Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()
After this commit (e2b76ab8b5c9 "ksmbd: add support for read compound"),
response buffer management was changed to use dynamic iov array.
In the new design, smb2_calc_max_out_buf_len() expects the second
argument (hdr2_len) to be the offset of ->Buffer field in the
response structure, not a hardcoded magic number.
Fix the remaining call sites to use the correct offsetof() value.
CVSS Score
9.8
EPSS Score
0.001
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: always keep track of remap prev/next
During 3D workload, user is reporting hitting:
[ 413.361679] WARNING: drivers/gpu/drm/xe/xe_vm.c:1217 at vm_bind_ioctl_ops_unwind+0x1e2/0x2e0 [xe], CPU#7: vkd3d_queue/9925
[ 413.361944] CPU: 7 UID: 1000 PID: 9925 Comm: vkd3d_queue Kdump: loaded Not tainted 7.0.0-070000rc3-generic #202603090038 PREEMPT(lazy)
[ 413.361949] RIP: 0010:vm_bind_ioctl_ops_unwind+0x1e2/0x2e0 [xe]
[ 413.362074] RSP: 0018:ffffd4c25c3df930 EFLAGS: 00010282
[ 413.362077] RAX: 0000000000000000 RBX: ffff8f3ee817ed10 RCX: 0000000000000000
[ 413.362078] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 413.362079] RBP: ffffd4c25c3df980 R08: 0000000000000000 R09: 0000000000000000
[ 413.362081] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8f41fbf99380
[ 413.362082] R13: ffff8f3ee817e968 R14: 00000000ffffffef R15: ffff8f43d00bd380
[ 413.362083] FS: 00000001040ff6c0(0000) GS:ffff8f4696d89000(0000) knlGS:00000000330b0000
[ 413.362085] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
[ 413.362086] CR2: 00007ddfc4747000 CR3: 00000002e6262005 CR4: 0000000000f72ef0
[ 413.362088] PKRU: 55555554
[ 413.362089] Call Trace:
[ 413.362092] <TASK>
[ 413.362096] xe_vm_bind_ioctl+0xa9a/0xc60 [xe]
Which seems to hint that the vma we are re-inserting for the ops unwind
is either invalid or overlapping with something already inserted in the
vm. It shouldn't be invalid since this is a re-insertion, so must have
worked before. Leaving the likely culprit as something already placed
where we want to insert the vma.
Following from that, for the case where we do something like a rebind in
the middle of a vma, and one or both mapped ends are already compatible,
we skip doing the rebind of those vma and set next/prev to NULL. As well
as then adjust the original unmap va range, to avoid unmapping the ends.
However, if we trigger the unwind path, we end up with three va, with
the two ends never being removed and the original va range in the middle
still being the shrunken size.
If this occurs, one failure mode is when another unwind op needs to
interact with that range, which can happen with a vector of binds. For
example, if we need to re-insert something in place of the original va.
In this case the va is still the shrunken version, so when removing it
and then doing a re-insert it can overlap with the ends, which were
never removed, triggering a warning like above, plus leaving the vm in a
bad state.
With that, we need two things here:
1) Stop nuking the prev/next tracking for the skip cases. Instead
relying on checking for skip prev/next, where needed. That way on the
unwind path, we now correctly remove both ends.
2) Undo the unmap va shrinkage, on the unwind path. With the two ends
now removed the unmap va should expand back to the original size again,
before re-insertion.
v2:
- Update the explanation in the commit message, based on an actual IGT of
triggering this issue, rather than conjecture.
- Also undo the unmap shrinkage, for the skip case. With the two ends
now removed, the original unmap va range should expand back to the
original range.
v3:
- Track the old start/range separately. vma_size/start() uses the va
info directly.
(cherry picked from commit aec6969f75afbf4e01fd5fb5850ed3e9c27043ac)
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
xfrm: iptfs: validate inner IPv4 header length in IPTFS payload
Add validation of the inner IPv4 packet tot_len and ihl fields parsed
from decrypted IPTFS payloads in __input_process_payload(). A crafted
ESP packet containing an inner IPv4 header with tot_len=0 causes an
infinite loop: iplen=0 leads to capturelen=min(0, remaining)=0, so the
data offset never advances and the while(data < tail) loop never
terminates, spinning forever in softirq context.
Reject inner IPv4 packets where tot_len < ihl*4 or ihl*4 < sizeof(struct
iphdr), which catches both the tot_len=0 case and malformed ihl values.
The normal IP stack performs this validation in ip_rcv_core(), but IPTFS
extracts and processes inner packets before they reach that layer.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
media: mc, v4l2: serialize REINIT and REQBUFS with req_queue_mutex
MEDIA_REQUEST_IOC_REINIT can run concurrently with VIDIOC_REQBUFS(0)
queue teardown paths. This can race request object cleanup against vb2
queue cancellation and lead to use-after-free reports.
We already serialize request queueing against STREAMON/OFF with
req_queue_mutex. Extend that serialization to REQBUFS, and also take
the same mutex in media_request_ioctl_reinit() so REINIT is in the
same exclusion domain.
This keeps request cleanup and queue cancellation from running in
parallel for request-capable devices.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/sysfs: check contexts->nr in repeat_call_fn
damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(),
damon_sysfs_upd_schemes_stats(), and
damon_sysfs_upd_schemes_effective_quotas() without checking contexts->nr.
If nr_contexts is set to 0 via sysfs while DAMON is running, these
functions dereference contexts_arr[0] and cause a NULL pointer
dereference. Add the missing check.
For example, the issue can be reproduced using DAMON sysfs interface and
DAMON user-space tool (damo) [1] like below.
$ sudo damo start --refresh_interval 1s
$ echo 0 | sudo tee \
/sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]
Multiple sysfs command paths dereference contexts_arr[0] without first
verifying that kdamond->contexts->nr == 1. A user can set nr_contexts to
0 via sysfs while DAMON is running, causing NULL pointer dereferences.
In more detail, the issue can be triggered by privileged users like
below.
First, start DAMON and make contexts directory empty
(kdamond->contexts->nr == 0).
# damo start
# cd /sys/kernel/mm/damon/admin/kdamonds/0
# echo 0 > contexts/nr_contexts
Then, each of below commands will cause the NULL pointer dereference.
# echo update_schemes_stats > state
# echo update_schemes_tried_regions > state
# echo update_schemes_tried_bytes > state
# echo update_schemes_effective_quotas > state
# echo update_tuned_intervals > state
Guard all commands (except OFF) at the entry point of
damon_sysfs_handle_cmd().
CVSS Score
5.5
EPSS Score
0.0
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
xfs: stop reclaim before pushing AIL during unmount
The unmount sequence in xfs_unmount_flush_inodes() pushed the AIL while
background reclaim and inodegc are still running. This is broken
independently of any use-after-free issues - background reclaim and
inodegc should not be running while the AIL is being pushed during
unmount, as inodegc can dirty and insert inodes into the AIL during the
flush, and background reclaim can race to abort and free dirty inodes.
Reorder xfs_unmount_flush_inodes() to stop inodegc and cancel background
reclaim before pushing the AIL. Stop inodegc before cancelling
m_reclaim_work because the inodegc worker can re-queue m_reclaim_work
via xfs_inodegc_set_reclaimable.
CVSS Score
7.8
EPSS Score
0.0
Published
2026-04-22
In the Linux kernel, the following vulnerability has been resolved:
mm/pagewalk: fix race between concurrent split and refault
The splitting of a PUD entry in walk_pud_range() can race with a
concurrent thread refaulting the PUD leaf entry causing it to try walking
a PMD range that has disappeared.
An example and reproduction of this is to try reading numa_maps of a
process while VFIO-PCI is setting up DMA (specifically the
vfio_pin_pages_remote call) on a large BAR for that process.
This will trigger a kernel BUG:
vfio-pci 0000:03:00.0: enabling device (0000 -> 0002)
BUG: unable to handle page fault for address: ffffa23980000000
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
...
RIP: 0010:walk_pgd_range+0x3b5/0x7a0
Code: 8d 43 ff 48 89 44 24 28 4d 89 ce 4d 8d a7 00 00 20 00 48 8b 4c 24
28 49 81 e4 00 00 e0 ff 49 8d 44 24 ff 48 39 c8 4c 0f 43 e3 <49> f7 06
9f ff ff ff 75 3b 48 8b 44 24 20 48 8b 40 28 48 85 c0 74
RSP: 0018:ffffac23e1ecf808 EFLAGS: 00010287
RAX: 00007f44c01fffff RBX: 00007f4500000000 RCX: 00007f44ffffffff
RDX: 0000000000000000 RSI: 000ffffffffff000 RDI: ffffffff93378fe0
RBP: ffffac23e1ecf918 R08: 0000000000000004 R09: ffffa23980000000
R10: 0000000000000020 R11: 0000000000000004 R12: 00007f44c0200000
R13: 00007f44c0000000 R14: ffffa23980000000 R15: 00007f44c0000000
FS: 00007fe884739580(0000) GS:ffff9b7d7a9c0000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffa23980000000 CR3: 000000c0650e2005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<TASK>
__walk_page_range+0x195/0x1b0
walk_page_vma+0x62/0xc0
show_numa_map+0x12b/0x3b0
seq_read_iter+0x297/0x440
seq_read+0x11d/0x140
vfs_read+0xc2/0x340
ksys_read+0x5f/0xe0
do_syscall_64+0x68/0x130
? get_page_from_freelist+0x5c2/0x17e0
? mas_store_prealloc+0x17e/0x360
? vma_set_page_prot+0x4c/0xa0
? __alloc_pages_noprof+0x14e/0x2d0
? __mod_memcg_lruvec_state+0x8d/0x140
? __lruvec_stat_mod_folio+0x76/0xb0
? __folio_mod_stat+0x26/0x80
? do_anonymous_page+0x705/0x900
? __handle_mm_fault+0xa8d/0x1000
? __count_memcg_events+0x53/0xf0
? handle_mm_fault+0xa5/0x360
? do_user_addr_fault+0x342/0x640
? arch_exit_to_user_mode_prepare.constprop.0+0x16/0xa0
? irqentry_exit_to_user_mode+0x24/0x100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fe88464f47e
Code: c0 e9 b6 fe ff ff 50 48 8d 3d be 07 0b 00 e8 69 01 02 00 66 0f 1f
84 00 00 00 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00
f0 ff ff 77 5a c3 66 0f 1f 84 00 00 00 00 00 48 83 ec 28
RSP: 002b:00007ffe6cd9a9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fe88464f47e
RDX: 0000000000020000 RSI: 00007fe884543000 RDI: 0000000000000003
RBP: 00007fe884543000 R08: 00007fe884542010 R09: 0000000000000000
R10: fffffffffffffbc5 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000
</TASK>
Fix this by validating the PUD entry in walk_pmd_range() using a stable
snapshot (pudp_get()). If the PUD is not present or is a leaf, retry the
walk via ACTION_AGAIN instead of descending further. This mirrors the
retry logic in walk_pte_range(), which lets walk_pmd_range() retry if the
PTE is not being got by pte_offset_map_lock().
CVSS Score
4.7
EPSS Score
0.0
Published
2026-04-22
An RPZ sent by a malicious authoritative server can result in a null pointer dereference, caused by a missing consistency check and leading to a denial of service.
CVSS Score
4.4
EPSS Score
0.0
Published
2026-04-22
If you use the zoneToCache function with a malicious authoritative server, an attacker can send a zone that result in a null pointer dereference, caused by a missing consistency check and leading to a denial of service.
CVSS Score
4.4
EPSS Score
0.0
Published
2026-04-22