From 2510859475d7f46ed7940db0853f3342bf1b65ee Mon Sep 17 00:00:00 2001 From: Roman Smirnov 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 Signed-off-by: Steve French --- fs/smb/client/fs_context.c | 5 +++++ 1 file changed, 5 insertions(+) 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: -- 2.50.1