In the Linux kernel, the following vulnerability has been resolved:
NFSv4/flexfiles: reject zero filehandle version count
ff_layout_alloc_lseg() decodes the filehandle-version array count
from the flexfiles layout body. The value is used as the count for
kzalloc_objs(), and the current code only rejects NULL.
A zero count yields ZERO_SIZE_PTR, which can be stored in
dss_info->fh_versions even though later flexfiles paths assume that at
least one filehandle version exists.
Reject fh_count == 0 before the allocation, matching the existing zero
version_count validation in the flexfiles GETDEVICEINFO parser.
A QEMU/KASAN run with a malformed flexfiles layout hit:
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750
ff_layout_encode_layoutreturn+0x683/0x970
nfs4_xdr_enc_layoutreturn+0x278/0x3a0
Kernel panic - not syncing: Fatal exception
The patched kernel rejects the malformed layout without KASAN/oops/panic,
and a valid fh_count=1 regression still opens, reads, and unmounts cleanly.
References
Configurations
Configuration 1 (hide)
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History
29 Jul 2026, 20:33
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/18cc6d57a14fa65ab2a2b52279f549041c4bc9cf - Patch | |
| References | () https://git.kernel.org/stable/c/2131ed64b767ffa8bcdb3677d90f3964e39aabc8 - Patch | |
| References | () https://git.kernel.org/stable/c/2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2 - Patch | |
| References | () https://git.kernel.org/stable/c/7779c85028a0676fb190cde4f0c540f4f8e97761 - Patch | |
| References | () https://git.kernel.org/stable/c/9033591535c066726f5b505126ccb4068b98fa4f - Patch | |
| References | () https://git.kernel.org/stable/c/be7829715e341b42846437dd9e721005db59f0cc - Patch | |
| References | () https://git.kernel.org/stable/c/d8c90c7cc061265d5f2813a1f5c82ef2f4707e67 - Patch | |
| References | () https://git.kernel.org/stable/c/eeabb9020721db6bc132e68eeae380b8d4fb4b04 - Patch | |
| CWE | CWE-476 | |
| First Time |
Linux linux Kernel
Linux |
|
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
24 Jul 2026, 15:18
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
20 Jul 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.5 |
19 Jul 2026, 12:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-07-19 12:16
Updated : 2026-07-29 20:33
NVD link : CVE-2026-53392
Mitre link : CVE-2026-53392
CVE.ORG link : CVE-2026-53392
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-476
NULL Pointer Dereference
