| ID |
CVE-2025-38523
|
| Sažetak |
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. |
| Reference |
|
| CVSS |
| Base: | 5.5 |
| Impact: | 3.6 |
| Exploitability: | 1.8 |
|
| Pristup |
| Vektor | Složenost | Autentikacija |
| LOCAL |
LOW |
LOW |
|
| Impact |
| Povjerljivost | Cjelovitost | Dostupnost |
| NONE |
NONE |
HIGH |
|
| CVSS vektor |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Zadnje važnije ažuriranje |
18-11-2025 - 21:53 |
| Objavljeno |
16-08-2025 - 12:15 |
