Dentries and + * inode opens hold refs on @count; profiles hold refs on @pcount. + * When the last @pcount drops, do_ploaddata_rmfs() removes the + * fs entries and drops the associated @count ref. */ struct aa_loaddata { struct kref count; + struct kref pcount; struct list_head list; struct work_struct work; struct dentry *dents[AAFS_LOADDATA_NDENTS]; @@ -118,53 +130,56 @@ struct aa_loaddata { int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, const char **ns); -/** - * __aa_get_loaddata - get a reference count to uncounted data reference - * @data: reference to get a count on - * - * Returns: pointer to reference OR NULL if race is lost and reference is - * being repeated. - * Requires: @data->ns->lock held, and the return code MUST be checked - * - * Use only from inode->i_private and @data->list found references - */ -static inline struct aa_loaddata * -__aa_get_loaddata(struct aa_loaddata *data) -{ - if (data && kref_get_unless_zero(&(data->count))) - return data; - - return NULL; -} - /** * aa_get_loaddata - get a reference count from a counted data reference * @data: reference to get a count on * - * Returns: point to reference + * Returns: pointer to reference * Requires: @data to have a valid reference count on it. It is a bug * if the race to reap can be encountered when it is used. */ static inline struct aa_loaddata * -aa_get_loaddata(struct aa_loaddata *data) +aa_get_i_loaddata(struct aa_loaddata *data) { - struct aa_loaddata *tmp = __aa_get_loaddata(data); - AA_BUG(data && !tmp); + if (data) + kref_get(&(data->count)); + return data; +} - return tmp; + +/** + * aa_get_profile_loaddata - get a profile reference count on loaddata + * @data: reference to get a count on + * + * Returns: pointer to reference + * Requires: @data to have a valid reference count on it. + */ +static inline struct aa_loaddata * +aa_get_profile_loaddata(struct aa_loaddata *data) +{ + if (data) + kref_get(&(data->pcount)); + return data; } void __aa_loaddata_update(struct aa_loaddata *data, long revision); bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r); void aa_loaddata_kref(struct kref *kref); +void aa_ploaddata_kref(struct kref *kref); struct aa_loaddata *aa_loaddata_alloc(size_t size); -static inline void aa_put_loaddata(struct aa_loaddata *data) +static inline void aa_put_i_loaddata(struct aa_loaddata *data) { if (data) kref_put(&data->count, aa_loaddata_kref); } +static inline void aa_put_profile_loaddata(struct aa_loaddata *data) +{ + if (data) + kref_put(&data->pcount, aa_ploaddata_kref); +} + #if IS_ENABLED(CONFIG_KUNIT) bool aa_inbounds(struct aa_ext *e, size_t size); size_t aa_unpack_u16_chunk(struct aa_ext *e, char **chunk); diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index e2bebf14a4d0..b6a5eb4021db 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -350,7 +350,7 @@ void aa_free_profile(struct aa_profile *profile) } kfree_sensitive(profile->hash); - aa_put_loaddata(profile->rawdata); + aa_put_profile_loaddata(profile->rawdata); aa_label_destroy(&profile->label); kfree_sensitive(profile); @@ -1171,7 +1171,7 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, LIST_HEAD(lh); op = mask & AA_MAY_REPLACE_POLICY ? OP_PROF_REPL : OP_PROF_LOAD; - aa_get_loaddata(udata); + aa_get_profile_loaddata(udata); /* released below */ error = aa_unpack(udata, &lh, &ns_name); if (error) @@ -1223,10 +1223,10 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, if (aa_rawdata_eq(rawdata_ent, udata)) { struct aa_loaddata *tmp; - tmp = __aa_get_loaddata(rawdata_ent); + tmp = aa_get_profile_loaddata(rawdata_ent); /* check we didn't fail the race */ if (tmp) { - aa_put_loaddata(udata); + aa_put_profile_loaddata(udata); udata = tmp; break; } @@ -1239,7 +1239,7 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, struct aa_profile *p; if (aa_g_export_binary) - ent->new->rawdata = aa_get_loaddata(udata); + ent->new->rawdata = aa_get_profile_loaddata(udata); error = __lookup_replace(ns, ent->new->base.hname, !(mask & AA_MAY_REPLACE_POLICY), &ent->old, &info); @@ -1372,7 +1372,7 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, out: aa_put_ns(ns); - aa_put_loaddata(udata); + aa_put_profile_loaddata(udata); kfree(ns_name); if (error) diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 5d90ea55de82..69a040194e36 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -109,22 +109,8 @@ bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r) return memcmp(l->data, r->data, r->compressed_size ?: r->size) == 0; } -/* - * need to take the ns mutex lock which is NOT safe most places that - * put_loaddata is called, so we have to delay freeing it - */ -static void do_loaddata_free(struct work_struct *work) +static void do_loaddata_free(struct aa_loaddata *d) { - struct aa_loaddata *d = container_of(work, struct aa_loaddata, work); - struct aa_ns *ns = aa_get_ns(d->ns); - - if (ns) { - mutex_lock_nested(&ns->lock, ns->level); - __aa_fs_remove_rawdata(d); - mutex_unlock(&ns->lock); - aa_put_ns(ns); - } - kfree_sensitive(d->hash); kfree_sensitive(d->name); kvfree(d->data); @@ -135,8 +121,35 @@ void aa_loaddata_kref(struct kref *kref) { struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count); + do_loaddata_free(d); +} + +/* + * need to take the ns mutex lock which is NOT safe most places that + * put_loaddata is called, so we have to delay freeing it + */ +static void do_ploaddata_rmfs(struct work_struct *work) +{ + struct aa_loaddata *d = container_of(work, struct aa_loaddata, work); + struct aa_ns *ns = aa_get_ns(d->ns); + + if (ns) { + mutex_lock_nested(&ns->lock, ns->level); + /* remove fs ref to loaddata */ + __aa_fs_remove_rawdata(d); + mutex_unlock(&ns->lock); + aa_put_ns(ns); + } + /* called by dropping last pcount, so drop its associated icount */ + aa_put_i_loaddata(d); +} + +void aa_ploaddata_kref(struct kref *kref) +{ + struct aa_loaddata *d = container_of(kref, struct aa_loaddata, pcount); + if (d) { - INIT_WORK(&d->work, do_loaddata_free); + INIT_WORK(&d->work, do_ploaddata_rmfs); schedule_work(&d->work); } } @@ -154,6 +167,7 @@ struct aa_loaddata *aa_loaddata_alloc(size_t size) return ERR_PTR(-ENOMEM); } kref_init(&d->count); + kref_init(&d->pcount); INIT_LIST_HEAD(&d->list); return d; From 8e135b8aee5a06c52a4347a5a6d51223c6f36ba3 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Sun, 1 Mar 2026 16:10:51 -0800 Subject: [PATCH 11/11] apparmor: fix race between freeing data and fs accessing it MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit AppArmor was putting the reference to i_private data on its end after removing the original entry from the file system. However the inode can aand does live beyond that point and it is possible that some of the fs call back functions will be invoked after the reference has been put, which results in a race between freeing the data and accessing it through the fs. While the rawdata/loaddata is the most likely candidate to fail the race, as it has the fewest references. If properly crafted it might be possible to trigger a race for the other types stored in i_private. Fix this by moving the put of i_private referenced data to the correct place which is during inode eviction. Fixes: c961ee5f21b20 ("apparmor: convert from securityfs to apparmorfs for policy ns files") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Signed-off-by: John Johansen --- security/apparmor/apparmorfs.c | 194 +++++++++++++--------- security/apparmor/include/label.h | 16 +- security/apparmor/include/lib.h | 12 ++ security/apparmor/include/policy.h | 8 +- security/apparmor/include/policy_unpack.h | 6 +- security/apparmor/label.c | 12 +- security/apparmor/policy_unpack.c | 6 +- 7 files changed, 153 insertions(+), 101 deletions(-) diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 7a6ca7c5500d..242c71b3fb6e 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -32,6 +32,7 @@ #include "include/crypto.h" #include "include/ipc.h" #include "include/label.h" +#include "include/lib.h" #include "include/policy.h" #include "include/policy_ns.h" #include "include/resource.h" @@ -62,6 +63,7 @@ * securityfs and apparmorfs filesystems. */ +#define IREF_POISON 101 /* * support fns @@ -153,6 +155,71 @@ static int aafs_show_path(struct seq_file *seq, struct dentry *dentry) return 0; } +static struct aa_ns *get_ns_common_ref(struct aa_common_ref *ref) +{ + if (ref) { + struct aa_label *reflabel = container_of(ref, struct aa_label, + count); + return aa_get_ns(labels_ns(reflabel)); + } + + return NULL; +} + +static struct aa_proxy *get_proxy_common_ref(struct aa_common_ref *ref) +{ + if (ref) + return aa_get_proxy(container_of(ref, struct aa_proxy, count)); + + return NULL; +} + +static struct aa_loaddata *get_loaddata_common_ref(struct aa_common_ref *ref) +{ + if (ref) + return aa_get_i_loaddata(container_of(ref, struct aa_loaddata, + count)); + return NULL; +} + +static void aa_put_common_ref(struct aa_common_ref *ref) +{ + if (!ref) + return; + + switch (ref->reftype) { + case REF_RAWDATA: + aa_put_i_loaddata(container_of(ref, struct aa_loaddata, + count)); + break; + case REF_PROXY: + aa_put_proxy(container_of(ref, struct aa_proxy, + count)); + break; + case REF_NS: + /* ns count is held on its unconfined label */ + aa_put_ns(labels_ns(container_of(ref, struct aa_label, count))); + break; + default: + AA_BUG(true, "unknown refcount type"); + break; + } +} + +static void aa_get_common_ref(struct aa_common_ref *ref) +{ + kref_get(&ref->count); +} + +static void aafs_evict(struct inode *inode) +{ + struct aa_common_ref *ref = inode->i_private; + + clear_inode(inode); + aa_put_common_ref(ref); + inode->i_private = (void *) IREF_POISON; +} + static void aafs_free_inode(struct inode *inode) { if (S_ISLNK(inode->i_mode)) @@ -162,6 +229,7 @@ static void aafs_free_inode(struct inode *inode) static const struct super_operations aafs_super_ops = { .statfs = simple_statfs, + .evict_inode = aafs_evict, .free_inode = aafs_free_inode, .show_path = aafs_show_path, }; @@ -262,7 +330,8 @@ static int __aafs_setup_d_inode(struct inode *dir, struct dentry *dentry, * aafs_remove(). Will return ERR_PTR on failure. */ static struct dentry *aafs_create(const char *name, umode_t mode, - struct dentry *parent, void *data, void *link, + struct dentry *parent, + struct aa_common_ref *data, void *link, const struct file_operations *fops, const struct inode_operations *iops) { @@ -299,6 +368,9 @@ static struct dentry *aafs_create(const char *name, umode_t mode, goto fail_dentry; inode_unlock(dir); + if (data) + aa_get_common_ref(data); + return dentry; fail_dentry: @@ -323,7 +395,8 @@ static struct dentry *aafs_create(const char *name, umode_t mode, * see aafs_create */ static struct dentry *aafs_create_file(const char *name, umode_t mode, - struct dentry *parent, void *data, + struct dentry *parent, + struct aa_common_ref *data, const struct file_operations *fops) { return aafs_create(name, mode, parent, data, NULL, fops, NULL); @@ -453,7 +526,7 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size, static ssize_t profile_load(struct file *f, const char __user *buf, size_t size, loff_t *pos) { - struct aa_ns *ns = aa_get_ns(f->f_inode->i_private); + struct aa_ns *ns = get_ns_common_ref(f->f_inode->i_private); int error = policy_update(AA_MAY_LOAD_POLICY, buf, size, pos, ns, f->f_cred); @@ -471,7 +544,7 @@ static const struct file_operations aa_fs_profile_load = { static ssize_t profile_replace(struct file *f, const char __user *buf, size_t size, loff_t *pos) { - struct aa_ns *ns = aa_get_ns(f->f_inode->i_private); + struct aa_ns *ns = get_ns_common_ref(f->f_inode->i_private); int error = policy_update(AA_MAY_LOAD_POLICY | AA_MAY_REPLACE_POLICY, buf, size, pos, ns, f->f_cred); aa_put_ns(ns); @@ -491,7 +564,7 @@ static ssize_t profile_remove(struct file *f, const char __user *buf, struct aa_loaddata *data; struct aa_label *label; ssize_t error; - struct aa_ns *ns = aa_get_ns(f->f_inode->i_private); + struct aa_ns *ns = get_ns_common_ref(f->f_inode->i_private); label = begin_current_label_crit_section(); /* high level check about policy management - fine grained in @@ -581,7 +654,7 @@ static int ns_revision_open(struct inode *inode, struct file *file) if (!rev) return -ENOMEM; - rev->ns = aa_get_ns(inode->i_private); + rev->ns = get_ns_common_ref(inode->i_private); if (!rev->ns) rev->ns = aa_get_current_ns(); file->private_data = rev; @@ -1067,7 +1140,7 @@ static const struct file_operations seq_profile_ ##NAME ##_fops = { \ static int seq_profile_open(struct inode *inode, struct file *file, int (*show)(struct seq_file *, void *)) { - struct aa_proxy *proxy = aa_get_proxy(inode->i_private); + struct aa_proxy *proxy = get_proxy_common_ref(inode->i_private); int error = single_open(file, show, proxy); if (error) { @@ -1259,7 +1332,7 @@ static const struct file_operations seq_rawdata_ ##NAME ##_fops = { \ static int seq_rawdata_open(struct inode *inode, struct file *file, int (*show)(struct seq_file *, void *)) { - struct aa_loaddata *data = aa_get_i_loaddata(inode->i_private); + struct aa_loaddata *data = get_loaddata_common_ref(inode->i_private); int error; if (!data) @@ -1392,7 +1465,7 @@ static int rawdata_open(struct inode *inode, struct file *file) if (!aa_current_policy_view_capable(NULL)) return -EACCES; - loaddata = aa_get_i_loaddata(inode->i_private); + loaddata = get_loaddata_common_ref(inode->i_private); if (!loaddata) return -ENOENT; @@ -1437,7 +1510,6 @@ static void remove_rawdata_dents(struct aa_loaddata *rawdata) if (!IS_ERR_OR_NULL(rawdata->dents[i])) { aafs_remove(rawdata->dents[i]); rawdata->dents[i] = NULL; - aa_put_i_loaddata(rawdata); } } } @@ -1476,45 +1548,41 @@ int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata) if (IS_ERR(dir)) /* ->name freed when rawdata freed */ return PTR_ERR(dir); - aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_DIR] = dir; - dent = aafs_create_file("abi", S_IFREG | 0444, dir, rawdata, + dent = aafs_create_file("abi", S_IFREG | 0444, dir, &rawdata->count, &seq_rawdata_abi_fops); if (IS_ERR(dent)) goto fail; - aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_ABI] = dent; - dent = aafs_create_file("revision", S_IFREG | 0444, dir, rawdata, - &seq_rawdata_revision_fops); + dent = aafs_create_file("revision", S_IFREG | 0444, dir, + &rawdata->count, + &seq_rawdata_revision_fops); if (IS_ERR(dent)) goto fail; - aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_REVISION] = dent; if (aa_g_hash_policy) { dent = aafs_create_file("sha256", S_IFREG | 0444, dir, - rawdata, &seq_rawdata_hash_fops); + &rawdata->count, + &seq_rawdata_hash_fops); if (IS_ERR(dent)) goto fail; - aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_HASH] = dent; } dent = aafs_create_file("compressed_size", S_IFREG | 0444, dir, - rawdata, + &rawdata->count, &seq_rawdata_compressed_size_fops); if (IS_ERR(dent)) goto fail; - aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_COMPRESSED_SIZE] = dent; - dent = aafs_create_file("raw_data", S_IFREG | 0444, - dir, rawdata, &rawdata_fops); + dent = aafs_create_file("raw_data", S_IFREG | 0444, dir, + &rawdata->count, &rawdata_fops); if (IS_ERR(dent)) goto fail; - aa_get_i_loaddata(rawdata); rawdata->dents[AAFS_LOADDATA_DATA] = dent; d_inode(dent)->i_size = rawdata->size; @@ -1525,7 +1593,6 @@ int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata) fail: remove_rawdata_dents(rawdata); - aa_put_i_loaddata(rawdata); return PTR_ERR(dent); } #endif /* CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */ @@ -1549,13 +1616,10 @@ void __aafs_profile_rmdir(struct aa_profile *profile) __aafs_profile_rmdir(child); for (i = AAFS_PROF_SIZEOF - 1; i >= 0; --i) { - struct aa_proxy *proxy; if (!profile->dents[i]) continue; - proxy = d_inode(profile->dents[i])->i_private; aafs_remove(profile->dents[i]); - aa_put_proxy(proxy); profile->dents[i] = NULL; } } @@ -1589,14 +1653,7 @@ static struct dentry *create_profile_file(struct dentry *dir, const char *name, struct aa_profile *profile, const struct file_operations *fops) { - struct aa_proxy *proxy = aa_get_proxy(profile->label.proxy); - struct dentry *dent; - - dent = aafs_create_file(name, S_IFREG | 0444, dir, proxy, fops); - if (IS_ERR(dent)) - aa_put_proxy(proxy); - - return dent; + return aafs_create_file(name, S_IFREG | 0444, dir, &profile->label.proxy->count, fops); } #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY @@ -1646,7 +1703,8 @@ static const char *rawdata_get_link_base(struct dentry *dentry, struct delayed_call *done, const char *name) { - struct aa_proxy *proxy = inode->i_private; + struct aa_common_ref *ref = inode->i_private; + struct aa_proxy *proxy = container_of(ref, struct aa_proxy, count); struct aa_label *label; struct aa_profile *profile; char *target; @@ -1788,27 +1846,24 @@ int __aafs_profile_mkdir(struct aa_profile *profile, struct dentry *parent) if (profile->rawdata) { if (aa_g_hash_policy) { dent = aafs_create("raw_sha256", S_IFLNK | 0444, dir, - profile->label.proxy, NULL, NULL, - &rawdata_link_sha256_iops); + &profile->label.proxy->count, NULL, + NULL, &rawdata_link_sha256_iops); if (IS_ERR(dent)) goto fail; - aa_get_proxy(profile->label.proxy); profile->dents[AAFS_PROF_RAW_HASH] = dent; } dent = aafs_create("raw_abi", S_IFLNK | 0444, dir, - profile->label.proxy, NULL, NULL, + &profile->label.proxy->count, NULL, NULL, &rawdata_link_abi_iops); if (IS_ERR(dent)) goto fail; - aa_get_proxy(profile->label.proxy); profile->dents[AAFS_PROF_RAW_ABI] = dent; dent = aafs_create("raw_data", S_IFLNK | 0444, dir, - profile->label.proxy, NULL, NULL, + &profile->label.proxy->count, NULL, NULL, &rawdata_link_data_iops); if (IS_ERR(dent)) goto fail; - aa_get_proxy(profile->label.proxy); profile->dents[AAFS_PROF_RAW_DATA] = dent; } #endif /*CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */ @@ -1845,7 +1900,7 @@ static struct dentry *ns_mkdir_op(struct mnt_idmap *idmap, struct inode *dir, if (error) return ERR_PTR(error); - parent = aa_get_ns(dir->i_private); + parent = get_ns_common_ref(dir->i_private); AA_BUG(d_inode(ns_subns_dir(parent)) != dir); /* we have to unlock and then relock to get locking order right @@ -1895,7 +1950,7 @@ static int ns_rmdir_op(struct inode *dir, struct dentry *dentry) if (error) return error; - parent = aa_get_ns(dir->i_private); + parent = get_ns_common_ref(dir->i_private); /* rmdir calls the generic securityfs functions to remove files * from the apparmor dir. It is up to the apparmor ns locking * to avoid races. @@ -1965,27 +2020,6 @@ void __aafs_ns_rmdir(struct aa_ns *ns) __aa_fs_list_remove_rawdata(ns); - if (ns_subns_dir(ns)) { - sub = d_inode(ns_subns_dir(ns))->i_private; - aa_put_ns(sub); - } - if (ns_subload(ns)) { - sub = d_inode(ns_subload(ns))->i_private; - aa_put_ns(sub); - } - if (ns_subreplace(ns)) { - sub = d_inode(ns_subreplace(ns))->i_private; - aa_put_ns(sub); - } - if (ns_subremove(ns)) { - sub = d_inode(ns_subremove(ns))->i_private; - aa_put_ns(sub); - } - if (ns_subrevision(ns)) { - sub = d_inode(ns_subrevision(ns))->i_private; - aa_put_ns(sub); - } - for (i = AAFS_NS_SIZEOF - 1; i >= 0; --i) { aafs_remove(ns->dents[i]); ns->dents[i] = NULL; @@ -2010,40 +2044,40 @@ static int __aafs_ns_mkdir_entries(struct aa_ns *ns, struct dentry *dir) return PTR_ERR(dent); ns_subdata_dir(ns) = dent; - dent = aafs_create_file("revision", 0444, dir, ns, + dent = aafs_create_file("revision", 0444, dir, + &ns->unconfined->label.count, &aa_fs_ns_revision_fops); if (IS_ERR(dent)) return PTR_ERR(dent); - aa_get_ns(ns); ns_subrevision(ns) = dent; - dent = aafs_create_file(".load", 0640, dir, ns, - &aa_fs_profile_load); + dent = aafs_create_file(".load", 0640, dir, + &ns->unconfined->label.count, + &aa_fs_profile_load); if (IS_ERR(dent)) return PTR_ERR(dent); - aa_get_ns(ns); ns_subload(ns) = dent; - dent = aafs_create_file(".replace", 0640, dir, ns, - &aa_fs_profile_replace); + dent = aafs_create_file(".replace", 0640, dir, + &ns->unconfined->label.count, + &aa_fs_profile_replace); if (IS_ERR(dent)) return PTR_ERR(dent); - aa_get_ns(ns); ns_subreplace(ns) = dent; - dent = aafs_create_file(".remove", 0640, dir, ns, - &aa_fs_profile_remove); + dent = aafs_create_file(".remove", 0640, dir, + &ns->unconfined->label.count, + &aa_fs_profile_remove); if (IS_ERR(dent)) return PTR_ERR(dent); - aa_get_ns(ns); ns_subremove(ns) = dent; /* use create_dentry so we can supply private data */ - dent = aafs_create("namespaces", S_IFDIR | 0755, dir, ns, NULL, NULL, - &ns_dir_inode_operations); + dent = aafs_create("namespaces", S_IFDIR | 0755, dir, + &ns->unconfined->label.count, + NULL, NULL, &ns_dir_inode_operations); if (IS_ERR(dent)) return PTR_ERR(dent); - aa_get_ns(ns); ns_subns_dir(ns) = dent; return 0; diff --git a/security/apparmor/include/label.h b/security/apparmor/include/label.h index c0812dbc1b5b..335f21930702 100644 --- a/security/apparmor/include/label.h +++ b/security/apparmor/include/label.h @@ -102,7 +102,7 @@ enum label_flags { struct aa_label; struct aa_proxy { - struct kref count; + struct aa_common_ref count; struct aa_label __rcu *label; }; @@ -125,7 +125,7 @@ struct label_it { * vec: vector of profiles comprising the compound label */ struct aa_label { - struct kref count; + struct aa_common_ref count; struct rb_node node; struct rcu_head rcu; struct aa_proxy *proxy; @@ -357,7 +357,7 @@ int aa_label_match(struct aa_profile *profile, struct aa_ruleset *rules, */ static inline struct aa_label *__aa_get_label(struct aa_label *l) { - if (l && kref_get_unless_zero(&l->count)) + if (l && kref_get_unless_zero(&l->count.count)) return l; return NULL; @@ -366,7 +366,7 @@ static inline struct aa_label *__aa_get_label(struct aa_label *l) static inline struct aa_label *aa_get_label(struct aa_label *l) { if (l) - kref_get(&(l->count)); + kref_get(&(l->count.count)); return l; } @@ -386,7 +386,7 @@ static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l) rcu_read_lock(); do { c = rcu_dereference(*l); - } while (c && !kref_get_unless_zero(&c->count)); + } while (c && !kref_get_unless_zero(&c->count.count)); rcu_read_unlock(); return c; @@ -426,7 +426,7 @@ static inline struct aa_label *aa_get_newest_label(struct aa_label *l) static inline void aa_put_label(struct aa_label *l) { if (l) - kref_put(&l->count, aa_label_kref); + kref_put(&l->count.count, aa_label_kref); } /* wrapper fn to indicate semantics of the check */ @@ -443,7 +443,7 @@ void aa_proxy_kref(struct kref *kref); static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) { if (proxy) - kref_get(&(proxy->count)); + kref_get(&(proxy->count.count)); return proxy; } @@ -451,7 +451,7 @@ static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy) static inline void aa_put_proxy(struct aa_proxy *proxy) { if (proxy) - kref_put(&proxy->count, aa_proxy_kref); + kref_put(&proxy->count.count, aa_proxy_kref); } void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new); diff --git a/security/apparmor/include/lib.h b/security/apparmor/include/lib.h index 1c5d1f60f6a7..8c6ce8484552 100644 --- a/security/apparmor/include/lib.h +++ b/security/apparmor/include/lib.h @@ -102,6 +102,18 @@ void aa_info_message(const char *str); /* Security blob offsets */ extern struct lsm_blob_sizes apparmor_blob_sizes; +enum reftype { + REF_NS, + REF_PROXY, + REF_RAWDATA, +}; + +/* common reference count used by data the shows up in aafs */ +struct aa_common_ref { + struct kref count; + enum reftype reftype; +}; + /** * aa_strneq - compare null terminated @str to a non null terminated substring * @str: a null terminated string diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h index fda9e75b8879..3895f8774a3f 100644 --- a/security/apparmor/include/policy.h +++ b/security/apparmor/include/policy.h @@ -379,7 +379,7 @@ static inline bool profile_mediates_safe(struct aa_profile *profile, static inline struct aa_profile *aa_get_profile(struct aa_profile *p) { if (p) - kref_get(&(p->label.count)); + kref_get(&(p->label.count.count)); return p; } @@ -393,7 +393,7 @@ static inline struct aa_profile *aa_get_profile(struct aa_profile *p) */ static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p) { - if (p && kref_get_unless_zero(&p->label.count)) + if (p && kref_get_unless_zero(&p->label.count.count)) return p; return NULL; @@ -413,7 +413,7 @@ static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p) rcu_read_lock(); do { c = rcu_dereference(*p); - } while (c && !kref_get_unless_zero(&c->label.count)); + } while (c && !kref_get_unless_zero(&c->label.count.count)); rcu_read_unlock(); return c; @@ -426,7 +426,7 @@ static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p) static inline void aa_put_profile(struct aa_profile *p) { if (p) - kref_put(&p->label.count, aa_label_kref); + kref_put(&p->label.count.count, aa_label_kref); } static inline int AUDIT_MODE(struct aa_profile *profile) diff --git a/security/apparmor/include/policy_unpack.h b/security/apparmor/include/policy_unpack.h index 4f800fbb805a..e5a95dc4da1f 100644 --- a/security/apparmor/include/policy_unpack.h +++ b/security/apparmor/include/policy_unpack.h @@ -108,7 +108,7 @@ struct aa_ext { * fs entries and drops the associated @count ref. */ struct aa_loaddata { - struct kref count; + struct aa_common_ref count; struct kref pcount; struct list_head list; struct work_struct work; @@ -143,7 +143,7 @@ aa_get_i_loaddata(struct aa_loaddata *data) { if (data) - kref_get(&(data->count)); + kref_get(&(data->count.count)); return data; } @@ -171,7 +171,7 @@ struct aa_loaddata *aa_loaddata_alloc(size_t size); static inline void aa_put_i_loaddata(struct aa_loaddata *data) { if (data) - kref_put(&data->count, aa_loaddata_kref); + kref_put(&data->count.count, aa_loaddata_kref); } static inline void aa_put_profile_loaddata(struct aa_loaddata *data) diff --git a/security/apparmor/label.c b/security/apparmor/label.c index e478283bc514..3a721fdf1833 100644 --- a/security/apparmor/label.c +++ b/security/apparmor/label.c @@ -52,7 +52,8 @@ static void free_proxy(struct aa_proxy *proxy) void aa_proxy_kref(struct kref *kref) { - struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count); + struct aa_proxy *proxy = container_of(kref, struct aa_proxy, + count.count); free_proxy(proxy); } @@ -63,7 +64,8 @@ struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp) new = kzalloc_obj(struct aa_proxy, gfp); if (new) { - kref_init(&new->count); + kref_init(&new->count.count); + new->count.reftype = REF_PROXY; rcu_assign_pointer(new->label, aa_get_label(label)); } return new; @@ -375,7 +377,8 @@ static void label_free_rcu(struct rcu_head *head) void aa_label_kref(struct kref *kref) { - struct aa_label *label = container_of(kref, struct aa_label, count); + struct aa_label *label = container_of(kref, struct aa_label, + count.count); struct aa_ns *ns = labels_ns(label); if (!ns) { @@ -412,7 +415,8 @@ bool aa_label_init(struct aa_label *label, int size, gfp_t gfp) label->size = size; /* doesn't include null */ label->vec[size] = NULL; /* null terminate */ - kref_init(&label->count); + kref_init(&label->count.count); + label->count.reftype = REF_NS; /* for aafs purposes */ RB_CLEAR_NODE(&label->node); return true; diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 69a040194e36..076d3ff14da6 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -119,7 +119,8 @@ static void do_loaddata_free(struct aa_loaddata *d) void aa_loaddata_kref(struct kref *kref) { - struct aa_loaddata *d = container_of(kref, struct aa_loaddata, count); + struct aa_loaddata *d = container_of(kref, struct aa_loaddata, + count.count); do_loaddata_free(d); } @@ -166,7 +167,8 @@ struct aa_loaddata *aa_loaddata_alloc(size_t size) kfree(d); return ERR_PTR(-ENOMEM); } - kref_init(&d->count); + kref_init(&d->count.count); + d->count.reftype = REF_RAWDATA; kref_init(&d->pcount); INIT_LIST_HEAD(&d->list);