From 204c0300c4e99707e9fb6e57840aa1127060e63f Mon Sep 17 00:00:00 2001
From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Fri, 26 Aug 2022 15:12:17 +0200
Subject: [PATCH] gfs2: Switch from strlcpy to strscpy
Git-commit: 204c0300c4e99707e9fb6e57840aa1127060e63f
Patch-mainline: v6.1-rc1
References: git-fixes

Switch from strlcpy to strscpy and make sure that @count is the size of
the smaller of the source and destination buffers.  This prevents
reading beyond the end of the source buffer when the source string isn't
null terminated.

Found by a modified version of syzkaller.

Suggested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Anthony Iliopoulos <ailiop@suse.com>

---
 fs/gfs2/ops_fstype.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 549879929c84..236b59ef93b6 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -381,8 +381,10 @@ static int init_names(struct gfs2_sbd *sdp, int silent)
 	if (!table[0])
 		table = sdp->sd_vfs->s_id;
 
-	strlcpy(sdp->sd_proto_name, proto, GFS2_FSNAME_LEN);
-	strlcpy(sdp->sd_table_name, table, GFS2_FSNAME_LEN);
+	BUILD_BUG_ON(GFS2_LOCKNAME_LEN > GFS2_FSNAME_LEN);
+
+	strscpy(sdp->sd_proto_name, proto, GFS2_LOCKNAME_LEN);
+	strscpy(sdp->sd_table_name, table, GFS2_LOCKNAME_LEN);
 
 	table = sdp->sd_table_name;
 	while ((table = strchr(table, '/')))
@@ -1439,13 +1441,13 @@ static int gfs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
 
 	switch (o) {
 	case Opt_lockproto:
-		strlcpy(args->ar_lockproto, param->string, GFS2_LOCKNAME_LEN);
+		strscpy(args->ar_lockproto, param->string, GFS2_LOCKNAME_LEN);
 		break;
 	case Opt_locktable:
-		strlcpy(args->ar_locktable, param->string, GFS2_LOCKNAME_LEN);
+		strscpy(args->ar_locktable, param->string, GFS2_LOCKNAME_LEN);
 		break;
 	case Opt_hostdata:
-		strlcpy(args->ar_hostdata, param->string, GFS2_LOCKNAME_LEN);
+		strscpy(args->ar_hostdata, param->string, GFS2_LOCKNAME_LEN);
 		break;
 	case Opt_spectator:
 		args->ar_spectator = 1;
-- 
2.43.0