From: Paulo Alcantara <pc@xxxxxxxxxxxxx> commit ca545b7f0823f19db0f1148d59bc5e1a56634502 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> [ This patch removes lock/unlock operation in routine cifs_ses_exiting() for ses_lock is not present in v5.15 and not ported yet. ses->status is protected by a global lock, cifs_tcp_ses_lock, in v5.15. ] Signed-off-by: Jianqi Ren <jianqi.ren.cn@xxxxxxxxxxxxx> Signed-off-by: He Zhe <zhe.he@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/cifs/cifs_debug.c | 2 ++ fs/cifs/cifsglob.h | 8 ++++++++ 2 files changed, 10 insertions(+) --- a/fs/cifs/cifs_debug.c +++ b/fs/cifs/cifs_debug.c @@ -183,6 +183,8 @@ static int cifs_debug_files_proc_show(st list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) { list_for_each(tmp, &server->smb_ses_list) { ses = list_entry(tmp, struct cifs_ses, smb_ses_list); + if (cifs_ses_exiting(ses)) + continue; list_for_each(tmp1, &ses->tcon_list) { tcon = list_entry(tmp1, struct cifs_tcon, tcon_list); spin_lock(&tcon->open_file_lock); --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -2041,4 +2041,12 @@ static inline struct scatterlist *cifs_s return sg; } +static inline bool cifs_ses_exiting(struct cifs_ses *ses) +{ + bool ret; + + ret = ses->status == CifsExiting; + return ret; +} + #endif /* _CIFS_GLOB_H */ Patches currently in stable-queue which might be from pc@xxxxxxxxxxxxx are queue-5.15/smb-client-fix-potential-uaf-in-cifs_debug_files_proc_show.patch