Linux: >> Linux Kernel >> 5.15.10 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: Fix static_branch_dec() underflow for aql_disable.
syzbot reported static_branch_dec() underflow in aql_enable_write(). [0]
The problem is that aql_enable_write() does not serialise concurrent
write()s to the debugfs.
aql_enable_write() checks static_key_false(&aql_disable.key) and
later calls static_branch_inc() or static_branch_dec(), but the
state may change between the two calls.
aql_disable does not need to track inc/dec.
Let's use static_branch_enable() and static_branch_disable().
[0]:
val == 0
WARNING: kernel/jump_label.c:311 at __static_key_slow_dec_cpuslocked.part.0+0x107/0x120 kernel/jump_label.c:311, CPU#0: syz.1.3155/20288
Modules linked in:
CPU: 0 UID: 0 PID: 20288 Comm: syz.1.3155 Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:__static_key_slow_dec_cpuslocked.part.0+0x107/0x120 kernel/jump_label.c:311
Code: f2 c9 ff 5b 5d c3 cc cc cc cc e8 54 f2 c9 ff 48 89 df e8 ac f9 ff ff eb ad e8 45 f2 c9 ff 90 0f 0b 90 eb a2 e8 3a f2 c9 ff 90 <0f> 0b 90 eb 97 48 89 df e8 5c 4b 33 00 e9 36 ff ff ff 0f 1f 80 00
RSP: 0018:ffffc9000b9f7c10 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffffff9b3e5d40 RCX: ffffffff823c57b4
RDX: ffff8880285a0000 RSI: ffffffff823c5846 RDI: ffff8880285a0000
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000000a
R13: 1ffff9200173ef88 R14: 0000000000000001 R15: ffffc9000b9f7e98
FS: 00007f530dd726c0(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001140 CR3: 000000007cc4a000 CR4: 00000000003526f0
Call Trace:
<TASK>
__static_key_slow_dec_cpuslocked kernel/jump_label.c:297 [inline]
__static_key_slow_dec kernel/jump_label.c:321 [inline]
static_key_slow_dec+0x7c/0xc0 kernel/jump_label.c:336
aql_enable_write+0x2b2/0x310 net/mac80211/debugfs.c:343
short_proxy_write+0x133/0x1a0 fs/debugfs/file.c:383
vfs_write+0x2aa/0x1070 fs/read_write.c:684
ksys_pwrite64 fs/read_write.c:793 [inline]
__do_sys_pwrite64 fs/read_write.c:801 [inline]
__se_sys_pwrite64 fs/read_write.c:798 [inline]
__x64_sys_pwrite64+0x1eb/0x250 fs/read_write.c:798
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f530cf9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f530dd72028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f530d215fa0 RCX: 00007f530cf9aeb9
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000010
RBP: 00007f530d008c1f R08: 0000000000000000 R09: 0000000000000000
R10: 4200000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f530d216038 R14: 00007f530d215fa0 R15: 00007ffde89fb978
</TASK>
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
futex: Clear stale exiting pointer in futex_lock_pi() retry path
Fuzzying/stressing futexes triggered:
WARNING: kernel/futex/core.c:825 at wait_for_owner_exiting+0x7a/0x80, CPU#11: futex_lock_pi_s/524
When futex_lock_pi_atomic() sees the owner is exiting, it returns -EBUSY
and stores a refcounted task pointer in 'exiting'.
After wait_for_owner_exiting() consumes that reference, the local pointer
is never reset to nil. Upon a retry, if futex_lock_pi_atomic() returns a
different error, the bogus pointer is passed to wait_for_owner_exiting().
CPU0 CPU1 CPU2
futex_lock_pi(uaddr)
// acquires the PI futex
exit()
futex_cleanup_begin()
futex_state = EXITING;
futex_lock_pi(uaddr)
futex_lock_pi_atomic()
attach_to_pi_owner()
// observes EXITING
*exiting = owner; // takes ref
return -EBUSY
wait_for_owner_exiting(-EBUSY, owner)
put_task_struct(); // drops ref
// exiting still points to owner
goto retry;
futex_lock_pi_atomic()
lock_pi_update_atomic()
cmpxchg(uaddr)
*uaddr ^= WAITERS // whatever
// value changed
return -EAGAIN;
wait_for_owner_exiting(-EAGAIN, exiting) // stale
WARN_ON_ONCE(exiting)
Fix this by resetting upon retry, essentially aligning it with requeue_pi.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
NFC: nxp-nci: allow GPIOs to sleep
Allow the firmware and enable GPIOs to sleep.
This fixes a `WARN_ON' and allows the driver to operate GPIOs which are
connected to I2C GPIO expanders.
-- >8 --
kernel: WARNING: CPU: 3 PID: 2636 at drivers/gpio/gpiolib.c:3880 gpiod_set_value+0x88/0x98
-- >8 --
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
net: bonding: fix NULL deref in bond_debug_rlb_hash_show
rlb_clear_slave intentionally keeps RLB hash-table entries on
the rx_hashtbl_used_head list with slave set to NULL when no
replacement slave is available. However, bond_debug_rlb_hash_show
visites client_info->slave without checking if it's NULL.
Other used-list iterators in bond_alb.c already handle this NULL-slave
state safely:
- rlb_update_client returns early on !client_info->slave
- rlb_req_update_slave_clients, rlb_clear_slave, and rlb_rebalance
compare slave values before visiting
- lb_req_update_subnet_clients continues if slave is NULL
The following NULL deref crash can be trigger in
bond_debug_rlb_hash_show:
[ 1.289791] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 1.292058] RIP: 0010:bond_debug_rlb_hash_show (drivers/net/bonding/bond_debugfs.c:41)
[ 1.293101] RSP: 0018:ffffc900004a7d00 EFLAGS: 00010286
[ 1.293333] RAX: 0000000000000000 RBX: ffff888102b48200 RCX: ffff888102b48204
[ 1.293631] RDX: ffff888102b48200 RSI: ffffffff839daad5 RDI: ffff888102815078
[ 1.293924] RBP: ffff888102815078 R08: ffff888102b4820e R09: 0000000000000000
[ 1.294267] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888100f929c0
[ 1.294564] R13: ffff888100f92a00 R14: 0000000000000001 R15: ffffc900004a7ed8
[ 1.294864] FS: 0000000001395380(0000) GS:ffff888196e75000(0000) knlGS:0000000000000000
[ 1.295239] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1.295480] CR2: 0000000000000000 CR3: 0000000102adc004 CR4: 0000000000772ef0
[ 1.295897] Call Trace:
[ 1.296134] seq_read_iter (fs/seq_file.c:231)
[ 1.296341] seq_read (fs/seq_file.c:164)
[ 1.296493] full_proxy_read (fs/debugfs/file.c:378 (discriminator 1))
[ 1.296658] vfs_read (fs/read_write.c:572)
[ 1.296981] ksys_read (fs/read_write.c:717)
[ 1.297132] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[ 1.297325] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Add a NULL check and print "(none)" for entries with no assigned slave.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
wifi: cfg80211: cancel pmsr_free_wk in cfg80211_pmsr_wdev_down
When the nl80211 socket that originated a PMSR request is
closed, cfg80211_release_pmsr() sets the request's nl_portid
to zero and schedules pmsr_free_wk to process the abort
asynchronously. If the interface is concurrently torn down
before that work runs, cfg80211_pmsr_wdev_down() calls
cfg80211_pmsr_process_abort() directly. However, the already-
scheduled pmsr_free_wk work item remains pending and may run
after the interface has been removed from the driver. This
could cause the driver's abort_pmsr callback to operate on a
torn-down interface, leading to undefined behavior and
potential crashes.
Cancel pmsr_free_wk synchronously in cfg80211_pmsr_wdev_down()
before calling cfg80211_pmsr_process_abort(). This ensures any
pending or in-progress work is drained before interface teardown
proceeds, preventing the work from invoking the driver abort
callback after the interface is gone.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
smb: server: let send_done handle a completion without IB_SEND_SIGNALED
With smbdirect_send_batch processing we likely have requests without
IB_SEND_SIGNALED, which will be destroyed in the final request
that has IB_SEND_SIGNALED set.
If the connection is broken all requests are signaled
even without explicit IB_SEND_SIGNALED.
CVSS Score
9.8
EPSS Score
0.004
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
smb: server: make use of smbdirect_socket.send_io.bcredits
It turns out that our code will corrupt the stream of
reassabled data transfer messages when we trigger an
immendiate (empty) send.
In order to fix this we'll have a single 'batch' credit per
connection. And code getting that credit is free to use
as much messages until remaining_length reaches 0, then
the batch credit it given back and the next logical send can
happen.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: Check set_default_submission() before deferencing
When the i915 driver firmware binaries are not present, the
set_default_submission pointer is not set. This pointer is
dereferenced during suspend anyways.
Add a check to make sure it is set before dereferencing.
[ 23.289926] PM: suspend entry (deep)
[ 23.293558] Filesystems sync: 0.000 seconds
[ 23.298010] Freezing user space processes
[ 23.302771] Freezing user space processes completed (elapsed 0.000 seconds)
[ 23.309766] OOM killer disabled.
[ 23.313027] Freezing remaining freezable tasks
[ 23.318540] Freezing remaining freezable tasks completed (elapsed 0.001 seconds)
[ 23.342038] serial 00:05: disabled
[ 23.345719] serial 00:02: disabled
[ 23.349342] serial 00:01: disabled
[ 23.353782] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[ 23.358993] sd 1:0:0:0: [sdb] Synchronizing SCSI cache
[ 23.361635] ata1.00: Entering standby power mode
[ 23.368863] ata2.00: Entering standby power mode
[ 23.445187] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 23.452194] #PF: supervisor instruction fetch in kernel mode
[ 23.457896] #PF: error_code(0x0010) - not-present page
[ 23.463065] PGD 0 P4D 0
[ 23.465640] Oops: Oops: 0010 [#1] SMP NOPTI
[ 23.469869] CPU: 8 UID: 0 PID: 211 Comm: kworker/u48:18 Tainted: G S W 6.19.0-rc4-00020-gf0b9d8eb98df #10 PREEMPT(voluntary)
[ 23.482512] Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN
[ 23.496511] Workqueue: async async_run_entry_fn
[ 23.501087] RIP: 0010:0x0
[ 23.503755] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[ 23.510324] RSP: 0018:ffffb4a60065fca8 EFLAGS: 00010246
[ 23.515592] RAX: 0000000000000000 RBX: ffff9f428290e000 RCX: 000000000000000f
[ 23.522765] RDX: 0000000000000000 RSI: 0000000000000282 RDI: ffff9f428290e000
[ 23.529937] RBP: ffff9f4282907070 R08: ffff9f4281130428 R09: 00000000ffffffff
[ 23.537111] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9f42829070f8
[ 23.544284] R13: ffff9f4282906028 R14: ffff9f4282900000 R15: ffff9f4282906b68
[ 23.551457] FS: 0000000000000000(0000) GS:ffff9f466b2cf000(0000) knlGS:0000000000000000
[ 23.559588] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 23.565365] CR2: ffffffffffffffd6 CR3: 000000031c230001 CR4: 0000000000f70ef0
[ 23.572539] PKRU: 55555554
[ 23.575281] Call Trace:
[ 23.577770] <TASK>
[ 23.579905] intel_engines_reset_default_submission+0x42/0x60
[ 23.585695] __intel_gt_unset_wedged+0x191/0x200
[ 23.590360] intel_gt_unset_wedged+0x20/0x40
[ 23.594675] gt_sanitize+0x15e/0x170
[ 23.598290] i915_gem_suspend_late+0x6b/0x180
[ 23.602692] i915_drm_suspend_late+0x35/0xf0
[ 23.607008] ? __pfx_pci_pm_suspend_late+0x10/0x10
[ 23.611843] dpm_run_callback+0x78/0x1c0
[ 23.615817] device_suspend_late+0xde/0x2e0
[ 23.620037] async_suspend_late+0x18/0x30
[ 23.624082] async_run_entry_fn+0x25/0xa0
[ 23.628129] process_one_work+0x15b/0x380
[ 23.632182] worker_thread+0x2a5/0x3c0
[ 23.635973] ? __pfx_worker_thread+0x10/0x10
[ 23.640279] kthread+0xf6/0x1f0
[ 23.643464] ? __pfx_kthread+0x10/0x10
[ 23.647263] ? __pfx_kthread+0x10/0x10
[ 23.651045] ret_from_fork+0x131/0x190
[ 23.654837] ? __pfx_kthread+0x10/0x10
[ 23.658634] ret_from_fork_asm+0x1a/0x30
[ 23.662597] </TASK>
[ 23.664826] Modules linked in:
[ 23.667914] CR2: 0000000000000000
[ 23.671271] ------------[ cut here ]------------
(cherry picked from commit daa199abc3d3d1740c9e3a2c3e9216ae5b447cad)
CVSS Score
5.5
EPSS Score
0.001
Published
2026-04-24
In the Linux kernel, the following vulnerability has been resolved:
ipv4: nexthop: allocate skb dynamically in rtm_get_nexthop()
When querying a nexthop object via RTM_GETNEXTHOP, the kernel currently
allocates a fixed-size skb using NLMSG_GOODSIZE. While sufficient for
single nexthops and small Equal-Cost Multi-Path groups, this fixed
allocation fails for large nexthop groups like 512 nexthops.
This results in the following warning splat:
WARNING: net/ipv4/nexthop.c:3395 at rtm_get_nexthop+0x176/0x1c0, CPU#20: rep/4608
[...]
RIP: 0010:rtm_get_nexthop (net/ipv4/nexthop.c:3395)
[...]
Call Trace:
<TASK>
rtnetlink_rcv_msg (net/core/rtnetlink.c:6989)
netlink_rcv_skb (net/netlink/af_netlink.c:2550)
netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
netlink_sendmsg (net/netlink/af_netlink.c:1894)
____sys_sendmsg (net/socket.c:721 net/socket.c:736 net/socket.c:2585)
___sys_sendmsg (net/socket.c:2641)
__sys_sendmsg (net/socket.c:2671)
do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
</TASK>
Fix this by allocating the size dynamically using nh_nlmsg_size() and
using nlmsg_new(), this is consistent with nexthop_notify() behavior. In
addition, adjust nh_nlmsg_size_grp() so it calculates the size needed
based on flags passed. While at it, also add the size of NHA_FDB for
nexthop group size calculation as it was missing too.
This cannot be reproduced via iproute2 as the group size is currently
limited and the command fails as follows:
addattr_l ERROR: message exceeded bound of 1048
CVSS Score
5.5
EPSS Score
0.002
Published
2026-04-23
In the Linux kernel, the following vulnerability has been resolved:
can: raw: fix ro->uniq use-after-free in raw_rcv()
raw_release() unregisters raw CAN receive filters via can_rx_unregister(),
but receiver deletion is deferred with call_rcu(). This leaves a window
where raw_rcv() may still be running in an RCU read-side critical section
after raw_release() frees ro->uniq, leading to a use-after-free of the
percpu uniq storage.
Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific
socket destructor. can_rx_unregister() takes an extra reference to the
socket and only drops it from the RCU callback, so freeing uniq from
sk_destruct ensures the percpu area is not released until the relevant
callbacks have drained.
[mkl: applied manually]
CVSS Score
7.8
EPSS Score
0.001
Published
2026-04-23