From: Paulo Alcantara <pc@xxxxxxxxxxxxx>
commit d3da25c5ac84430f89875ca7485a3828150a7e0a upstream.
Skip sessions that are being teared down (status == SES_EXITING) to
avoid UAF.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Paulo Alcantara (Red Hat) <pc@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
[ cifs_debug.c was moved from fs/cifs to fs/smb/client since
38c8a9a52082 ("smb: move client and server files to common directory fs/smb").
The cifs_ses_exiting() was introduced to cifs_debug.c since
ca545b7f0823 ("smb: client: fix potential UAF in cifs_debug_files_proc_show()").
and the SES_EXITING in cifs_ses_exiting() instead of CifsExiting since
dd3cd8709ed5 ("cifs: use new enum for ses_status").
The ses_lock in cifs_ses_exiting() was introduced in commmit d7d7a66aacd6
("cifs: avoid use of global locks for high contention data"), on 5.15/5.10,
there is a global lock take care of ses->status.
So use "if (ses->status == CifsExiting)" instead of "if (cifs_ses_exiting(ses))" ]
Signed-off-by: Xiangyu Chen <xiangyu.chen@xxxxxxxxxxxxx>
Signed-off-by: He Zhe <zhe.he@xxxxxxxxxxxxx>
---
Try to merge commit d3da25c5ac84430f89875ca7485a3828150a7e0a to 5.15
Verified the code compile on linux 5.15
---
fs/cifs/cifs_debug.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index e7501533c2ec..ce02cc71e117 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -528,6 +528,8 @@ static ssize_t cifs_stats_proc_write(struct file *file,
list_for_each(tmp2, &server->smb_ses_list) {
ses = list_entry(tmp2, struct cifs_ses,
smb_ses_list);
+ if (ses->status == CifsExiting)
+ continue;
list_for_each(tmp3, &ses->tcon_list) {
tcon = list_entry(tmp3,
struct cifs_tcon,
--
2.25.1
