Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
can: ucan: fix devres lifetime
USB drivers bind to USB interfaces and any device managed resources
should have their lifetime tied to the interface rather than parent USB
device. This avoids issues like memory leaks when drivers are unbound
without their devices being physically disconnected (e.g. on probe
deferral or configuration changes).
Fix the control message buffer lifetime so that it is released on driver
unbind.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
md/md-llbitmap: raise barrier before state machine transition
Move the barrier raise operation before calling llbitmap_state_machine()
in both llbitmap_start_write() and llbitmap_start_discard(). This
ensures the barrier is in place before any state transitions occur,
preventing potential race conditions where the state machine could
complete before the barrier is properly raised.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
tpm2-sessions: Fix missing tpm_buf_destroy() in tpm2_read_public()
tpm2_read_public() calls tpm_buf_init() but fails to call
tpm_buf_destroy() on two exit paths, leaking a page allocation:
1. When name_size() returns an error (unrecognized hash algorithm),
the function returns directly without destroying the buffer.
2. On the success path, the buffer is never destroyed before
returning.
All other error paths in the function correctly call
tpm_buf_destroy() before returning.
Fix both by adding the missing tpm_buf_destroy() calls.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
Input: edt-ft5x06 - fix use-after-free in debugfs teardown
The commit 68743c500c6e ("Input: edt-ft5x06 - use per-client debugfs
directory") removed the manual debugfs teardown, relying on the I2C core
to handle it. However, this creates a window where debugfs files are
still accessible after edt_ft5x06_ts_teardown_debugfs() frees
tsdata->raw_buffer.
To prevent a use-after-free, protect the freeing of raw_buffer with the
device mutex and set raw_buffer to NULL. The debugfs read function
already checks if raw_buffer is NULL under the same mutex, so this
safely avoids the use-after-free.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
net: caif: clear client service pointer on teardown
`caif_connect()` can tear down an existing client after remote shutdown by
calling `caif_disconnect_client()` followed by `caif_free_client()`.
`caif_free_client()` releases the service layer referenced by
`adap_layer->dn`, but leaves that pointer stale.
When the socket is later destroyed, `caif_sock_destructor()` calls
`caif_free_client()` again and dereferences the freed service pointer.
Clear the client/service links before releasing the service object so
repeated teardown becomes harmless.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
net: ipv6: fix NOREF dst use in seg6 and rpl lwtunnels
seg6_input_core() and rpl_input() call ip6_route_input() which sets a
NOREF dst on the skb, then pass it to dst_cache_set_ip6() invoking
dst_hold() unconditionally.
On PREEMPT_RT, ksoftirqd is preemptible and a higher-priority task can
release the underlying pcpu_rt between the lookup and the caching
through a concurrent FIB lookup on a shared nexthop.
Simplified race sequence:
ksoftirqd/X higher-prio task (same CPU X)
----------- --------------------------------
seg6_input_core(,skb)/rpl_input(skb)
dst_cache_get()
-> miss
ip6_route_input(skb)
-> ip6_pol_route(,skb,flags)
[RT6_LOOKUP_F_DST_NOREF in flags]
-> FIB lookup resolves fib6_nh
[nhid=N route]
-> rt6_make_pcpu_route()
[creates pcpu_rt, refcount=1]
pcpu_rt->sernum = fib6_sernum
[fib6_sernum=W]
-> cmpxchg(fib6_nh.rt6i_pcpu,
NULL, pcpu_rt)
[slot was empty, store succeeds]
-> skb_dst_set_noref(skb, dst)
[dst is pcpu_rt, refcount still 1]
rt_genid_bump_ipv6()
-> bumps fib6_sernum
[fib6_sernum from W to Z]
ip6_route_output()
-> ip6_pol_route()
-> FIB lookup resolves fib6_nh
[nhid=N]
-> rt6_get_pcpu_route()
pcpu_rt->sernum != fib6_sernum
[W <> Z, stale]
-> prev = xchg(rt6i_pcpu, NULL)
-> dst_release(prev)
[prev is pcpu_rt,
refcount 1->0, dead]
dst = skb_dst(skb)
[dst is the dead pcpu_rt]
dst_cache_set_ip6(dst)
-> dst_hold() on dead dst
-> WARN / use-after-free
For the race to occur, ksoftirqd must be preemptible (PREEMPT_RT without
PREEMPT_RT_NEEDS_BH_LOCK) and a concurrent task must be able to release
the pcpu_rt. Shared nexthop objects provide such a path, as two routes
pointing to the same nhid share the same fib6_nh and its rt6i_pcpu
entry.
Fix seg6_input_core() and rpl_input() by calling skb_dst_force() after
ip6_route_input() to force the NOREF dst into a refcounted one before
caching.
The output path is not affected as ip6_route_output() already returns a
refcounted dst.
CVSS Score
8.1
EPSS Score
0.004
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
fs: afs: revert mmap_prepare() change
Partially reverts commit 9d5403b1036c ("fs: convert most other
generic_file_*mmap() users to .mmap_prepare()").
This is because the .mmap invocation establishes a refcount, but
.mmap_prepare is called at a point where a merge or an allocation failure
might happen after the call, which would leak the refcount increment.
Functionality is being added to permit the use of .mmap_prepare in this
case, but in the interim, we need to fix this.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: use a stable FDB dst snapshot in RCU readers
Local FDB entries can be rewritten in place by `fdb_delete_local()`, which
updates `f->dst` to another port or to `NULL` while keeping the entry
alive. Several bridge RCU readers inspect `f->dst`, including
`br_fdb_fillbuf()` through the `brforward_read()` sysfs path.
These readers currently load `f->dst` multiple times and can therefore
observe inconsistent values across the check and later dereference.
In `br_fdb_fillbuf()`, this means a concurrent local-FDB update can change
`f->dst` after the NULL check and before the `port_no` dereference,
leading to a NULL-ptr-deref.
Fix this by taking a single `READ_ONCE()` snapshot of `f->dst` in each
affected RCU reader and using that snapshot for the rest of the access
sequence. Also publish the in-place `f->dst` updates in `fdb_delete_local()`
with `WRITE_ONCE()` so the readers and writer use matching access patterns.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/stat: fix memory leak on damon_start() failure in damon_stat_start()
Destroy the DAMON context and reset the global pointer when damon_start()
fails. Otherwise, the context allocated by damon_stat_build_ctx() is
leaked, and the stale damon_stat_context pointer will be overwritten on
the next enable attempt, making the old allocation permanently
unreachable.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27
In the Linux kernel, the following vulnerability has been resolved:
ALSA: control: Validate buf_len before strnlen() in snd_ctl_elem_init_enum_names()
snd_ctl_elem_init_enum_names() advances pointer p through the names
buffer while decrementing buf_len. If buf_len reaches zero but items
remain, the next iteration calls strnlen(p, 0).
While strnlen(p, 0) returns 0 and would hit the existing name_len == 0
error path, CONFIG_FORTIFY_SOURCE's fortified strnlen() first checks
maxlen against __builtin_dynamic_object_size(). When Clang loses track
of p's object size inside the loop, this triggers a BRK exception panic
before the return value is examined.
Add a buf_len == 0 guard at the loop entry to prevent calling fortified
strnlen() on an exhausted buffer.
Found by kernel fuzz testing through Xiaomi Smartphone.
CVSS Score
5.5
EPSS Score
0.002
Published
2026-05-27