Linux: >> Linux Kernel >> 6.18.11 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for handle opening
Even privileged services should not necessarily be able to see other
privileged service's namespaces so they can't leak information to each
other. Use may_see_all_namespaces() helper that centralizes this policy
until the nstree adapts.
CVSS Score
8.8
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Fix starvation of scx_enable() under fair-class saturation
During scx_enable(), the READY -> ENABLED task switching loop changes the
calling thread's sched_class from fair to ext. Since fair has higher
priority than ext, saturating fair-class workloads can indefinitely starve
the enable thread, hanging the system. This was introduced when the enable
path switched from preempt_disable() to scx_bypass() which doesn't protect
against fair-class starvation. Note that the original preempt_disable()
protection wasn't complete either - in partial switch modes, the calling
thread could still be starved after preempt_enable() as it may have been
switched to ext class.
Fix it by offloading the enable body to a dedicated system-wide RT
(SCHED_FIFO) kthread which cannot be starved by either fair or ext class
tasks. scx_enable() lazily creates the kthread on first use and passes the
ops pointer through a struct scx_enable_cmd containing the kthread_work,
then synchronously waits for completion.
The workfn runs on a different kthread from sch->helper (which runs
disable_work), so it can safely flush disable_work on the error path
without deadlock.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix chunk map leak in btrfs_map_block() after btrfs_chunk_map_num_copies()
Fix a chunk map leak in btrfs_map_block(): if we return early with -EINVAL,
we're not freeing the chunk map that we've just looked up.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
nfsd: Fix cred ref leak in nfsd_nl_listener_set_doit().
nfsd_nl_listener_set_doit() uses get_current_cred() without
put_cred().
As we can see from other callers, svc_xprt_create_from_sa()
does not require the extra refcount.
nfsd_nl_listener_set_doit() is always in the process context,
sendmsg(), and current->cred does not go away.
Let's use current_cred() in nfsd_nl_listener_set_doit().
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
drm/xe/sync: Cleanup partially initialized sync on parse failure
xe_sync_entry_parse() can allocate references (syncobj, fence, chain fence,
or user fence) before hitting a later failure path. Several of those paths
returned directly, leaving partially initialized state and leaking refs.
Route these error paths through a common free_sync label and call
xe_sync_entry_cleanup(sync) before returning the error.
(cherry picked from commit f939bdd9207a5d1fc55cced5459858480686ce22)
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()
opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is being
accessed after rcu_read_unlock() has been called. This creates a
race condition where the memory could be freed by a concurrent
writer between the unlock and the subsequent pointer dereferences
(opinfo->is_lease, etc.), leading to a use-after-free.
CVSS Score
9.8
EPSS Score
0.004
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/q54sj108a2) fix stack overflow in debugfs read
The q54sj108a2_debugfs_read function suffers from a stack buffer overflow
due to incorrect arguments passed to bin2hex(). The function currently
passes 'data' as the destination and 'data_char' as the source.
Because bin2hex() converts each input byte into two hex characters, a
32-byte block read results in 64 bytes of output. Since 'data' is only
34 bytes (I2C_SMBUS_BLOCK_MAX + 2), this writes 30 bytes past the end
of the buffer onto the stack.
Additionally, the arguments were swapped: it was reading from the
zero-initialized 'data_char' and writing to 'data', resulting in
all-zero output regardless of the actual I2C read.
Fix this by:
1. Expanding 'data_char' to 66 bytes to safely hold the hex output.
2. Correcting the bin2hex() argument order and using the actual read count.
3. Using a pointer to select the correct output buffer for the final
simple_read_from_buffer call.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
nouveau/dpcd: return EBUSY for aux xfer if the device is asleep
If we have runtime suspended, and userspace wants to use /dev/drm_dp_*
then just tell it the device is busy instead of crashing in the GSP
code.
WARNING: CPU: 2 PID: 565741 at drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/rpc.c:164 r535_gsp_msgq_wait+0x9a/0xb0 [nouveau]
CPU: 2 UID: 0 PID: 565741 Comm: fwupd Not tainted 6.18.10-200.fc43.x86_64 #1 PREEMPT(lazy)
Hardware name: LENOVO 20QTS0PQ00/20QTS0PQ00, BIOS N2OET65W (1.52 ) 08/05/2024
RIP: 0010:r535_gsp_msgq_wait+0x9a/0xb0 [nouveau]
This is a simple fix to get backported. We should probably engineer a
proper power domain solution to wake up devices and keep them awake
while fw updates are happening.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: Avoid double-rtnl_lock ELP metric worker
batadv_v_elp_get_throughput() might be called when the RTNL lock is already
held. This could be problematic when the work queue item is cancelled via
cancel_delayed_work_sync() in batadv_v_elp_iface_disable(). In this case,
an rtnl_lock() would cause a deadlock.
To avoid this, rtnl_trylock() was used in this function to skip the
retrieval of the ethtool information in case the RTNL lock was already
held.
But for cfg80211 interfaces, batadv_get_real_netdev() was called - which
also uses rtnl_lock(). The approach for __ethtool_get_link_ksettings() must
also be used instead and the lockless version __batadv_get_real_netdev()
has to be called.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-08
In the Linux kernel, the following vulnerability has been resolved:
net/tcp-md5: Fix MAC comparison to be constant-time
To prevent timing attacks, MACs need to be compared in constant
time. Use the appropriate helper function for this.
CVSS Score
9.4
EPSS Score
0.004
Published
2026-05-08