FAILED: patch "[PATCH] cifs: fix integer overflow in match_server()" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 2510859475d7f46ed7940db0853f3342bf1b65ee
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025041759-pristine-hungry-5acf@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 2510859475d7f46ed7940db0853f3342bf1b65ee Mon Sep 17 00:00:00 2001
From: Roman Smirnov <r.smirnov@omp.ru>
Date: Mon, 31 Mar 2025 11:22:49 +0300
Subject: [PATCH] cifs: fix integer overflow in match_server()

The echo_interval is not limited in any way during mounting,
which makes it possible to write a large number to it. This can
cause an overflow when multiplying ctx->echo_interval by HZ in
match_server().

Add constraints for echo_interval to smb3_fs_context_parse_param().

Found by Linux Verification Center (linuxtesting.org) with Svace.

Fixes: adfeb3e00e8e1 ("cifs: Make echo interval tunable")
Cc: stable@vger.kernel.org
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index bdb762d398af..9c3ded0cf006 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -1383,6 +1383,11 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 		ctx->closetimeo = HZ * result.uint_32;
 		break;
 	case Opt_echo_interval:
+		if (result.uint_32 < SMB_ECHO_INTERVAL_MIN ||
+		    result.uint_32 > SMB_ECHO_INTERVAL_MAX) {
+			cifs_errorf(fc, "echo interval is out of bounds\n");
+			goto cifs_parse_mount_err;
+		}
 		ctx->echo_interval = result.uint_32;
 		break;
 	case Opt_snapshot: