Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server re-repick on subrequest retry When a subrequest is marked for needing retry, netfs will call cifs_prepare_write() which will make cifs repick the server for the op before renegotiating credits; it then calls cifs_issue_write() which invokes smb2_async_writev() - which re-repicks the server. If a different server is then selected, this causes the increment of server->in_flight to happen against one record and the decrement to happen against another, leading to misaccounting. Fix this by just removing the repick code in smb2_async_writev(). As this is only called from netfslib-driven code, cifs_prepare_write() should always have been called first, and so server should never be NULL and the preparatory step is repeated in the event that we do a retry. The problem manifests as a warning looking something like: WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Which may be triggered by a number of different xfstests running against an Azure server in multichannel mode. generic/249 seems the most repeatable, but generic/215, generic/249 and generic/308 may also show it.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 3ee1a1fc39819906f04d6c62c180e760cd3a689d before b1d0a566769b6fb3795b5289fc1daf9e0638d97a; affected 3ee1a1fc39819906f04d6c62c180e760cd3a689d before de40579b903883274fe203865f29d66b168b7236 |
| Linux / Linux | affected 6.10; unaffected 0 before 6.10; unaffected 6.10.1 through 6.10.*; unaffected 6.11 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/b1d0a566769b6fb3795b5289fc1daf9e0638d97a
- https://git.kernel.org/stable/c/de40579b903883274fe203865f29d66b168b7236
ADP enrichment
No English description supplied.
No references supplied.