CVE-2026-23205

In the Linux kernel, the following vulnerability has been resolved:

smb/client: fix memory leak in smb2openfile()

Reproducer:

1. server: directories are exported read-only
2. client: mount -t cifs //${server_ip}/export /mnt
3. client: dd if=/dev/zero of=/mnt/file bs=512 count=1000 oflag=direct
4. client: umount /mnt
5. client: sleep 1
6. client: modprobe -r cifs

The error message is as follows:

============================================================================= BUG cifssmallrq (Not tainted): Objects remaining on __kmemcacheshutdown()

Object 0x00000000d47521be @offset=14336 ... WARNING: mm/slub.c:1251 at __kmemcacheshutdown+0x34e/0x440, CPU#0: modprobe/1577 ... Call Trace: <TASK> kmemcachedestroy+0x94/0x190 cifsdestroyrequestbufs+0x3e/0x50 [cifs] cleanupmodule+0x4e/0x540 [cifs] __sesysdelete_module+0x278/0x400 _x64sysdeletemodule+0x5f/0x70 x64syscall+0x2299/0x2ff0 dosyscall64+0x89/0x350 entrySYSCALL64afterhwframe+0x76/0x7e ... kmemcachedestroy cifssmallrq: Slab cache still has objects when called from cifsdestroyrequestbufs+0x3e/0x50 [cifs] WARNING: mm/slabcommon.c:532 at kmemcachedestroy+0x16b/0x190, CPU#0: modprobe/1577