Linux: >> Linux Kernel >> 6.18.35 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
net/tcp-ao: fix use-after-free of key in del_async path
In tcp_ao_delete_key(), the del_async path skips the current_key
and rnext_key validity checks present in the synchronous path,
assuming these pointers are always NULL on LISTEN sockets. However,
if a key was added with set_current=1/set_rnext=1 while the socket
was in CLOSE state, current_key and rnext_key will be non-NULL
after listen() transitions the socket to LISTEN.
When such a key is deleted with del_async=1, hlist_del_rcu() and
call_rcu() free the key without clearing the dangling pointers.
After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences
current_key->sndid and rnext_key->rcvid from freed slab memory.
Clear current_key and rnext_key in the del_async path when they
reference the key being deleted.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
virtiofs: fix UAF on submount umount
iput() called from fuse_release_end() can Oops if the super block has
already been destroyed. Normally this is prevented by waiting for
num_waiting to go down to zero before commencing with super block shutdown.
This only works, however, for the last submount instance, as the wait
counter is per connection, not per superblock.
Revert to using synchronous release requests for the auto_submounts case,
which is virtiofs only at this time.
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
media: vidtv: fix NULL pointer dereference in vidtv_mux_push_si
syzbot reported a general protection fault in
vidtv_psi_ts_psi_write_into [1].
vidtv_mux_get_pid_ctx() can return NULL, but vidtv_mux_push_si() does
not check for this before dereferencing the returned pointer to access
the continuity counter. This leads to a general protection fault when
accessing a near-NULL address.
The root cause is that vidtv_mux_pid_ctx_init() does not check the
return value of vidtv_mux_create_pid_ctx_once() for PMT section PIDs.
If the allocation fails, the PID context is never created, but init
returns success. The subsequent vidtv_mux_push_si() call then gets
NULL from vidtv_mux_get_pid_ctx() and crashes.
Fix both the root cause (add error check in vidtv_mux_pid_ctx_init
for PMT PIDs) and add defensive NULL checks in vidtv_mux_push_si for
all vidtv_mux_get_pid_ctx() calls.
[1]
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Workqueue: events vidtv_mux_tick
RIP: 0010:vidtv_psi_ts_psi_write_into+0x54a/0xbc0 drivers/media/test-drivers/vidtv/vidtv_psi.c:197
Call Trace:
<TASK>
vidtv_psi_table_header_write_into drivers/media/test-drivers/vidtv/vidtv_psi.c:799 [inline]
vidtv_psi_pmt_write_into+0x3b2/0xa70 drivers/media/test-drivers/vidtv/vidtv_psi.c:1231
vidtv_mux_push_si+0x932/0xe80 drivers/media/test-drivers/vidtv/vidtv_mux.c:196
vidtv_mux_tick+0xe9b/0x1480 drivers/media/test-drivers/vidtv/vidtv_mux.c:408
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-19
In the Linux kernel, the following vulnerability has been resolved:
ipv4: account for fraggap on the paged allocation path
In __ip_append_data(), when the paged-allocation branch is taken,
alloclen and pagedlen are computed as
alloclen = fragheaderlen + transhdrlen;
pagedlen = datalen - transhdrlen;
datalen already includes fraggap, but the fraggap bytes carried over
from the previous skb are copied into the new skb's linear area at
offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The
linear area is therefore undersized by fraggap bytes while pagedlen is
overstated by the same amount.
The non-paged branch sets alloclen to fraglen, which already accounts
for fraggap because datalen does. Bring the paged branch in line by
adding fraggap to alloclen and subtracting it from pagedlen.
After this adjustment, copy no longer collapses to -fraggap on the
paged path, so remove the stale comment describing that old arithmetic.
CVSS Score
7.8
EPSS Score
0.002
Published
2026-07-16
In the Linux kernel, the following vulnerability has been resolved:
xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags()
iptfs_consume_frags() transfers paged fragments from one socket buffer
to another but fails to propagate the SKBFL_SHARED_FRAG flag. This is
the same class of bug that was fixed in skb_try_coalesce() for
CVE-2026-46300: when fragments backed by read-only page-cache pages are
merged, the marker indicating their shared nature must be preserved so
that ESP can decide correctly whether in-place encryption is safe.
Apply the same two-line fix used in skb_try_coalesce() to
iptfs_consume_frags().
CVSS Score
9.8
EPSS Score
0.003
Published
2026-07-10
In the Linux kernel, the following vulnerability has been resolved:
af_unix: Set gc_in_progress to true in unix_gc().
Igor Ushakov reported that unix_gc() could run with gc_in_progress
being false if the work is scheduled while running:
Thread 1 Thread 2 Thread 3
-------- -------- --------
unix_schedule_gc() unix_schedule_gc()
`- if (!gc_in_progress) `- if (!gc_in_progress)
|- gc_in_progress = true |
`- queue_work() |
unix_gc() <----------------/ |
| |- gc_in_progress = true
... `- queue_work()
| |
`- gc_in_progress = false |
|
unix_gc() <---------------------------------------------'
|
... /* gc_in_progress == false */
|
`- gc_in_progress = false
unix_peek_fpl() relies on gc_in_progress not to confuse GC
by MSG_PEEK.
Let's set gc_in_progress to true in unix_gc().
CVSS Score
7.1
EPSS Score
0.001
Published
2026-07-04
CVE-2026-53362
In the Linux kernel, the following vulnerability has been resolved:
ipv6: account for fraggap on the paged allocation path
In __ip6_append_data(), when the paged-allocation branch is taken
(MSG_MORE / NETIF_F_SG / large fraglen), alloclen and pagedlen are
computed as
alloclen = fragheaderlen + transhdrlen;
pagedlen = datalen - transhdrlen;
datalen already includes fraggap (datalen = length + fraggap). When
fraggap is non-zero, this is not the first skb and transhdrlen is zero.
The fraggap bytes carried over from the previous skb are copied just past
the fragment headers in the new skb's linear area. The linear area is
therefore undersized by fraggap bytes while pagedlen is overstated by the
same amount, and the copy writes past skb->end into the trailing
skb_shared_info.
An unprivileged user can trigger this via a UDPv6 socket using
MSG_MORE together with MSG_SPLICE_PAGES.
The bad accounting was introduced by commit 773ba4fe9104 ("ipv6:
avoid partial copy for zc"). Before commit ce650a166335 ("udp6: Fix
__ip6_append_data()'s handling of MSG_SPLICE_PAGES"), the negative
copy value caused -EINVAL to be returned. That later commit allowed
MSG_SPLICE_PAGES to proceed in this case, making the corruption
triggerable.
The non-paged branch sets alloclen to fraglen, which already accounts
for fraggap because datalen does. Bring the paged branch in line by
adding fraggap to alloclen and subtracting it from pagedlen.
After this adjustment, copy no longer collapses to -fraggap on the
paged path, so remove the stale comment describing that old arithmetic.
Since a negative copy is no longer expected for a valid MSG_SPLICE_PAGES
case, remove the MSG_SPLICE_PAGES exception from the negative copy check.
Known exploited
CVSS Score
7.8
EPSS Score
0.003
Published
2026-07-04
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Fix shadow paging use-after-free due to unexpected role
Commit 0cb2af2ea66ad ("KVM: x86: Fix shadow paging use-after-free due
to unexpected GFN") fixed a shadow paging mismatch between stored and
computed GFNs; the bug could be triggered by changing a PDE mapping from
outside the guest, and then deleting a memslot. The rmap_remove()
call would miss entries created after the PDE change because the GFN
of the leaf SPTE does not match the GFN of the struct kvm_mmu_page.
A similar hole however remains if the modified PDE points to a non-leaf
page. In this case the gfn can be made to match, but the role does not
match: the original large 2MB page creates a kvm_mmu_page with direct=1,
while the new 4KB needs a kvm_mmu_page with direct=0. However,
kvm_mmu_get_child_sp() does not compare the role, and therefore reuses
the page.
The next step is installing a leaf (4KB) SPTE on the new path which
records an rmap entry under the gfn resolved by the walk. But when
that child is zapped its parent kvm_mmu_page has direct=1 and
kvm_mmu_page_get_gfn() computes the gfn for the 4KB page as
sp->gfn + index instead of using sp->shadowed_translation[] (or sp->gfns[]
in older kernels). It therefore fails to remove the recorded entry.
When the memslot is dropped the shadow page is freed but the rmap
entry survives, as in the scenario that was already fixed. Code that
later walks that gfn (dirty logging, MMU notifier invalidation, and
so on) dereferences an sptep that lies in the freed page, causing the
use-after-free.
CVSS Score
8.8
EPSS Score
0.009
Published
2026-07-04
In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gem: Fix phys BO pread/pwrite with offset
sg_page() returns struct page pointer not (void *) so the scaling
of pread/pwrite is wrong for phys BO and wrong parts of BO would be
accessed if non-zero offset is used.
Last impacted platform with overlay or cursor planes using phys
mapping was Gen3/945G/Lakeport.
(cherry picked from commit 3e49a2f85070b2fb672c1e0fdba281a4ea3aebe6)
CVSS Score
7.8
EPSS Score
0.001
Published
2026-07-01
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conntrack: destroy stale expectfn expectations on unregister
NAT helpers such as nf_nat_h323 store a raw pointer to module text in
exp->expectfn (e.g. ip_nat_q931_expect). nf_ct_helper_expectfn_unregister()
only unlinks the callback descriptor and never walks the expectation table,
so an expectation pending at module removal survives with a dangling
exp->expectfn into freed module text.
When the expected connection arrives, init_conntrack() invokes
exp->expectfn(), now a stale pointer into the unloaded module. Reproduced
on a KASAN build by loading the H.323 helpers, creating a Q.931
expectation, unloading nf_nat_h323, then connecting to the expected port:
Oops: int3: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:0xffffffffa06102d1
init_conntrack.isra.0 (net/netfilter/nf_conntrack_core.c:1862)
nf_conntrack_in (net/netfilter/nf_conntrack_core.c:2049)
ipv4_conntrack_local (net/netfilter/nf_conntrack_proto.c:223)
nf_hook_slow (net/netfilter/core.c:619)
__ip_local_out (net/ipv4/ip_output.c:120)
__tcp_transmit_skb (net/ipv4/tcp_output.c:1715)
tcp_connect (net/ipv4/tcp_output.c:4374)
tcp_v4_connect (net/ipv4/tcp_ipv4.c:345)
__sys_connect (net/socket.c:2167)
Modules linked in: nf_conntrack_h323 [last unloaded: nf_nat_h323]
Reaching the dangling state requires CAP_SYS_MODULE in the initial user
namespace to remove a NAT helper that still has live expectations, so this
is a robustness fix; leaving an expectation pointing at freed text is wrong
regardless.
Add nf_ct_helper_expectfn_destroy(), which walks the expectation table and
drops every expectation whose ->expectfn matches the descriptor being torn
down. Call it from each NAT helper's exit path after the existing RCU grace
period, so no expectation outlives the code it points at and no extra
synchronize_rcu() is introduced. With the fix, the same reproducer runs to
completion without the Oops.
CVSS Score
5.5
EPSS Score
0.001
Published
2026-07-01