hci_conn_del() caller must hold hdev->lock, check the conn was not
concurrently deleted, and usually inform socket the conn is going to be
deleted.
Use hci_abort_conn_sync() instead of calling hci_conn_del() without
locks etc.
Fixes: 8e8b92ee60 ("Bluetooth: hci_sync: Add hci_le_create_conn_sync")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Avoids giving freed pointers to hci_conn_valid(), which kmalloc may have
reused.
Hold refcount to avoid that.
Fixes: d3413703d5 ("Bluetooth: ISO: Add support to bind to trigger PAST")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
There is theoretical UAF if the conn is freed while the hci_sync task is
running.
Hold refcount to avoid that.
Fixes: 6d0417e4e1 ("Bluetooth: hci_conn: Fix not setting conn_timeout for Broadcast Receiver")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
There is theoretical UAF if the conn is freed while the hci_sync task is
running.
Hold refcount to avoid that. Handle NULL hcon, return 0 + do nothing to
match the previous behavior.
Fixes: 024421cf39 ("Bluetooth: hci_conn: Fix not setting timeout for BIG Create Sync")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
There is theoretical UAF if the conn is freed while the hci_sync task
is running.
Hold refcount to avoid that.
Fixes: 881559af5f ("Bluetooth: hci_sync: Attempt to dequeue connection attempt")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
There is theoretical UAF if the conn is freed while the hci_sync task is
running.
Hold refcount to avoid that.
Fixes: 227a0cdf4a ("Bluetooth: MGMT: Fix not generating command complete for MGMT_OP_DISCONNECT")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
hci_conn::iso_data is accessed and modified without lock or RCU.
This leads to a race
[Task hdev->workqueue] [Task 2]
iso_recv iso_conn_put(conn)
conn = LOAD hcon->iso_data iso_conn_free(conn)
iso_conn_hold_unless_zero(conn) hcon->iso_data = NULL
kfree(conn)
kref_get_unless_zero(&conn->ref) /* UAF */
and also to races in iso_conn_add() vs. iso_conn_free().
Fix by adding spinlock hci_conn::proto_lock and using it to guard
hci_conn::iso_data.
Fixes: dc26097bdb ("Bluetooth: ISO: Use kref to track lifetime of iso_conn")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
iso_conn_del() and iso_chan_del() have a race that results to double-put
of iso_conn:
[Task hdev->workqueue] [Task 2]
iso_conn_del iso_chan_del
iso_conn_hold_unless_zero iso_conn_lock
iso_conn_lock conn->sk = NULL
iso_conn_unlock
sk = iso_sock_hold(conn) <---------´
if (!sk) iso_conn_put iso_conn_put
iso_conn_put /* UAF */
The extra put for !sk in iso_conn_del() is currently required since
failing iso_chan_add() may leave iso_conn not associated with any sk.
Fix by having iso_pi(sk)->conn own refcount when non-NULL, so
iso_conn_del does not need to put it. Adjust the iso_conn_add()
refcounting so that conn is put if it does not get associated with an
sk.
Fixes: dc26097bdb ("Bluetooth: ISO: Use kref to track lifetime of iso_conn")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
After iso_conn_del(), ISO sockets should not dereference the hcon any
more. Currently, clearing iso_conn::hcon relies on iso_conn_del()
releasing the last reference to the iso_conn.
Simplify this by explicitly clearing conn->hcon in iso_conn_del(), to
avoid more complex reasoning on races about who holds the last
reference.
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
iso_sock_timeout() takes lock_sock, so sync disabling the timer while
holding that lock may deadlock.
iso_sock_timeout() may also run concurrently with iso_conn_del(), which
leads to UAF
[Task 1] [Task hdev->workqueue]
iso_sock_timeout iso_conn_del
iso_conn_hold_unless_zero iso_chan_del
`------------> iso_conn_put
caller frees hcon
iso_conn_put
iso_conn_free
conn->hcon->iso_data = NULL; /* UAF */
Fix the deadlock by removing the disable from the lock_sock sections.
Move the timer from iso_conn to iso_pinfo to decouple it from iso_conn
which may need to be freed in lock_sock section. Convert some of the
clear_timer to disable_timer.
Fixes: dc26097bdb ("Bluetooth: ISO: Use kref to track lifetime of iso_conn")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
iso_sock_kill() tests !sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket ||
sock_flag(sk, SOCK_DEAD) for early return, but this is always true since
sock_orphan(sk) sets SOCK_DEAD, so the sk reference released by socket
always leaks, iso_sock_destruct is never called.
The socket reference also leaks when __iso_sock_close() does not set
SOCK_ZAPPED, since iso_conn_del() does not call iso_sock_kill() after
zapping.
Fix by replacing SOCK_DEAD by BT_SK_KILLED flag that is not used for
something else, and lock_sock to ensure iso_sock_kill() puts sk only
after socket release only once. Release and iso_conn_del may run
concurrently. Call iso_sock_kill() from iso_conn_del() to clean sk up
after zapping.
Remove call to iso_sock_kill() from iso_sock_close(), as it's generally
no-op there.
Fixes: ccf74f2390 ("Bluetooth: Add BTPROTO_ISO socket type")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
sk deref in iso_conn_ready must be done either under conn->lock, or
holding a refcount, to avoid concurrent close. conn->sk is currently
accessed without either:
[Task 1] [Task 2]
iso_sock_release
iso_conn_ready
sk = conn->sk
lock_sock(sk)
conn->sk = NULL
lock_sock(sk)
release_sock(sk)
iso_sock_kill(sk)
UAF on sk deref
Fix possible UAF by holding sk refcount in iso_conn_ready(). Also
recheck after lock_sock that the socket is still valid. Adjust locking
so conn->sk is cleared only under lock_sock.
Fixes: 27c24fda62 ("Bluetooth: switch to lock_sock in SCO")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
iso_sock_rebind_bis() updates socket iso_pi(sk)->bc_num_bis before
validating the BIS values, so it's possible to end up with bc_num_bis
inconsistent.
Assign to iso_pi(sk)->bc_num_bis only after validation.
Fixes: 80837140c1 ("Bluetooth: ISO: Allow binding a PA sync socket")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
In iso.c check_bcast_qos(), missing bcast.timeout is not set to its
default value, and appears typoed as bcast.sync_timeout.
Fix the typo.
Fixes: b37cab587a ("Bluetooth: ISO: Don't reject BT_ISO_QOS if parameters are unset")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Accessing iso_pi(sk)->conn requires lock_sock, which is not taken in the
"ev3" part of iso_connect_ind. It may also be NULL if socket has
transitioned away from the LISTEN/CONNECT states before locking.
Fix by adding lock/release. Recheck hcon is valid after lock acquire
where needed.
Fixes: 168d9bf9c7 ("Bluetooth: ISO: Reassemble PA data for bcast sink")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Accessing iso_pi(sk)->conn requires lock_sock, which is not held here.
Fix by adding the lock/release.
Fixes: 2df108c227 ("Bluetooth: ISO: Fix using BT_SK_PA_SYNC to detect BIS sockets")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Commit d57e506f6a ("Bluetooth: ISO: clear iso_data always when detaching conn from hcon")
merged a version of the UAF fix that breaks releasing connected
ISO sockets. Since hci_conn::iso_data is set to NULL, iso_chan_del() won't
be called when the hci_conn disconnects, and the ISO socket does not emit
POLLHUP correctly.
Fix by retaining full hci_conn <-> iso_conn association while in
BT_DISCONNECT state, so that local disconnect via shutdown() follows
similar ISO socket code path as remote disconnect. Use a separate flag
to track whether hci_conn_drop() is needed, instead of setting
iso_conn::hcon = NULL
In iso_sock_ready(), disallow disconnecting socket going BT_CONNECTED,
in case hcon connects while its drop is pending.
Fixes: d57e506f6a ("Bluetooth: ISO: clear iso_data always when detaching conn from hcon")
Fixes: fbdc4bc472 ("Bluetooth: ISO: Use defer setup to separate PA sync and BIG sync")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
hci_find_adv_instance() returns an adv_info pointer that is valid only
while hdev->lock is held. The advertising command-sync paths perform
instance lookups without that lock and, in some cases, retain the pointer
while waiting for a controller response.
An advertising termination event can therefore interleave as follows:
hci_cmd_sync_work hci_rx_work
hci_find_adv_instance()
__hci_cmd_sync_status()
wait for controller reply hci_dev_lock()
hci_remove_adv_instance()
kfree(adv)
adv->scan_rsp_changed = false
KASAN reported:
BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
hci_schedule_adv_instance_sync+0x390/0x4c0
hci_cmd_sync_work+0x173/0x300
Allocated by task 87:
hci_add_adv_instance+0x538/0xac0
add_advertising+0x885/0x1160
Freed by task 89:
kfree+0x131/0x3c0
hci_remove_adv_instance+0x1d8/0x3b0
hci_le_ext_adv_term_evt+0x17b/0x730
Protect the instance lookup and payload construction in the extended
advertising, scan response, and periodic advertising data paths. Snapshot
the advertising parameters under hdev->lock, but release the lock before
waiting for the controller.
Clear advertising-data dirty bits before issuing their commands and
restore them after a failure using a fresh lookup. Likewise, update the
reported transmit power through a fresh lookup after the parameter command
completes. No adv_info pointer then survives an HCI command wait.
Fixes: cba6b75871 ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 2")
Cc: stable@vger.kernel.org
Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
rfcomm_recv_frame() casts skb->data to struct rfcomm_hdr and dereferences
hdr->addr and hdr->ctrl without validating skb->len first. A truncated
frame with skb->len less than the minimum header size causes an
out-of-bounds read of uninitialized memory. Additionally, a zero-length
frame causes skb->len-- to underflow to UINT_MAX, making
skb_tail_pointer() read far past the buffer.
Commit 23882b828c ("Bluetooth: RFCOMM: validate skb length in MCC
handlers") fixed the same class of missing-length-check bugs in the MCC
sub-handlers, but the top-level rfcomm_recv_frame() was left unfixed.
KMSAN reports:
BUG: KMSAN: uninit-value in rfcomm_run
...
Uninit was created at:
__alloc_skb+0x474/0xb60
vhci_write+0xe9/0x870
Fix this by rejecting frames smaller than sizeof(struct rfcomm_hdr) + 1
(the minimum frame must have a 3-byte header and a 1-byte FCS).
Signed-off-by: Jiale Yao <yaojiale02@163.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_le_connect_rsp() obtains a channel via
__l2cap_get_chan_by_ident() but neither holds a reference nor uses
l2cap_chan_hold_unless_zero() before locking and operating on it.
A concurrent l2cap_chan_del() triggered by a remote disconnect can
free the channel between the lookup and l2cap_chan_lock(), causing
a use-after-free.
The BR/EDR counterpart l2cap_connect_rsp() and the sibling handler
l2cap_le_command_rej() already use l2cap_chan_hold_unless_zero()
to safely hold a reference, but l2cap_le_connect_rsp() was left
unprotected.
Fix by adding l2cap_chan_hold_unless_zero() after the ident lookup
and l2cap_chan_put() on the exit path, consistent with other L2CAP
response handlers.
Fixes: f1496dee9c ("Bluetooth: Add initial code for LE L2CAP Connect Request")
Assisted-by: Claude:deepseek-v4-pro
Signed-off-by: Jiale Yao <yaojiale02@163.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
When hidp_get_raw_report() waits for a numbered report,
hidp_process_data() compares the expected report number with skb->data[0].
A connected HIDP peer can reply with only a DATA transaction header,
leaving the skb empty after the header is removed.
KMSAN reports an uninitialized-value use in hidp_session_run(), with the
value originating in __alloc_skb() through vhci_write(). The transaction
header checks remove the empty-frame reports, but this report remains until
the payload check is added.
The comparison can also consume a peer-controlled byte beyond the declared
L2CAP PDU. A DATA | FEATURE response followed by an extra 0x01 byte made
the current code accept that byte as report ID 1 and complete
HIDIOCGFEATURE with a zero-byte result. With this change the malformed
response is rejected with -EIO, while a subsequent valid response still
succeeds.
Require a payload byte before comparing a numbered report ID. Unnumbered
reports continue to accept an empty payload.
Fixes: 0ff1731a1a ("HID: bt: Add support for hidraw HIDIOCGFEATURE and HIDIOCSFEATURE")
Cc: stable@vger.kernel.org
Signed-off-by: Sangho Lee <kudo3228@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
hidp_recv_ctrl_frame() and hidp_recv_intr_frame() read skb->data[0]
before checking that the L2CAP SDU contains a transaction header. A
connected HIDP peer can send an empty basic-mode SDU and make both paths
use an uninitialized byte from skb tailroom.
KMSAN reports the use in hidp_session_run(), with the uninitialized value
originating in __alloc_skb() through vhci_write(). The control path
produces two reports and the interrupt path produces one.
The byte can also be controlled by a malformed lower-layer packet. If an
HCI ACL packet contains an L2CAP PDU with a declared zero-length payload
followed by an extra 0x15 byte, l2cap_recv_acldata() reduces skb->len to
the declared PDU length before dispatch. The current HIDP path nevertheless
consumes the extra byte as HIDP_TRANS_HID_CONTROL |
HIDP_CTRL_VIRTUAL_CABLE_UNPLUG and terminates the HIDP session. With this
change, the same packet is discarded and a subsequent feature report
request succeeds.
Pull the transaction header with skb_pull_data() and discard frames that
do not contain it.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Sangho Lee <kudo3228@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
MGMT_OP_SET_LOCAL_NAME is handled asynchronously on powered controllers
and can run set_name_sync(). When the controller is BR/EDR capable,
set_name_sync() updates the local name and then rebuilds EIR data through
eir_create(). The EIR builder walks hdev->uuids, but the UUID list can
be changed and entries can be freed by MGMT_OP_ADD_UUID and
MGMT_OP_REMOVE_UUID.
pending_eir_or_class() is meant to serialize management commands that
can change EIR or the class of device, but it did not include
MGMT_OP_SET_LOCAL_NAME. In addition, it walked hdev->mgmt_pending
without hdev->mgmt_pending_lock even though pending commands are added
and removed under that mutex. A racing command completion can therefore
remove and free a pending command while pending_eir_or_class() is still
inspecting it, leading to a use-after-free in the pending-command list or
allowing a local name update to rebuild EIR while UUID entries are being
removed.
Take hdev->mgmt_pending_lock while scanning hdev->mgmt_pending and treat
MGMT_OP_SET_LOCAL_NAME as an EIR/class-affecting pending command on the
powered asynchronous path. Check for a conflicting pending command before
copying the new short name so a rejected SET_LOCAL_NAME request does not
modify hdev->short_name.
Fixes: 6fe26f694c ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi <zihanx@nebusec.ai>
Signed-off-by: Ren Wei <enjou1224z@gmail.com>
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The pairing completion and authentication failure callbacks look up the
pending MGMT_OP_PAIR_DEVICE command by walking hdev->mgmt_pending. The
lookup returned a command that was still linked on the shared pending list,
without keeping mgmt_pending_lock held for the later dereference and
removal.
A concurrent MGMT_OP_CANCEL_PAIR_DEVICE request can remove and free the
same pending command before the callback uses it. The reverse race is also
possible when cancel_pair_device() gets a command from pending_find() and a
callback removes it before the cancel path dereferences it. This can lead
to a use-after-free and a second list_del().
Make the pairing lookup helpers transfer ownership of the pending command
by removing it from hdev->mgmt_pending while holding mgmt_pending_lock.
The callbacks and cancel path then complete the command and free it
directly, so racing paths cannot find or free the same command again. Take
a temporary hci_conn reference in cancel_pair_device() because the command
completion drops the reference stored in the pending command.
Fixes: e9a416b5ce ("Bluetooth: Add mgmt_pair_device command")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi <xizh2024@lzu.edu.cn>
Reviewed-by: Ren Wei <enjou1224z@gmail.com>
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
When setting conn->hcon = NULL, also conn->hcon->iso_data = NULL is
necessary, otherwise later iso_conn_free() will UAF.
Fix clearing of iso_data in iso_sock_disconn()
Fixes KASAN: slab-use-after-free in iso_conn_hold_unless_zero on
iso_sock_release() followed by hci_abort_conn_sync().
Fixes: fbdc4bc472 ("Bluetooth: ISO: Use defer setup to separate PA sync and BIG sync")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
syzbot reported a memory leak [1] in the UDP tunnel NIC offload code.
When device registration fails (e.g. in register_netdevice()), netdev core
unwinds by sending a single NETDEV_UNREGISTER notification. If work was queued
during NETDEV_REGISTER (utn->work_pending is set), udp_tunnel_nic_unregister()
returns early:
if (utn->work_pending)
return;
Because failed registrations do not enter netdev_wait_allrefs_any(), no
subsequent NETDEV_UNREGISTER rebroadcast will ever occur. As a result, the
struct udp_tunnel_nic allocated in udp_tunnel_nic_alloc() is leaked
permanently.
Fix this by removing the early return. Instead, synchronously cancel any
pending work with cancel_delayed_work_sync() before freeing @utn.
To be able to call cancel_delayed_work_sync() while holding RTNL (the work also
needs RTNL), switch udp_tunnel_nic_device_sync_work() to rtnl_trylock(). If RTNL
is contended, requeue the work with a 1 jiffy delay (via queue_delayed_work())
to prevent high CPU contention while waiting for RTNL lock.
The utn->work_pending bookkeeping is no longer needed and is removed, as
the workqueue core already tracks the pending/running state of the work.
[1]
BUG: memory leak
unreferenced object 0xffff888127d5f840 (size 96):
comm "syz-executor", pid 5806, jiffies 4294942188
backtrace (crc 99fdb6c8):
__kmalloc_noprof+0x3bf/0x550
udp_tunnel_nic_alloc net/ipv4/udp_tunnel_nic.c:756 [inline]
udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:833 [inline]
udp_tunnel_nic_netdevice_event+0x804/0xab0 net/ipv4/udp_tunnel_nic.c:931
notifier_call_chain+0x59/0x160 kernel/notifier.c:85
call_netdevice_notifiers_info+0x7d/0xb0 net/core/dev.c:2250
register_netdevice+0xc10/0xeb0 net/core/dev.c:11478
Fixes: cc4e3835ef ("udp_tunnel: add central NIC RX port offload infrastructure")
Reported-by: syzbot+eca845fb8c18dd6b44c1@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6a632b15.dde6c935.cf6c8.0011.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260724091137.1792543-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
bpf_lwt_xmit_reroute() obtains a referenced dst from the route
lookup. When skb_cow_head() fails before that dst is installed on the
skb, the error path only frees the skb. The skb still owns its previous
dst, so the newly looked up dst reference is leaked.
Release the new dst reference before freeing the skb on this error
path.
Fixes: 3bd0b15281 ("bpf: add handling of BPF_LWT_REROUTE to lwt_bpf.c")
Cc: stable@vger.kernel.org
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Link: https://patch.msgid.link/20260723060445.21926-1-xuanqiang.luo@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
__smc_lgr_terminate() drops conns_lock after finding a connection in
lgr->conns_all, but before taking a reference on its socket. The connection
is embedded in the socket, and its registration reference protects it only
while the connection remains in the tree.
A concurrent close can unregister the connection and drop that reference,
freeing the socket before the termination worker reaches sock_hold().
The race is reachable when close overlaps link group termination.
Local stress testing reproduced the use-after-free and KASAN reported:
BUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc]
Write of size 4 by task kworker/3:3
Workqueue: events smc_lgr_terminate_work [smc]
__smc_lgr_terminate.part.0 [smc]
The socket was allocated by smc_create(), freed through
slab_free_after_rcu_debug(), and was followed by:
refcount_t: addition on 0; use-after-free.
__smc_lgr_terminate.part.0 [smc]
Take the socket reference while conns_lock still protects the tree entry.
The unregister path then cannot drop the last reference until termination
has finished using the socket.
Fixes: 69318b5215 ("net/smc: improve abnormal termination locking")
Cc: stable@vger.kernel.org
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Link: https://patch.msgid.link/20260723105454.87016-1-xuanqiang.luo@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
u32_change() copies the user-provided tc_u32_sel.offshift (unsigned char,
0-255) into the kernel knode object without bounds validation. When a
packet later hits u32_classify() with TC_U32_VAROFFSET set, it evaluates
`ntohs(offmask & *data) >> offshift` where the left operand is a 16-bit
value promoted to a 32-bit int. Any offshift >= 32 is undefined behavior
per C11 6.5.7p3, triggerable by an unprivileged user via user/network
namespaces.
UBSAN: shift-out-of-bounds in net/sched/cls_u32.c:236:43
shift exponent 32 is too large for 32-bit type int
Fix this by rejecting offshift >= 16 during filter creation in
u32_change().
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: AutonomousCodeSecurity@microsoft.com
Link: https://lore.kernel.org/all/20260720034514.23053-1-blbllhy@gmail.com
Signed-off-by: Cen Zhang (Microsoft) <blbllhy@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260723044955.89471-1-blbllhy@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
mpls_getroute() builds the RTM_NEWROUTE reply to an RTM_GETROUTE
request by filling a struct rtmsg allocated from an skb whose data
area is not zeroed (alloc_skb(NLMSG_GOODSIZE, ...)). It sets every
field of the header except rtm_tos:
r = nlmsg_data(nlh);
r->rtm_family = AF_MPLS;
r->rtm_dst_len = 20;
r->rtm_src_len = 0;
r->rtm_table = RT_TABLE_MAIN;
r->rtm_type = RTN_UNICAST;
r->rtm_scope = RT_SCOPE_UNIVERSE;
r->rtm_protocol = rt->rt_protocol;
r->rtm_flags = 0;
struct rtmsg has no padding, so the one uninitialised byte rtm_tos
(offset 3) is copied straight to user space on recvmsg(), leaking a
byte of uninitialised heap memory. This is in contrast to
mpls_dump_route(), which fills the very same header and does set
rtm_tos = 0.
Initialize rtm_tos to 0, matching mpls_dump_route().
Reproduced with KMSAN by adding an MPLS route and issuing a
non-RTM_F_FIB_MATCH RTM_GETROUTE for its label:
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x36c/0x33f0
_copy_to_iter+0x36c/0x33f0
__skb_datagram_iter+0x196/0x12c0
skb_copy_datagram_iter+0x5b/0x210
netlink_recvmsg+0x37b/0xef0
...
Uninit was created at:
__alloc_skb+0x8ca/0x10e0
mpls_getroute+0x1280/0x3a40
rtnetlink_rcv_msg+0x1138/0x15a0
...
Byte 19 of 64 is uninitialized
(byte 19 = nlmsghdr(16) + rtmsg offset 3 = rtm_tos)
Fixes: 397fc9e5ce ("mpls: route get support")
Signed-off-by: Yehyeong Lee <yhlee@isslab.korea.ac.kr>
Link: https://patch.msgid.link/20260723010830.289917-1-yhlee@isslab.korea.ac.kr
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
fou_create() publishes struct fou through sk_user_data before adding the
new FOU port to the per-netns list. If fou_add_to_port_list() fails,
the error path frees fou while it is still reachable through
sk_user_data. A concurrent receive can then dereference the freed
object in fou_from_sock().
This ordering issue was previously noted in the linked discussion.
The failure is reachable when local port 0 is requested. Each socket
binds to a different ephemeral port, but fou_cfg_cmp() compares the
requested port 0 and reports -EALREADY once an entry already exists.
Release the tunnel socket before freeing fou so sk_user_data is cleared
first, and defer reclamation with kfree_rcu() to protect concurrent RCU
readers. This matches the lifetime handling in fou_release().
Fixes: 23461551c0 ("fou: Support for foo-over-udp RX path")
Suggested-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://lore.kernel.org/netdev/20260502031401.3557229-12-kuniyu@google.com/
Cc: stable@vger.kernel.org
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Link: https://patch.msgid.link/20260722083858.182506-1-xuanqiang.luo@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
sctp_assoc_add_peer() increments the association's 16-bit transport_count
for every new unique peer. Adding the 65,536th transport wraps the count to
zero.
SCTP sock_diag uses transport_count to reserve the INET_DIAG_PEERS payload,
then copies one sockaddr_storage for every entry in transport_addr_list.
After the wrap, a diagnostic dump reserves an empty payload and writes
8 MiB of peer addresses past the skb tail.
Reject a new unique peer when transport_count has reached U16_MAX. Perform
the check after the existing-peer lookup so a duplicate address continues
to return its existing transport at the limit.
Fixes: 8f840e47f1 ("sctp: add the sctp_diag.c file")
Cc: stable@vger.kernel.org
Signed-off-by: Asim Viladi Oglu Manizada <manizada@pm.me>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20260725032053.521705-1-manizada@pm.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sctp_unpack_cookie() skips cookie expiration checks whenever an
association already exists. This is broader than the exception in
RFC 9260 Section 5.2.4.
For an existing association, Section 5.2.4 permits an expired State
Cookie only when both Verification Tags in the cookie match the current
association. Otherwise, the packet SHOULD be discarded and a Stale
Cookie ERROR MUST be sent.
The broad check lets an expired Action A restart cookie reach
sctp_sf_do_dupcook_a(). In a runtime test with the default 60 second
cookie lifetime, replaying such a cookie after 65 seconds returned a
COOKIE-ACK and restarted the association.
Check cookie expiration unless both Verification Tags match. This
preserves the Action D exception for a lost COOKIE ACK while rejecting
expired cookies in all other cases.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Yuxiang Yang <yangyx22@mails.tsinghua.edu.cn>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20260723225623.2658868-1-yangyx22@mails.tsinghua.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
br_multicast_leave_group() iterates mp->ports with pp = &p->next in
its fast-leave path. After br_multicast_del_pg() removes p,
continuing the loop advances pp through the deleted entry.
If multicast-to-unicast was enabled, the bridge can hold multiple port
groups for the same port and group with different source MAC
addresses. Once multicast-to-unicast is disabled,
br_port_group_equal() matches those entries by port only. A fast leave
can then delete one entry and continue from its stale next pointer,
leaving mp->ports pointing at a deleted port group.
Fast leave only needs to remove one matching port group. Break after
br_multicast_del_pg() so the loop stops before dereferencing the
removed entry.
Fixes: 6db6f0eae6 ("bridge: multicast to unicast")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Zhiling Zou <zhilinz@nebusec.ai>
Signed-off-by: Ren Wei <enjou1224z@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/1cf0898872ef7c72d5f4c0304414a192c6dac591.1784707712.git.zhilinz@nebusec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fib6_rule_suppress() drops a suppressed route with ip6_rt_put_flags(),
but leaves res->rt6 pointing at the released rt6_info.
If no later rule supplies a replacement, fib6_rule_lookup() still sees
res.rt6 and returns that stale dst to its caller. A suppressing rule can
therefore leak a released route back to rt6_lookup(), and the next put
hits rcuref_put_slowpath() from dst_release().
Clear res->rt6 when suppressing the route so suppressed lookups fall
through to the null dst instead of reusing the released one.
Fixes: cdef485217 ("ipv6: fix memory leak in fib6_rule_suppress")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Zhiling Zou <zhilinz@nebusec.ai>
Signed-off-by: Ren Wei <enjou1224z@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/4b8acb7787d54e440155585dd32ebdf0bef7d122.1784710966.git.zhilinz@nebusec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
TIPC socket tracepoints dump queue state through tipc_sk_dump(). Most
queue-dump callsites already serialize that walk under the socket lock or
sk->sk_lock.slock, but tipc_poll() calls trace_tipc_sk_poll(...,
TIPC_DUMP_ALL, ...) without holding either lock.
That lets the poll trace path reach tipc_list_dump() and backlog head/tail
dumping while another context dequeues and frees an skb, leaving the trace
helper dereferencing a stale queue entry.
Stop the unlocked poll trace site from requesting queue dumps. Other queue
dump trace callsites keep their existing output under the locking they
already provide, while poll still emits the event itself without walking
live queue members from an unlocked context.
Fixes: b4b9771bcb ("tipc: enable tracepoints in tipc")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Zihan Xi <zihanx@nebusec.ai>
Signed-off-by: Ren Wei <enjou1224z@gmail.com>
Reviewed-by: Tung Nguyen <tung.quang.nguyen@est.tech>
Link: https://patch.msgid.link/f8119abd5e5ecc400597de667ae9d39656de56d0.1784794294.git.zihanx@nebusec.ai
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry
under memory pressure or tree size caps, redirect handlers previously fell
back to sending un-rate-limited ICMP/NDISC Redirect messages.
In IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL.
In IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into
inet_peer_xrlim_allow(), which returned true when peer == NULL.
Because ICMP/NDISC Redirects are not part of the default global rate limit
mask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates
an un-rate-limited ICMP packet storm.
Fix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and
ndisc_send_redirect() when peer is NULL.
Fixes: 92d8682926 ("inetpeer: Move ICMP rate limiting state into inet_peer entries.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260724072901.1633601-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS fixes for net
The following batch contains Netfilter/IPVS fixes for net. This batch
includes a mix of IPVS follow ups related to Sashiko reports, as well as
crash fixes for connection tracking expectation, helpers, ipset and
nf_tables mostly for old bugs. This also includes a fix for the
flowtable tunnel selftest.
1) Use s32 instead of s16 to calculate the remaining payload containing
SIP messages, otherwise underflow is possible allowing out-of-bound
memory access beyond the skb->data area. From Xiang Mei.
2) Fix the counter check in the flowtable selftest for tunnels, from
Lorenzo Bianconi.
3) Add and use nf_ct_expect_related_pair() to add the RTP and RTCP
expectations under the expectation lock, this is required by the SIP
and H.323 NAT helpers. This fixes a possible reinsertion of an
expectation with the DEAD flag set on while looping to find
consecutive ports.
4) Fix ipset UaF during table resize by blocking comment updates on
kernel-side adds. From David Lee.
5) Do not propagate the IP_VS_CONN_F_ONE_PACKET flag when using IPVS
state synchronization, otherwise reaching stale freed from
ip_vs_conn struct is possible, Zhiling Zou.
6) Adjust the hn1 hash node when the forwarding method changes between
MASQ and non-MASQ for an already hashed connection. This can leave
stale hash nodes pointing to a freed struct ip_vs_conn and trigger
UaF while reading /proc/net/ip_vs_conn. From Julian Anastasov.
7) nft_object rhltable needs to be per table, just like chain rhltable,
otherwise UaF from object lookup path while netns is being released.
There is also the nlevent path that can reach stale objects. Placing
this rhltable under the table hierarchy fixes this issue.
8) Reject invalid combined usage of hashlimit tables with and without
XT_HASHLIMIT_RATE_MATCH flag mode, otherwise access to uninitialized
.burst field of dsthash_ent is possible.
9) Fix checksum validations in IPVS performed from LOCAL_IN,
from Julian Anastasov.
10) Fix incorrect packet offset to layer 4 protocol in IPVS, uncovered
by Sashiko, from Julian Anastasov.
11) Skip the mangling of ICMP replies for non-first fragments, also
reported by Sashiko. Also from Julian.
12) Clear ip_vs_conn flags under the spinlock to fix a possible data
race. From Julian Anastasov.
13) Fix incorrect calculation of the payload bitmask in the nf_tables
hardware offload support, leading to UBSAN splat. From Xiang Mei.
* tag 'nf-26-07-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nft_payload: fix mask build for partial field offload
ipvs: clear the nfct flag under lock
ipvs: do not mangle ICMP replies for non-first fragments
ipvs: fix places with wrong packet offsets
ipvs: fix the checksum validations
netfilter: xt_hashlimit: validate hashtable supports XT_HASHLIMIT_RATE_MATCH
netfilter: nf_tables: make nft_object rhltable per table
ipvs: adjust double hashing when fwd method changes
ipvs: do not propagate one-packet flag to synced conns
netfilter: ipset: do not update comments from kernel-side hash adds
netfilter: nf_conntrack_expect: add and use nf_ct_expect_related_pair()
selftests: netfilter: nft_flowtable.sh: fix offload counter verification for tunnel tests
netfilter: nf_conntrack_sip: widen NAT rewrite delta to s32 in sip_help_tcp()
====================
Link: https://patch.msgid.link/20260723163910.274695-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A frag_list skb can reach veth with data_len set but nr_frags zero.
veth_convert_skb_to_xdp_buff() only converts skbs that are shared,
locked, have frags[], or do not have enough headroom. It later uses
skb_is_nonlinear() to decide whether to set XDP_FLAGS_HAS_FRAGS and
xdp_frags_size.
That exposes frag_list data to XDP as if it were stored in frags[], but
frags[] is empty. AF_XDP copy mode can then trust the bogus XDP fragment
metadata, walk an empty fragment entry, and crash in memcpy() from
__xsk_rcv().
Route non-linear skbs through skb_pp_cow_data() before exposing them to
XDP, and only advertise XDP frags when the resulting skb has frags[].
skb_copy_bits() already handles frag_list input, and skb_pp_cow_data()
builds frags[] output with skb_add_rx_frag(), which is the
representation XDP multi-buffer expects.
Fixes: 718a18a0c8 ("veth: Rework veth_xdp_rcv_skb in order to accept non-linear skb")
Cc: stable@vger.kernel.org
Signed-off-by: Matt Fleming <mfleming@cloudflare.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@toke.dk>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260722191925.2192070-1-matt@readmodwrite.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pktgen_change_name() replaces pkt_dev->entry while holding t->if_lock.
pktgen_remove_device() removes the same entry before
_rem_dev_from_if_list() takes that lock.
This allows the following interleaving:
CPU 0 (NETDEV_CHANGENAME) CPU 1 (kpktgend)
if_lock(t)
proc_remove(pkt_dev->entry)
proc_remove(pkt_dev->entry)
pkt_dev->entry = proc_create_data(...)
if_unlock(t)
The kthread can pass the stale proc_dir_entry to proc_remove() after the
rename path has freed it. A reproducer with a widened race window reports:
BUG: KASAN: slab-use-after-free in proc_remove+0x78/0x80
Read of size 8 at addr ffff8881478fea70 by task kpktgend_0/67
Call Trace:
proc_remove+0x78/0x80
pktgen_remove_device.isra.0+0x11c/0x4c0
pktgen_thread_worker+0x1214/0x6bc0
kthread+0x2c6/0x3b0
Allocated by task 95:
__proc_create+0x204/0x790
proc_create_data+0x72/0xe0
pktgen_thread_write+0xd61/0x1510
Freed by task 28:
kmem_cache_free+0xcb/0x3d0
proc_free_inode+0x5b/0x80
rcu_core+0x50a/0x1850
The buggy address belongs to the object at ffff8881478fea00
which belongs to the cache proc_dir_entry of size 192
Move proc_remove() into the if_lock-protected list removal helper. Keep it
before list_del_rcu() to preserve the ordering required by add_device().
The rename path must then finish replacing the entry before removal, or
it observes that the device is no longer on the list.
Fixes: 39df232f1a ("[PKTGEN]: fix device name handling")
Cc: stable@vger.kernel.org
Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260719145740.2888967-1-nicoyip.dev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When cake_configure_rates() is called from the dequeue path with
rate_adjust=true, it only needs to update the rate parameters. The
loop that clears the unused tins is both unnecessary and harmful in
this path:
- cake_clear_tin() overwrites q->cur_tin and q->cur_flow, which are
actively used by cake_dequeue(), corrupting the dequeue state.
- iterating over the unused tins and their internal queues to purge
packets adds needless overhead to the hot path.
Skip the entire loop when rate_adjust is set, as neither
cake_clear_tin() nor the mtu_time update are needed when only the
rate changes.
The clearing loop runs on every rate adjustment from the dequeue path,
clearing (max_tins - cur_tins) tins each time, so the cost grows the
fewer tins the configured mode actually uses. Testing cake_mq over veth
(8 rx/tx queues, 2 Gbit limit) with flent's [1] rrul and tcp_nup tests and
32 TCP upstreams shows a large drop in loaded latency and a throughput
gain, restoring behaviour to pre-15c2715a5264 levels:
+------------+------+------+-------+-------+---------+
| kernel | mode | test | base | load | tput |
| | | | (ms) | (ms) | (Mbit) |
+------------+------+------+-------+-------+---------+
| net-next | be | rrul | 0.810 | 11.78 | 1469.67 |
| net-next | be | nup | 0.637 | 85.71 | 1243.15 |
| net-next | ds3 | rrul | 0.397 | 15.28 | 1770.06 |
| net-next | ds3 | nup | 0.351 | 15.98 | 1799.39 |
+------------+------+------+-------+-------+---------+
| patched | be | rrul | 0.092 | 0.56 | 1873.40 |
| patched | be | nup | 0.109 | 1.82 | 1869.12 |
| patched | ds3 | rrul | 0.097 | 0.98 | 1866.10 |
| patched | ds3 | nup | 0.101 | 0.51 | 1861.79 |
+------------+------+------+-------+-------+---------+
The same trend holds on real hardware (IPQ8074A, 4 rx/tx queues,
OpenWrt): in besteffort mode the tcp_nup loaded latency drops from
~470 ms to ~4 ms.
[1] https://flent.org
Fixes: 15c2715a52 ("net/sched: sch_cake: fixup cake_mq rate adjustment for diffserv config")
Signed-off-by: Jonas Köppeler <j.koeppeler@tu-berlin.de>
Tested-by: Mike Pham <mikepham4321@gmail.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20260720-sch_cake-skip-clearing-tins-v2-1-e6a8b0275c73@tu-berlin.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The zero-copy Tx batch parser stops when it encounters an invalid
descriptor. If this happens after one or more continuation descriptors,
the Tx consumer can be advanced past fragments that are neither submitted
to the driver nor returned to userspace through the completion ring.
A similar problem occurs when a packet exceeds xdp_zc_max_segs. The
descriptors consumed up to the limit are released without completion, and
the remaining continuation descriptors can subsequently be interpreted
as the beginning of another packet.
Parse Tx batches in packet units and distinguish descriptors belonging to
complete valid packets from descriptors consumed while draining an
invalid or oversized packet. Return the former to the driver and append
the latter to the CQ address area so userspace can reclaim their UMEM
frames.
Treat a standalone invalid descriptor as a one-descriptor reclaim-only
packet. Advancing the Tx-ring consumer releases the ring slot, but does
not by itself return ownership of the referenced UMEM frame to userspace.
Once draining starts, continue until the packet's end-of-packet
descriptor is consumed. Preserve the drain state on the socket when EOP
has not yet been supplied, so draining can continue during a later call.
Leave incomplete but otherwise valid packets on the Tx ring.
Shared-UMEM pools using multi-buffer Tx also need packet-framed parsing.
Walk their Tx sockets one packet at a time, preserving the existing
per-socket fairness scheme, instead of using the legacy one-descriptor
fallback. Keep that fallback for shared pools that do not use
multi-buffer Tx. Since the drain state is maintained per socket and both
the singular and shared paths can resume an interrupted drain, changing
the socket list from singular to shared requires no special bind-time
transition.
CQ entries are positional, and drivers may complete only part of the Tx
work returned by xsk_tx_peek_release_desc_batch(). Therefore, reclaim-only
entries cannot be published immediately when earlier driver-visible
descriptors are still outstanding.
Track the number of driver-visible CQ entries preceding the reclaim
entries. Let xsk_tx_completed() publish partial hardware Tx completions,
and publish the reclaim entries only after every earlier Tx descriptor
has completed. Complete a reclaim-only batch immediately when there is no
driver-visible work in front of it, and prevent another Tx batch from
being appended while reclaim entries remain pending.
Also cap batch processing by the size of the pool's temporary descriptor
array, as Tx rings belonging to sockets sharing a UMEM may have different
sizes.
This ensures that every invalid Tx descriptor consumed by the ZC batch
path is either submitted to the driver as part of a valid packet or
returned to userspace without violating CQ completion ordering.
Reviewed-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Fixes: cf24f5a5fe ("xsk: add support for AF_XDP multi-buffer on Tx path")
Link: https://patch.msgid.link/20260719135609.147823-5-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The temporary Tx descriptor array in an XSK buffer pool is currently
sized from the Tx ring of the socket that creates the pool.
This is insufficient for shared-UMEM Tx. A later socket may have a
larger Tx ring and submit a valid multi-buffer packet containing more
descriptors than the first socket's ring, while still remaining within
the device's xdp_zc_max_segs limit.
A packet-framed batch parser bounded by the temporary array cannot reach
the end-of-packet descriptor in that case. It leaves the packet on the
Tx ring and encounters the same packet on every subsequent attempt,
stalling Tx processing for that socket.
Size the temporary descriptor array to the larger of the first Tx ring
and the device's xdp_zc_max_segs capability. This keeps the array large
enough to inspect one maximum-sized valid packet. Larger shared Tx rings
do not require further resizing, as they can be processed over multiple
batches.
Following commit will actually address the data path side.
Fixes: d558196604 ("xsk: support ZC Tx multi-buffer in batch API")
Reviewed-by: Jason Xing <kernelxing@tencent.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260719135609.147823-4-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch is inspired by the check[1] from sashiko. It says when
overflow happens, the address of cq to be published is invalid.
Actually the severer thing is the whole process of publishing the
address of cq in this particular case is not right: it should truely
publish the address and advance the cached_prod in cq as long as it
reads descriptors from txq.
The following is the full analysis.
xsk_drop_skb() is called in three places, which all discard a partially
built multi-buffer skb:
1) xsk_build_skb() -EOVERFLOW error path: packet exceeds MAX_SKB_FRAGS
2) __xsk_generic_xmit() post-loop cleanup: an invalid descriptor in
the TX ring prevents the partial packet from completing
3) xsk_release(): socket close while xs->skb holds an incomplete packet
In all three cases, the TX descriptors for the already-processed frags
have been consumed from the TX ring (xskq_cons_release), and CQ slots
have been reserved. However, xsk_drop_skb() calls xsk_consume_skb()
which cancels the CQ reservations via xsk_cq_cancel_locked(). Since
the buffer addresses never appear in the completion queue, userspace
permanently loses track of these buffers.
Fix this by letting consume_skb() trigger the existing xsk_destruct_skb
destructor, which already submits buffer addresses to the CQ via
xsk_cq_submit_addr_locked().
Note that cancelling the descriptors back to the TX ring (via
xskq_cons_cancel_n) is not a appropriate option because an oversized
packet that always exceeds MAX_SKB_FRAGS would be retried indefinitely,
which is an obviously deadlock bug in the TX path.
Also move the desc->addr assignment in xsk_build_skb() above the
overflow check so that the current descriptor's address is recorded
before a potential -EOVERFLOW jump to free_err, consistent with the
zerocopy path in xsk_build_skb_zerocopy().
[1]: https://lore.kernel.org/all/20260425041726.85FB3C2BCB2@smtp.kernel.org/
Fixes: cf24f5a5fe ("xsk: add support for AF_XDP multi-buffer on Tx path")
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260719135609.147823-2-maciej.fijalkowski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit fd0a109a0f ("net, pidfs: prepare for handing out pidfds for
reaped sk->sk_peer_pid") inserted a prepare_peercred() call between err
= -EINVAL and the socket-state check in unix_listen(). Since
prepare_peercred() leaves err at 0 on success, listen() on an AF_UNIX
socket that is not in TCP_CLOSE or TCP_LISTEN state (e.g. one that is
already connected) now silently returns success without doing anything,
instead of failing with EINVAL as it did before.
Fixes: fd0a109a0f ("net, pidfs: prepare for handing out pidfds for reaped sk->sk_peer_pid")
Signed-off-by: John Ericson <mail@johnericson.me>
Link: https://patch.msgid.link/20260718182903.2295560-1-John.Ericson@Obsidian.Systems
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
nh_rt_cache_flush() walks nh->f6i_list during an RTNL-serialized nexthop
replace without holding nh->lock, racing the unlocked IPv6 route
add/delete that mutate the list under nh->lock and free fib6_info
entries (nh_rt_cache_flush() is inlined into rtm_new_nexthop()):
BUG: KASAN: slab-use-after-free in nh_rt_cache_flush (net/ipv4/nexthop.c:2243)
Read of size 8 at addr ffff888012953e18 by task exploit/146
nh_rt_cache_flush (net/ipv4/nexthop.c:2243)
replace_nexthop (net/ipv4/nexthop.c:2610)
rtm_new_nexthop (net/ipv4/nexthop.c:3323)
rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
Unlike the other f6i_list walks, this one bumps each route's sernum via
fib6_update_sernum_upto_root(), which needs tb6_lock; taking nh->lock
around it would invert the established tb6_lock -> nh->lock order and
deadlock. As the only purpose is to invalidate cached dsts, bump the
IPv6 sernum for the whole netns with rt_genid_bump_ipv6() instead,
mirroring the rt_cache_flush() already done for IPv4 just above.
Fixes: 081efd1832 ("ipv6: Protect nh->f6i_list with spinlock and flag.")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260722002951.2614721-2-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fib6_check_nh_list() and __nexthop_replace_notify() walk nh->f6i_list
during an RTNL-serialized nexthop replace without holding nh->lock. IPv6
RTM_NEWROUTE/RTM_DELROUTE run without RTNL and mutate that list under
nh->lock (fib6_add_rt2node_nh(), fib6_purge_rt()), so both walks race a
concurrent route delete that unlinks and frees a fib6_info:
BUG: KASAN: slab-use-after-free in rt6_fill_node.isra.0 (net/ipv6/route.c:5799)
Read of size 4 at addr ffff888014607e64 by task exploit/143
rt6_fill_node.isra.0 (net/ipv6/route.c:5799)
fib6_rt_update (net/ipv6/route.c:6412)
__nexthop_replace_notify (net/ipv4/nexthop.c:2542)
rtm_new_nexthop (net/ipv4/nexthop.c:2554)
rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
BUG: KASAN: slab-use-after-free in fib6_check_nh_list (net/ipv4/nexthop.c:1605)
Read of size 8 at addr ffff888014a7d068 by task exploit/142
fib6_check_nh_list (net/ipv4/nexthop.c:1605)
rtm_new_nexthop (net/ipv4/nexthop.c:2575)
rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)
Both walks only read the entries and take no tb6_lock, so protect them
with nh->lock; fib6_rt_update() uses gfp_any(), which returns GFP_ATOMIC
under the lock.
Fixes: 081efd1832 ("ipv6: Protect nh->f6i_list with spinlock and flag.")
Reported-by: AutonomousCodeSecurity@microsoft.com
Signed-off-by: Xiang Mei (Microsoft) <xmei5@asu.edu>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260722002951.2614721-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
rds_tcp_laddr_check() looks up a scoped IPv6 interface with
dev_get_by_index_rcu(), drops the RCU read-side lock, and only then
passes the bare struct net_device * into ipv6_chk_addr().
dev_get_by_index_rcu() only keeps the device alive within the same RCU
read-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can
free the net_device; ipv6_chk_addr() then dereferences the stale pointer
in __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading
freed memory.
Keep the RCU read-side lock held across the ipv6_chk_addr() call instead
of dropping it right after the lookup, so the device cannot be freed
while it is in use.
BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)
Read of size 8 at addr ffff8880106ec000 by task exploit/153
Call Trace:
...
kasan_report (mm/kasan/report.c:595)
__ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)
ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972)
rds_tcp_laddr_check (net/rds/tcp.c:370)
rds_bind (net/rds/bind.c:248)
__sys_bind (net/socket.c:1920)
__x64_sys_bind (net/socket.c:1956)
do_syscall_64 (arch/x86/entry/syscall_64.c:63)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
Fixes: eee2fa6ab3 ("rds: Changing IP address internal representation to struct in6_addr")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Allison Henderson <achender@kernel.org>
Link: https://patch.msgid.link/20260722210203.565803-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
