In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix the smbd_response slab to allow usercopy
The handling of received data in the smbdirect client code involves using
copy_to_iter() to copy data from the smbd_reponse struct's packet trailer
to a folioq buffer provided by netfslib that encapsulates a chunk of
pagecache.
If, however, CONFIG_HARDENED_USERCOPY=y, this will result in the checks
then performed in copy_to_iter() oopsing with something like the following:
CIFS: Attempting to mount //172.31.9.1/test
CIFS: VFS: RDMA transport established
usercopy: Kernel memory exposure attempt detected from SLUB object 'smbd_response_0000000091e24ea1' (offset 81, size 63)!
------------[ cut here ]------------
kernel BUG at mm/usercopy.c:102!
...
RIP: 0010:usercopy_abort+0x6c/0x80
...
Call Trace:
<TASK>
__check_heap_object+0xe3/0x120
__check_object_size+0x4dc/0x6d0
smbd_recv+0x77f/0xfe0 [cifs]
cifs_readv_from_socket+0x276/0x8f0 [cifs]
cifs_read_from_socket+0xcd/0x120 [cifs]
cifs_demultiplex_thread+0x7e9/0x2d50 [cifs]
kthread+0x396/0x830
ret_from_fork+0x2b8/0x3b0
ret_from_fork_asm+0x1a/0x30
The problem is that the smbd_response slab's packet field isn't marked as
being permitted for usercopy.
Fix this by passing parameters to kmem_slab_create() to indicate that
copy_to_iter() is permitted from the packet region of the smbd_response
slab objects, less the header space.
References
Configurations
Configuration 1 (hide)
|
History
18 Nov 2025, 21:53
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| References | () https://git.kernel.org/stable/c/43e7e284fc77b710d899569360ea46fa3374ae22 - Patch | |
| References | () https://git.kernel.org/stable/c/87dcc7e33fc3dcb8ed32333cec016528b5bb6ce4 - Patch | |
| References | () https://git.kernel.org/stable/c/f0dd353d47f7051afa98c6c60c7486831eb1a410 - Patch | |
| First Time |
Linux linux Kernel
Linux |
|
| CWE | CWE-1188 |
Information
Published : 2025-08-16 12:15
Updated : 2025-11-18 21:53
NVD link : CVE-2025-38523
Mitre link : CVE-2025-38523
CVE.ORG link : CVE-2025-38523
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-1188
Initialization of a Resource with an Insecure Default
