The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 605b249ea96770ac4fac4b8510a99e0f8442be5e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025031654-posh-culture-2f79@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 605b249ea96770ac4fac4b8510a99e0f8442be5e Mon Sep 17 00:00:00 2001 From: Henrique Carvalho henrique.carvalho@suse.com Date: Tue, 11 Mar 2025 15:23:59 -0300 Subject: [PATCH] smb: client: Fix match_session bug preventing session reuse

Fix a bug in match_session() that can causes the session to not be reused in some cases.

Reproduction steps:

mount.cifs //server/share /mnt/a -o credentials=creds mount.cifs //server/share /mnt/b -o credentials=creds,sec=ntlmssp cat /proc/fs/cifs/DebugData | grep SessionId | wc -l

mount.cifs //server/share /mnt/b -o credentials=creds,sec=ntlmssp mount.cifs //server/share /mnt/a -o credentials=creds cat /proc/fs/cifs/DebugData | grep SessionId | wc -l

Cc: stable@vger.kernel.org Reviewed-by: Enzo Matsumiya ematsumiya@suse.de Signed-off-by: Henrique Carvalho henrique.carvalho@suse.com Signed-off-by: Steve French stfrench@microsoft.com

diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index f917de020dd5..73f93a35eedd 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -1825,9 +1825,8 @@ static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx, bool match_super) { - if (ctx->sectype != Unspecified && - ctx->sectype != ses->sectype) - return 0; + struct TCP_Server_Info *server = ses->server; + enum securityEnum ctx_sec, ses_sec;

if (!match_super && ctx->dfs_root_ses != ses->dfs_root_ses) return 0; @@ -1839,11 +1838,20 @@ static int match_session(struct cifs_ses *ses, if (ses->chan_max < ctx->max_channels) return 0;

- switch (ses->sectype) { + ctx_sec = server->ops->select_sectype(server, ctx->sectype); + ses_sec = server->ops->select_sectype(server, ses->sectype); + + if (ctx_sec != ses_sec) + return 0; + + switch (ctx_sec) { + case IAKerb: case Kerberos: if (!uid_eq(ctx->cred_uid, ses->cred_uid)) return 0; break; + case NTLMv2: + case RawNTLMSSP: default: /* NULL username means anonymous session */ if (ses->user_name == NULL) {