From: Paulo Alcantara pc@manguebit.com

commit 69ccf040acddf33a3a85ec0f6b45ef84b0f7ec29 upstream.

Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

Cc: stable@vger.kernel.org # 5.4 Signed-off-by: Paulo Alcantara (Red Hat) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com [ chanho: Backported to v5.4.y, misc.c was moved from fs/cifs to fs/smb/client ] Signed-off-by: Chanho Min chanho.min@lge.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/cifs/misc.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index db1fcdedf289a..4d838d7db7b57 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -473,6 +473,8 @@ is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv) spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &srv->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); if (tcon->tid != buf->Tid)