If either reconf or EPCS multi-link element (MLE) is contained in
a non-transmitted profile, the defragmentation routine is called
with a pointer to the defragmented copy, but the original elements.
This is incorrect for two reasons:
- if the original defragmentation was needed, it will not find the
correct data
- if the original frame is at a higher address, the parsing will
potentially overrun the heap data (though given the layout of
the buffers, only into the new defragmentation buffer, and then
it has to stop and fail once that's filled with copied data.
Fix it by tracking the container along with the pointer and in
doing so also unify the two almost identical defragmentation
routines.
Fixes: 4d70e9c548 ("wifi: mac80211: defragment reconfiguration MLE when parsing")
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Link: https://patch.msgid.link/20260508091031.8a6c34613178.I4de16ebbce2d27f2f8f98fc49949c7a376c2fe8d@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In client mode, the extended capabilities are handled by the kernel
looking at the association frame. When the supplicant installs the keys
it calls sta_apply_parameters and it doesn't include the extended
capabilities since those can't change after association.
As a result, we overrode the max_amsdu_subframes that we set after
association.
Check that the ext_capa coming from the user space is valid before
looking at it. If the ext_capa is NULL, it really means that the
extended capabilities are not changed (as opposed to cleared).
The default value for max_amsdu_subframes is 0, which means there is no
limit. This value is valid and in case the association response frame
does not have extended capabilities, this is the value we should use.
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221079
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20260513170623.828dbb58c782.Ifd2bfc190c26140e919127adb02ffddd7b551499@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
IEEE80211_MLE_STA_EPCS_CONTROL_LINK_ID is 0x000f, so link_id extracted
from a PRIO_ACCESS ML element PER_STA_PROFILE subelement can be 0..15.
sdata->link[] has IEEE80211_MLD_MAX_NUM_LINKS (15) entries (indices 0..14),
making index 15 out-of-bounds.
A connected WiFi 7 AP can trigger this by sending an EPCS Enable Response
action frame with a PER_STA_PROFILE subelement where link_id = 15. The
unsolicited-notification path (dialog_token = 0) is reachable any time
EPCS is already enabled, without any prior client request.
sdata->link[15] reads into the first word of sdata->activate_links_work
(a wiphy_work whose embedded list_head is non-NULL after INIT_LIST_HEAD),
so the NULL check on the result does not catch the invalid access. The
garbage pointer is then passed to ieee80211_sta_wmm_params(), which
dereferences link->sdata and crashes the kernel.
The same class of bug was fixed for ieee80211_ml_reconfiguration() by
commit 162d331d83 ("wifi: mac80211: bounds-check link_id in
ieee80211_ml_reconfiguration").
Fixes: de86c5f608 ("wifi: mac80211: Add support for EPCS configuration")
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
Link: https://patch.msgid.link/20260515102908.1653088-1-hossu.alexandru@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
cfg80211_merge_profile() reassembles a Multi-BSSID non-transmitted BSS
profile that has been split across multiple consecutive MBSSID elements.
Its while-loop calls
cfg80211_get_profile_continuation(ie, ielen, mbssid_elem, sub_elem)
but never advances mbssid_elem or sub_elem inside the body. Each
iteration therefore searches for a continuation that follows the same
fixed pair; the helper returns the same next_mbssid; and the same
next_sub bytes are memcpy()'d into merged_ie at a growing offset until
the buffer fills.
Advance both mbssid_elem and sub_elem to the just-consumed continuation
so the next call to cfg80211_get_profile_continuation() searches for a
further continuation beyond it (or returns NULL when none exists).
A specially-crafted malicious beacon can take advantage of this bug
to cause the kernel to spend an excessive amount of time in
cfg80211_merge_profile (up to as much as 2ms per beacon received),
which could theoretically be abused in some way.
Cc: stable@vger.kernel.org
Fixes: fe806e4992 ("cfg80211: support profile split between elements")
Signed-off-by: John Walker <johnwalker0@gmail.com>
Link: https://patch.msgid.link/20260507230720.64783-1-johnwalker0@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If a socket is bound to a wildcard address, tcp_v[46]_connect()
updates it with a non-wildcard address based on the route lookup.
After bhash2 was introduced in the cited commit, we must call
inet_bhash2_update_saddr() to update the bhash2 entry as well.
If inet_bhash2_update_saddr() fails, we must release the refcount
for dst by ip_route_connect() or ip6_dst_lookup_flow().
While tcp_v4_connect() calls ip_rt_put() in the error path,
tcp_v6_connect() does not call dst_release().
Let's call dst_release() when inet_bhash2_update_saddr() fails
in tcp_v6_connect().
Fixes: 28044fc1d4 ("net: Add a bhash2 table hashed by port and address")
Reported-by: Damiano Melotti <melotti@google.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260506070443.1699879-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In smc_connect_work(), when the underlying TCP handshake fails, the error
code (rc) must be propagated to sk_err to ensure userspace can correctly
retrieve the error status via SO_ERROR. Currently, the code only handles
a restricted set of error codes (e.g., EPIPE, ECONNREFUSED). If other
errors occurs, such as EHOSTUNREACH, sk_err remains unset (zero).
This affects applications that rely on SO_ERROR to determine connect
outcome. For example, higher versions of Go's netpoller treats
SO_ERROR == 0 combined with a failed getpeername() as a spurious wakeup
and re-enters epoll_wait(). Under ET mode, no further edge will be
generated since the socket is already in a terminal state, causing the
connect to hang indefinitely or until a user-specified timeout, if one
is set.
Fixes: 50717a37db ("net/smc: nonblocking connect rework")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Link: https://patch.msgid.link/20260506014105.27093-1-alibuda@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When looking at the maximum RTO amongst the subflows, inactive subflows
were taken into account: that includes stale ones, and the initial one
if it has been already been closed.
Unusable subflows are now simply skipped. Stale ones are used as an
alternative: if there are only stale ones, to take their maximum RTO and
avoid to eventually fallback to net.mptcp.add_addr_timeout, which is set
to 2 minutes by default.
Fixes: 30549eebc4 ("mptcp: make ADD_ADDR retransmission timeout adaptive")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-7-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When an ADD_ADDR needs to be retransmitted and another one has already
been prepared -- e.g. multiple ADD_ADDRs have been sent in a row and
need to be retransmitted later -- this additional retransmission will
need to wait.
In this case, the timer was reset to TCP_RTO_MAX / 8, which is ~15
seconds. This delay is unnecessary long: it should just be rescheduled
at the next opportunity, e.g. after the retransmission timeout.
Without this modification, some issues can be seen from time to time in
the selftests when multiple ADD_ADDRs are sent, and the host takes time
to process them, e.g. the "signal addresses, ADD_ADDR timeout" MPTCP
Join selftest, especially with a debug kernel config.
Note that on older kernels, 'timeout' is not available. It should be
enough to replace it by one second (HZ).
Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-6-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(),
and released at the end.
If at that moment, it was the last reference being held, the sk would
not be freed. sock_put() should then be called instead of __sock_put().
But that's not enough: if it is the last reference, sock_put() will call
sk_free(), which will end up calling sk_stop_timer_sync() on the same
timer, and waiting indefinitely to finish. So it is needed to mark that
the timer is done at the end of the timer handler when it has not been
rescheduled, not to call sk_stop_timer_sync() on "itself".
Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-5-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer().
It should then be released in all cases at the end.
Some (unlikely) checks were returning directly instead of calling
sock_put() to decrease the refcount. Jump to a new 'exit' label to call
__sock_put() (which will become sock_put() in the next commit) to fix
this potential leak.
While at it, drop the '!msk' check which cannot happen because it is
never reset, and explicitly mark the remaining one as "unlikely".
Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-4-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When adding the ADD_ADDR to the list, the address including the IP, port
and ID are copied. On the other hand, when the endpoint corresponds to
the one from the initial subflow, the ID is set to 0, as specified by
the MPTCP protocol.
The issue is that the ID was reset after having copied the ID in the
ADD_ADDR entry. So the retransmission was done, but using a different ID
than the initial one.
Fixes: 8b8ed1b429 ("mptcp: pm: reuse ID 0 after delete and re-add")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-1-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tcp_child_process( .. child ...) currently calls sock_put(child).
Unfortunately @child (named @nsk in callers) can be used after
this point to send a RST packet.
To fix this UAF, I remove the sock_put() from tcp_child_process()
and let the callers handle this after it is safe.
Remove @rsk variable in tcp_v4_do_rcv() and change tcp_v6_do_rcv()
so that both functions look the same.
Fixes: cfb6eeb4c8 ("[TCP]: MD5 Signature Option (RFC2385) support.")
Reported-by: Damiano Melotti <melotti@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260505153927.3435532-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When performing a lockless lookup over the inet_peer rbtree,
if a matching node is found, inet_getpeer() returns it immediately
without validating the seqlock sequence.
This missing check introduces a race condition:
Trigger Path: When a host receives an incoming fragmented IPv4 packet,
ip4_frag_init() (in net/ipv4/ip_fragment.c) calls inet_getpeer_v4()
to track the peer.
The Race: If the packet is from a new source IP, CPU A acquires the
write_seqlock, allocates a new inet_peer node (p), sets its IP address
(daddr), and links it to the rbtree (rb_link_node).
Uninitialized Access: Due to the lack of memory barriers between
rb_link_node and the initialization of the rest of the struct
(like refcount_set(&p->refcnt, 1)), CPU A can make the node visible
to readers before its refcnt is initialized.
This is especially true on weakly-ordered architectures like ARM64
where the CPU can reorder the memory stores.
Lockless Reader: Concurrently, CPU B processes a second fragmented packet
from the same source IP. CPU B does a lockless lookup, finds the newly
inserted node, and returns it immediately.
Use-After-Free (UAF): CPU B reads p->refcnt as uninitialized garbage
(left over from previous kmalloc-128/192 allocations).
If the garbage is > 0, refcount_inc_not_zero(&p->refcnt) succeeds.
CPU A then executes refcount_set(&p->refcnt, 1), overwriting CPU B's increment.
When CPU B finishes with the fragment queue, it calls inet_putpeer(),
which drops the refcount to 0 and frees the node via RCU.
The node is now freed but remains linked in the rbtree,
resulting in a Use-After-Free in the rbtree.
Fixes: b145425f26 ("inetpeer: remove AVL implementation in favor of RB tree")
Reported-by: Damiano Melotti <melotti@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260505133233.3039575-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Steffen Klassert says:
====================
pull request (net): ipsec 2026-05-05
1. Fix an IPv6 encapsulation error path that leaked route references
when UDPv6 ESP decapsulation resolved to an error route.
From Yilin Zhu.
2. Fix AH with ESN on async crypto paths by accounting for the extra
high-order sequence number when reconstructing the temporary
authentication layout in the completion callbacks.
From Michael Bomarito.
3. Fix XFRM output so it does not overwrite already-correct inner header
pointers when a tunnel layer such as VXLAN has already saved them.
The fix comes with new selftests. From Cosmin Ratiu.
4. Add the missing native payload size entry for XFRM_MSG_MAPPING in the
compat translation path. From Ruijie Li.
5. Harden __xfrm_state_delete() against repeated or inconsistent unhashing
of state list nodes by keying the removal on actual list membership and
using delete-and-init helpers. From Michal Kosiorek.
6. Prevent ESP from decrypting shared splice-backed skb fragments in place
by marking UDP splice frags as shared and forcing copy-on-write in ESP
input when needed. From Kuan-Ting Chen.
* tag 'ipsec-2026-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
xfrm: esp: avoid in-place decrypt on shared skb frags
xfrm: defensively unhash xfrm_state lists in __xfrm_state_delete
xfrm: provide message size for XFRM_MSG_MAPPING
xfrm: Don't clobber inner headers when already set
tools/selftests: Add a VXLAN+IPsec traffic test
tools/selftests: Use a sensible timeout value for iperf3 client
xfrm: ah: account for ESN high bits in async callbacks
ipv6: xfrm6: release dst on error in xfrm6_rcv_encap()
====================
Link: https://patch.msgid.link/20260505132326.1362733-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit dbf666e4fc ("Bluetooth: HIDP: Fix possible UAF") made
hidp_session_remove() drop the L2CAP reference and set
session->conn = NULL once the session is considered removed, and
added a bare if (session->conn) guard around the kthread-exit
l2cap_unregister_user() call in hidp_session_thread(). The sibling
ioctl site in hidp_connection_del() still reads session->conn
unlocked and unguarded, and the kthread-exit guard itself is a
lockless double-read.
hidp_session_find() drops hidp_session_sem before returning, so
hidp_session_remove() can null session->conn between the lookup and
the call in hidp_connection_del(). Worse, since commit 752a6c9596
("Bluetooth: L2CAP: Fix use-after-free in l2cap_unregister_user")
takes mutex_lock(&conn->lock) inside l2cap_unregister_user(), a
stale non-NULL snapshot also UAFs on conn->lock. v1 only added an
if (session->conn) guard at the ioctl site, which doesn't address
either race; Luiz suggested snapshotting session->conn under the
sem and clearing it before the call.
Taking hidp_session_sem across l2cap_unregister_user() would be
wrong: l2cap_conn_del() already establishes the lock order
conn->lock -> hidp_session_sem
via l2cap_unregister_all_users() -> user->remove ==
hidp_session_remove(), so taking hidp_session_sem before conn->lock
would AB/BA deadlock.
Factor a helper hidp_session_unregister_conn() that under
down_write(&hidp_session_sem) snapshots session->conn and clears
the member, then outside the sem calls l2cap_unregister_user() and
l2cap_conn_put() on the snapshot. Call it from both
hidp_connection_del() and hidp_session_thread()'s exit path. At
most one consumer wins the write-sem; later callers observe
session->conn == NULL and skip the unregister and put, so the
reference hidp_session_new() took via l2cap_conn_get() is consumed
exactly once. session_free() already tolerates a NULL session->conn.
Fixes: dbf666e4fc ("Bluetooth: HIDP: Fix possible UAF")
Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/all/20260422011437.176643-1-michael.bommarito@gmail.com/
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
hci_le_big_sync_established_evt() currently does:
conn->num_bis = 0;
memset(conn->bis, 0, sizeof(conn->num_bis));
sizeof(conn->num_bis) is wrong - it would make sense to either use
conn->num_bis (before setting that to 0) or sizeof(conn->bis).
Fix it by using sizeof(conn->bis), the least intrusive change.
Luckily, nothing actually depends on this memset() working properly:
Nothing seems to ever read from conn->bis beyond conn->num_bis, and when
conn->num_bis is increased, the corresponding elements of conn->bis are
initialized. So I think this line could also just be removed.
This is a purely theoretical fix and should have no impact on actual
behavior.
Fixes: 42ecf19471 ("Bluetooth: ISO: Do not emit LE BIG Create Sync if previous is pending")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
rfcomm_recv_data() treats the first payload byte as a credit field when
the UIH frame carries PF and credit-based flow control is enabled.
After the header has been stripped, the PF/CFC path consumes that byte
with a direct skb->data dereference followed by skb_pull(). A malformed
short frame can reach this path without a byte available.
Use skb_pull_data() so the length check and pull happen together before
the returned credit byte is consumed.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Several iso_pi(sk) fields (qos, qos_user_set, bc_sid, base, base_len,
sync_handle, bc_num_bis) are written under lock_sock in
iso_sock_setsockopt() and iso_sock_bind(), but read and written under
hci_dev_lock only in two other paths:
- iso_connect_bis() / iso_connect_cis(), invoked from connect(2),
read qos/base/bc_sid and reset qos to default_qos on the
qos_user_set validation failure -- all without lock_sock.
- iso_connect_ind(), invoked from hci_rx_work, writes sync_handle,
bc_sid, qos.bcast.encryption, bc_num_bis, base and base_len on
PA_SYNC_ESTABLISHED / PAST_RECEIVED / BIG_INFO_ADV_REPORT /
PER_ADV_REPORT events. The BIG_INFO handler additionally passes
&iso_pi(sk)->qos together with sync_handle / bc_num_bis / bc_bis
to hci_conn_big_create_sync() while setsockopt may be mutating
them.
Acquire lock_sock around the affected accesses in both paths.
The locking order hci_dev_lock -> lock_sock matches the existing
iso_conn_big_sync() precedent, whose comment documents the same
requirement for hci_conn_big_create_sync(). The HCI connect/bind
helpers do not wait for command completion -- they enqueue work via
hci_cmd_sync_queue{,_once}() / hci_le_create_cis_pending() and
return -- so the added hold time is comparable to iso_conn_big_sync().
KCSAN report:
BUG: KCSAN: data-race in iso_connect_cis / iso_sock_setsockopt
read to 0xffffa3ae8ce3cdc8 of 1 bytes by task 335 on cpu 0:
iso_connect_cis+0x49f/0xa20
iso_sock_connect+0x60e/0xb40
__sys_connect_file+0xbd/0xe0
__sys_connect+0xe0/0x110
__x64_sys_connect+0x40/0x50
x64_sys_call+0xcad/0x1c60
do_syscall_64+0x133/0x590
entry_SYSCALL_64_after_hwframe+0x77/0x7f
write to 0xffffa3ae8ce3cdc8 of 60 bytes by task 334 on cpu 1:
iso_sock_setsockopt+0x69a/0x930
do_sock_setsockopt+0xc3/0x170
__sys_setsockopt+0xd1/0x130
__x64_sys_setsockopt+0x64/0x80
x64_sys_call+0x1547/0x1c60
do_syscall_64+0x133/0x590
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 334 Comm: iso_setup_race Not tainted 7.0.0-10949-g8541d8f725c6 #44 PREEMPT(lazy)
The iso_connect_ind() races were found by inspection.
Fixes: ccf74f2390 ("Bluetooth: Add BTPROTO_ISO socket type")
Signed-off-by: SeungJu Cheon <suunj1331@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
iso_sock_connect() copies the destination address into
iso_pi(sk)->dst under lock_sock, then releases the lock and reads
it back with bacmp() to decide between the CIS and BIS connect
paths:
lock_sock(sk);
bacpy(&iso_pi(sk)->dst, &sa->iso_bdaddr);
iso_pi(sk)->dst_type = sa->iso_bdaddr_type;
release_sock(sk);
if (bacmp(&iso_pi(sk)->dst, BDADDR_ANY)) // <- no lock held
This read after release_sock() races with any concurrent write to
iso_pi(sk)->dst on the same socket.
Fix by reading the destination address directly from the local
sockaddr argument (sa->iso_bdaddr) instead of iso_pi(sk)->dst.
Since sa is a function-local argument, reading it requires no
locking and avoids the race.
This patch addresses only the bacmp() race in iso_sock_connect();
other unprotected iso_pi(sk) accesses are fixed separately in the
next patch.
KCSAN report:
BUG: KCSAN: data-race in memcmp+0x39/0xb0
race at unknown origin, with read to 0xffff8f96ea66dde3 of 1 bytes by task 549 on cpu 1:
memcmp+0x39/0xb0
iso_sock_connect+0x275/0xb40
__sys_connect_file+0xbd/0xe0
__sys_connect+0xe0/0x110
__x64_sys_connect+0x40/0x50
x64_sys_call+0xcad/0x1c60
do_syscall_64+0x133/0x590
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x00 -> 0xee
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 549 Comm: iso_race_combin Not tainted 7.0.0-08391-g1d51b370a0f8 #40 PREEMPT(lazy)
Fixes: ccf74f2390 ("Bluetooth: Add BTPROTO_ISO socket type")
Signed-off-by: SeungJu Cheon <suunj1331@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
sk deref in sco_conn_ready must be done either under conn->lock, or
holding a refcount, to avoid concurrent close. conn->sk and parent sk is
currently accessed without either, and without checking parent->sk_state:
[Task 1] [Task 2]
sco_sock_release
sco_conn_ready
sk = conn->sk
lock_sock(sk)
conn->sk = NULL
lock_sock(sk)
release_sock(sk)
sco_sock_kill(sk)
UAF on sk deref
and similarly for access to sco_get_sock_listen() return value.
Fix possible UAF by holding sk refcount in sco_conn_ready() and making
sco_get_sock_listen() increase refcount. Also recheck after lock_sock
that the socket is still valid. Adjust conn->sk locking so it's
protected also by lock_sock() of the associated socket if any.
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>
Add the same NULL guard already present in
l2cap_sock_resume_cb() and l2cap_sock_ready_cb().
Fixes: 80808e431e ("Bluetooth: Add l2cap_chan_ops abstraction")
Cc: stable@kernel.org
Signed-off-by: Siwei Zhang <oss@fourdim.xyz>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Add the same NULL guard already present in
l2cap_sock_resume_cb() and l2cap_sock_ready_cb().
Fixes: 8d836d71e2 ("Bluetooth: Access sk_sndtimeo indirectly in l2cap_core.c")
Cc: stable@kernel.org
Signed-off-by: Siwei Zhang <oss@fourdim.xyz>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Add the same NULL guard already present in
l2cap_sock_resume_cb() and l2cap_sock_ready_cb().
Fixes: 89bc500e41 ("Bluetooth: Add state tracking to struct l2cap_chan")
Cc: stable@kernel.org
Signed-off-by: Siwei Zhang <oss@fourdim.xyz>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
When a BLE peripheral sends an L2CAP Connection Parameter Update Request
the processing path is:
process_pending_rx() [takes conn->lock]
l2cap_le_sig_channel()
l2cap_conn_param_update_req()
hci_le_conn_update() [takes hdev->lock]
Meanwhile other code paths take the locks in the opposite order:
l2cap_chan_connect() [takes hdev->lock]
...
mutex_lock(&conn->lock)
l2cap_conn_ready() [hdev->lock via hci_cb_list_lock]
...
mutex_lock(&conn->lock)
This is a classic AB/BA deadlock which lockdep reports as a circular
locking dependency when connecting a BLE MIDI keyboard (Carry-On FC-49).
Fix this by making hci_le_conn_update() defer the HCI command through
hci_cmd_sync_queue() so it no longer needs to take hdev->lock in the
caller context. The sync callback uses __hci_cmd_sync_status_sk() to
wait for the HCI_EV_LE_CONN_UPDATE_COMPLETE event, then updates the
stored connection parameters (hci_conn_params) and notifies userspace
(mgmt_new_conn_param) only after the controller has confirmed the update.
A reference on hci_conn is held via hci_conn_get()/hci_conn_put() for
the lifetime of the queued work to prevent use-after-free, and
hci_conn_valid() is checked before proceeding in case the connection was
removed while the work was pending. The hci_dev_lock is held across
hci_conn_valid() and all conn field accesses to prevent a concurrent
disconnect from invalidating the connection mid-use.
Fixes: f044eb0524 ("Bluetooth: Store latency and supervision timeout in connection params")
Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The L2CAP specification states that if more than one channel is being
reconfigured, the MPS shall not be decreased. The current check has
two issues:
1) The comparison uses >= (greater-than-or-equal), which incorrectly
rejects reconfiguration requests where the MPS stays the same.
Since the spec says MPS "shall be greater than or equal to the
current MPS", only a strict decrease (remote_mps > mps) should be
rejected. Keeping the same MPS is valid.
2) The multi-channel guard uses `&& i` (loop index) to approximate
"more than one channel", but this incorrectly allows MPS decrease
for the first channel (i==0) even when multiple channels are being
reconfigured. Replace with `&& num_scid > 1` which correctly
checks whether the request covers more than one channel.
Fixes: 7accb1c432 ("Bluetooth: L2CAP: Fix invalid response to L2CAP_ECRED_RECONF_REQ")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
In bnep_rx_frame(), the BNEP_FILTER_NET_TYPE_SET and
BNEP_FILTER_MULTI_ADDR_SET extension header parsing has two bugs:
1) The 2-byte length field is read with *(u16 *)(skb->data + 1), which
performs a native-endian read. The BNEP protocol specifies this field
in big-endian (network byte order), and the same file correctly uses
get_unaligned_be16() for the identical fields in
bnep_ctrl_set_netfilter() and bnep_ctrl_set_mcfilter().
2) The length is multiplied by 2, but unlike BNEP_SETUP_CONN_REQ where
the length byte counts UUID pairs (requiring * 2 for two UUIDs per
entry), the filter extension length field already represents the total
data size in bytes. This is confirmed by bnep_ctrl_set_netfilter()
which reads the same field as a byte count and divides by 4 to get
the number of filter entries.
The bogus * 2 means skb_pull advances twice as far as it should,
either dropping valid data from the next header or causing the pull
to fail entirely when the doubled length exceeds the remaining skb.
Fix by splitting the pull into two steps: first use skb_pull_data() to
safely pull and validate the 3-byte fixed header (ctrl type + length),
then pull the variable-length data using the properly decoded length.
Fixes: bf8b9a9cb7 ("Bluetooth: bnep: Add support to extended headers of control frames")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
hci_le_create_big_complete_evt() iterates over BT_BOUND connections for
a BIG handle using a while loop, accessing ev->bis_handle[i++] on each
iteration. However, there is no check that i stays within ev->num_bis
before the array access.
When a controller sends a LE_Create_BIG_Complete event with fewer
bis_handle entries than there are BT_BOUND connections for that BIG,
or with num_bis=0, the loop reads beyond the valid bis_handle[] flex
array into adjacent heap memory. Since the out-of-bounds values
typically exceed HCI_CONN_HANDLE_MAX (0x0EFF), hci_conn_set_handle()
rejects them and the connection remains in BT_BOUND state. The same
connection is then found again by hci_conn_hash_lookup_big_state(),
creating an infinite loop with hci_dev_lock held.
Fix this by terminating the BIG if in case not all BIS could be setup
properly.
Fixes: a0bfde167b ("Bluetooth: ISO: Add support for connecting multiple BISes")
Cc: stable@vger.kernel.org
Signed-off-by: ZhiTao Ou <hkbinbinbin@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Add hci_conn_valid() check in create_big_sync() to detect stale
connections before proceeding with BIG creation. Handle the
resulting -ECANCELED in create_big_complete() and re-validate the
connection under hci_dev_lock() before dereferencing, matching the
pattern used by create_le_conn_complete() and create_pa_complete().
Keep the hci_conn object alive across the async boundary by taking
a reference via hci_conn_get() when queueing create_big_sync(), and
dropping it in the completion callback. The refcount and the lock
are complementary: the refcount keeps the object allocated, while
hci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on
hdev->conn_hash, as required by hci_conn_del().
hci_conn_put() is called outside hci_dev_unlock() so the final put
(which resolves to kfree() via bt_link_release) does not run under
hdev->lock, though the release path would be safe either way.
Without this, create_big_complete() would unconditionally
dereference the conn pointer on error, causing a use-after-free
via hci_connect_cfm() and hci_conn_del().
Fixes: eca0ae4aea ("Bluetooth: Add initial implementation of BIS connections")
Cc: stable@vger.kernel.org
Co-developed-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
sco_conn_ready calls sleeping functions under conn->lock spinlock.
The critical section can be reduced: conn->hcon is modified only with
hdev->lock held. It is guaranteed to be held in sco_conn_ready, so
conn->lock is not needed to guard it.
Move taking conn->lock after lock_sock(parent). This also follows the
lock ordering lock_sock() > conn->lock elsewhere in the file.
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>
Johannes Berg says:
====================
Quite a number of fixes now:
- mac80211
- remove HT NSS validation to work with broken APs
(with a kunit fix now)
- remove 'static' that could cause races
- check station link lookup before further processing
- fix use-after-free due to delete in list iteration
- remove AP station on assoc failures to fix crashes
- ath12k
- fix OF node refcount imbalance
- fix queue flush ("REO update") in MLO
- fix RCU assert
- ath12k:
- fix Kconfig with POWER_SEQUENCING
- fix WMI buffer leaks on error conditions
- don't use uninitialized stack data when processing RSSI events
- fix logic for determining the peer ID in the RX path
- ath5k: fix a potential stack buffer overwrite
- rsi: fix thread lifetime race
- brcmfmac: fix potential UAF
- nl80211:
- stricter permissions/checks for PMK and netns
- fix netlink policy vs. code type confusion
- cw1200: revert a broken locking change
- various fixes to not trust values from firmware
* tag 'wireless-2026-05-06' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless: (25 commits)
wifi: nl80211: re-check wiphy netns in nl80211_prepare_wdev_dump() continuation
wifi: nl80211: require CAP_NET_ADMIN over the target netns in SET_WIPHY_NETNS
wifi: nl80211: fix NL80211_PMSR_FTM_REQ_ATTR_FTMS_PER_BURST usage
wifi: mac80211: remove station if connection prep fails
wifi: mac80211: use safe list iteration in radar detect work
wifi: libertas: notify firmware load wait on disconnect
wifi: ath5k: do not access array OOB
wifi: ath12k: fix peer_id usage in normal RX path
wifi: ath12k: initialize RSSI dBm conversion event state
wifi: ath12k: fix leak in some ath12k_wmi_xxx() functions
wifi: cw1200: Revert "Fix locking in error paths"
wifi: mac80211: tests: mark HT check strict
wifi: rsi: fix kthread lifetime race between self-exit and external-stop
wifi: mac80211: drop stray 'static' from fast-RX rx_result
wifi: mac80211: check ieee80211_rx_data_set_link return in pubsta MLO path
wifi: nl80211: require admin perm on SET_PMK / DEL_PMK
wifi: libertas: fix integer underflow in process_cmdrequest()
wifi: b43legacy: enforce bounds check on firmware key index in RX path
wifi: b43: enforce bounds check on firmware key index in b43_rx()
wifi: brcmfmac: Fix potential use-after-free issue when stopping watchdog task
...
====================
Link: https://patch.msgid.link/20260506110325.219675-3-johannes@sipsolutions.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
NL80211_CMD_GET_SCAN is implemented as a multi-call dumpit. The first
invocation of nl80211_prepare_wdev_dump() validates the requested wdev
against the caller's netns via __cfg80211_wdev_from_attrs(). Subsequent
invocations look up the same wiphy by its global index and do not check
that the wiphy is still in the caller's netns.
Add the same filter to the continuation path. If the wiphy's netns no
longer matches the caller's, return -ENODEV and the netlink dump
machinery terminates the walk cleanly.
Signed-off-by: Maoyi Xie <maoyi.xie@ntu.edu.sg>
Link: https://patch.msgid.link/20260506064854.2207105-3-maoyixie.tju@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
NL80211_CMD_SET_WIPHY_NETNS dispatches with GENL_UNS_ADMIN_PERM, which
verifies that the caller has CAP_NET_ADMIN for the source netns. It
doesn't verify that the caller has CAP_NET_ADMIN over the target netns
selected by NL80211_ATTR_NETNS_FD or NL80211_ATTR_PID.
This diverges from the convention enforced in
net/core/rtnetlink.c::rtnl_get_net_ns_capable():
/* For now, the caller is required to have CAP_NET_ADMIN in
* the user namespace owning the target net ns.
*/
if (!sk_ns_capable(sk, net->user_ns, CAP_NET_ADMIN))
return ERR_PTR(-EACCES);
A user with CAP_NET_ADMIN in their own user namespace can therefore
push a wiphy into an arbitrary netns (including init_net) over which
they have no privilege.
Mirror the rtnetlink convention by requiring CAP_NET_ADMIN in the
target netns before calling cfg80211_switch_netns().
Signed-off-by: Maoyi Xie <maoyi.xie@ntu.edu.sg>
Link: https://patch.msgid.link/20260506064854.2207105-2-maoyixie.tju@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If connection preparation fails for MLO connections, then the
interface is completely reset to non-MLD. In this case, we must
not keep the station since it's related to the link of the vif
being removed. Delete an existing station. Any "new_sta" is
already being removed, so that doesn't need changes.
This fixes a use-after-free/double-free in debugfs if that's
enabled, because a vif going from MLD (and to MLD, but that's
not relevant here) recreates its entire debugfs.
Cc: stable@vger.kernel.org
Fixes: 81151ce462 ("wifi: mac80211: support MLO authentication/association with one link")
Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20260505151533.c4e52deb06ad.Iafe56cec7de8512626169496b134bce3a6c17010@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In copy mode TX, xsk_skb_destructor_set_addr() stores the 64-bit
descriptor address into skb_shinfo(skb)->destructor_arg (void *) via a
uintptr_t cast:
skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t)addr | 0x1UL);
On 32-bit architectures uintptr_t is 32 bits, so the upper 32 bits of
the descriptor address are silently dropped. In XDP_ZEROCOPY unaligned
mode the chunk offset is encoded in bits 48-63 of the descriptor
address (XSK_UNALIGNED_BUF_OFFSET_SHIFT = 48), meaning the offset is
lost entirely. The completion queue then returns a truncated address to
userspace, making buffer recycling impossible.
Fix this by handling the 32-bit case directly in
xsk_skb_destructor_set_addr(): when !CONFIG_64BIT, allocate an
xsk_addrs struct (the same path already used for multi-descriptor
SKBs) to store the full u64 address. The existing tagged-pointer logic
in xsk_skb_destructor_is_addr() stays unchanged: slab pointers returned
from kmem_cache_zalloc() are always word-aligned and therefore have
bit 0 clear, which correctly identifies them as a struct pointer
rather than an inline tagged address on every architecture.
Factor the shared kmem_cache_zalloc + destructor_arg assignment into
__xsk_addrs_alloc() and add a wrapper xsk_addrs_alloc() that handles
the inline-to-list upgrade (is_addr check + get_addr + num_descs = 1).
The three former open-coded kmem_cache_zalloc call sites now reduce to
a single call each.
Propagate the -ENOMEM from xsk_skb_destructor_set_addr() through
xsk_skb_init_misc() so the caller can clean up the skb via kfree_skb()
before skb->destructor is installed.
The overhead is one extra kmem_cache_zalloc per first descriptor on
32-bit only; 64-bit builds are completely unchanged.
Closes: https://lore.kernel.org/all/20260419045824.D9E5EC2BCAF@smtp.kernel.org/
Fixes: 0ebc27a4c6 ("xsk: avoid data corruption on cq descriptor number")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20260502200722.53960-9-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When xsk_build_skb() / xsk_build_skb_zerocopy() sees the first
continuation descriptor, it promotes destructor_arg from an inlined
address to a freshly allocated xsk_addrs (num_descs = 1). The counter
is bumped to >= 2 only at the very end of a successful build (by calling
xsk_inc_num_desc()).
If the build fails in between (e.g. alloc_page() returns NULL with
-EAGAIN, or the MAX_SKB_FRAGS overflow hits), we jump to free_err, skip
calling xsk_inc_num_desc() to increment num_descs and leave the half-built
skb attached to xs->skb for the app to retry. The skb now has
1) destructor_arg = a real xsk_addrs pointer,
2) num_descs = 1
If the app never retries and just close()s the socket, xsk_release()
calls xsk_drop_skb() -> xsk_consume_skb(), which decides whether to
free xsk_addrs by testing num_descs > 1:
if (unlikely(num_descs > 1))
kmem_cache_free(xsk_tx_generic_cache, destructor_arg);
Because num_descs is exactly 1 the branch is skipped and the
xsk_addrs object is leaked to the xsk_tx_generic_cache slab.
Fix it by directly testing if destructor_arg is still addr. Or else it
is modified and used to store the newly allocated memory from
xsk_tx_generic_cache regardless of increment of num_desc, which we
need to handle.
Closes: https://lore.kernel.org/all/20260419045824.D9E5EC2BCAF@smtp.kernel.org/
Fixes: 0ebc27a4c6 ("xsk: avoid data corruption on cq descriptor number")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20260502200722.53960-8-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Once xsk_skb_init_misc() has been called on an skb, its destructor is
set to xsk_destruct_skb(), which submits the descriptor address(es) to
the completion queue and advances the CQ producer. If such an skb is
subsequently freed via kfree_skb() along an error path - before the
skb has ever been handed to the driver - the destructor still runs and
submits a bogus, half-initialized address to the CQ.
Postpone the init phase when we believe the allocation of first frag is
successfully completed. Before this init, skb can be safely freed by
kfree_skb().
Closes: https://lore.kernel.org/all/20260419045822.843BFC2BCAF@smtp.kernel.org/
Fixes: c30d084960 ("xsk: avoid overwriting skb fields for multi-buffer traffic")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20260502200722.53960-6-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When xsk_build_skb() processes multi-buffer packets in copy mode, the
first descriptor stores data into the skb linear area without adding
any frags, so nr_frags stays at 0. The caller then sets xs->skb = skb
to accumulate subsequent descriptors.
If a continuation descriptor fails (e.g. alloc_page returns NULL with
-EAGAIN), we jump to free_err where the condition:
if (skb && !skb_shinfo(skb)->nr_frags)
kfree_skb(skb);
evaluates to true because nr_frags is still 0 (the first descriptor
used the linear area, not frags). This frees the skb while xs->skb
still points to it, creating a dangling pointer. On the next transmit
attempt or socket close, xs->skb is dereferenced, causing a
use-after-free or double-free.
Fix by using a !xs->skb check to handle first frag situation, ensuring
we only free skbs that were freshly allocated in this call
(xs->skb is NULL) and never free an in-progress multi-buffer skb that
the caller still references.
Closes: https://lore.kernel.org/all/20260415082654.21026-4-kerneljasonxing@gmail.com/
Fixes: 6b9c129c2f ("xsk: remove @first_frag from xsk_build_skb()")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20260502200722.53960-5-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When a first descriptor (xs->skb == NULL) triggers -EOVERFLOW in
xsk_build_skb_zerocopy() (e.g., MAX_SKB_FRAGS exceeded), the
free_err -EOVERFLOW handler unconditionally dereferences xs->skb
via xsk_inc_num_desc(xs->skb) and xsk_drop_skb(xs->skb), causing
a NULL pointer dereference.
Fix this by guarding the existing xsk_inc_num_desc()/xsk_drop_skb()
calls with an xs->skb check (for the continuation case), and add
an else branch for the first-descriptor case that manually cancels
the one reserved CQ slot and increments invalid_descs by one to
account for the single invalid descriptor.
Fixes: cf24f5a5fe ("xsk: add support for AF_XDP multi-buffer on Tx path")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20260502200722.53960-4-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix it by explicitly adding kfree_skb() before returning back to its
caller.
How to reproduce it in virtio_net:
1. the current skb is the first one (which means xs->skb is NULL) and
hit the limit MAX_SKB_FRAGS.
2. xsk_build_skb_zerocopy() returns -EOVERFLOW.
3. the caller xsk_build_skb() clears skb by using 'skb = NULL;'. This
is why bug can be triggered.
4. there is no chance to free this skb anymore.
Note that if in this case the xs->skb is not NULL, xsk_build_skb() will
call xsk_drop_skb(xs->skb) to do the right thing.
Fixes: cf24f5a5fe ("xsk: add support for AF_XDP multi-buffer on Tx path")
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20260502200722.53960-3-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
skb_checksum_help() is a common helper that writes the folded
16-bit checksum back via skb->data + csum_start + csum_offset,
i.e. it relies on the skb's linear head and fails (with WARN_ONCE
and -EINVAL) when skb_headlen() is 0.
AF_XDP generic xmit takes two very different paths depending on the
netdev. Drivers that advertise IFF_TX_SKB_NO_LINEAR (e.g. virtio_net)
skip the "copy payload into a linear head" step on purpose as a
performance optimisation: xsk_build_skb_zerocopy() only attaches UMEM
pages as frags and never calls skb_put(), so skb_headlen() stays 0
for the whole skb. For these skbs there is simply no linear area for
skb_checksum_help() to write the csum into - the sw-csum fallback is
structurally inapplicable.
The patch tries to catch this and reject the combination with error at
setup time. Rejecting at bind() converts this silent per-packet failure
into a synchronous, actionable -EOPNOTSUPP at setup time. HW csum and
launch_time metadata on IFF_TX_SKB_NO_LINEAR drivers are unaffected
because they do not call skb_checksum_help().
Without the patch, every descriptor carrying 'XDP_TX_METADATA |
XDP_TXMD_FLAGS_CHECKSUM' produces:
1) a WARN_ONCE "offset (N) >= skb_headlen() (0)" from skb_checksum_help(),
2) sendmsg() returning -EINVAL without consuming the descriptor
(invalid_descs is not incremented),
3) a wedged TX ring: __xsk_generic_xmit() does not advance the
consumer on non-EOVERFLOW errors, so the next sendmsg() re-reads
the same descriptor and re-hits the same WARN until the socket
is closed.
Closes: https://lore.kernel.org/all/20260419045822.843BFC2BCAF@smtp.kernel.org/#t
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Fixes: 30c3055f9c ("xsk: wrap generic metadata handling onto separate function")
Link: https://patch.msgid.link/20260502200722.53960-2-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
