[PATCH 6.1.y] smb: client: fix potential UAF in cifs_dump_full_key() - Linux-stable-mirror

11 Dec 2024

From: Paulo Alcantara pc@manguebit.com
[ Upstream commit 58acd1f497162e7d282077f816faa519487be045 ]
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
Signed-off-by: Jianqi Ren jianqi.ren.cn@windriver.com
---
 fs/smb/client/ioctl.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/smb/client/ioctl.c b/fs/smb/client/ioctl.c
index ae9905e2b9d4..7402070b7a06 100644
--- a/fs/smb/client/ioctl.c
+++ b/fs/smb/client/ioctl.c
@@ -246,7 +246,9 @@ 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) {
+				spin_lock(&ses_it->ses_lock);
+				if (ses_it->ses_status != SES_EXITING &&
+				    ses_it->Suid == out.session_id) {
    				ses = ses_it;
    				/*
    				 * since we are using the session outside the crit
@@ -254,9 +256,11 @@ static int cifs_dump_full_key(struct cifs_tcon *tcon, struct smb3_full_key_debug
    				 * so increment its refcount
    				 */
    				ses->ses_count++;
+					spin_unlock(&ses_it->ses_lock);
    				found = true;
    				goto search_end;
    			}
+				spin_unlock(&ses_it->ses_lock);
    		}
    	}
 search_end:
-- 
2.25.1



    