From: Paulo Alcantara pc@manguebit.com

commit 58acd1f497162e7d282077f816faa519487be045 upstream.

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

Cc: stable@vger.kernel.org Signed-off-by: Paulo Alcantara (Red Hat) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com [This patch removes lock/unlock operation in routine cifs_dump_full_key() 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@windriver.com Signed-off-by: He Zhe zhe.he@windriver.com --- Verified the build test --- fs/cifs/ioctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c index 71883ba9e567..e846c18b71d2 100644 --- a/fs/cifs/ioctl.c +++ b/fs/cifs/ioctl.c @@ -232,7 +232,8 @@ static int cifs_dump_full_key(struct cifs_tcon *tcon, struct smb3_full_key_debug spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(server_it, &cifs_tcp_ses_list, tcp_ses_list) { list_for_each_entry(ses_it, &server_it->smb_ses_list, smb_ses_list) { - if (ses_it->Suid == out.session_id) { + if (ses_it->status != CifsExiting && + ses_it->Suid == out.session_id) { ses = ses_it; /* * since we are using the session outside the crit