+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Valentin Vidic <vvidic@valentin-vidic.from.hr>
+Date: Mon, 27 Sep 2021 17:44:59 +0200
+Subject: [PATCH] ocfs2: mount fails with buffer overflow in strlen
+
+Starting with kernel v5.11 mouting an ocfs2 filesystem with either o2cb
+or pcmk cluster stack fails with the trace below. Problem seems to be
+that strings for cluster stack and cluster name are not guaranteed to be
+null terminated in the disk representation, while strlcpy assumes that
+the source string is always null terminated. This causes a read outside
+of the source string triggering the buffer overflow detection.
+
+detected buffer overflow in strlen
+------------[ cut here ]------------
+kernel BUG at lib/string.c:1149!
+invalid opcode: 0000 [#1] SMP PTI
+CPU: 1 PID: 910 Comm: mount.ocfs2 Not tainted 5.14.0-1-amd64 #1
+ Debian 5.14.6-2
+RIP: 0010:fortify_panic+0xf/0x11
+...
+Call Trace:
+ ocfs2_initialize_super.isra.0.cold+0xc/0x18 [ocfs2]
+ ocfs2_fill_super+0x359/0x19b0 [ocfs2]
+ mount_bdev+0x185/0x1b0
+ ? ocfs2_remount+0x440/0x440 [ocfs2]
+ legacy_get_tree+0x27/0x40
+ vfs_get_tree+0x25/0xb0
+ path_mount+0x454/0xa20
+ __x64_sys_mount+0x103/0x140
+ do_syscall_64+0x3b/0xc0
+ entry_SYSCALL_64_after_hwframe+0x44/0xae
+
+Signed-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
+Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
+---
+ fs/ocfs2/super.c | 10 ++++++----
+ 1 file changed, 6 insertions(+), 4 deletions(-)
+
+diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
+index c86bd4e60e20..1dea535224df 100644
+--- a/fs/ocfs2/super.c
++++ b/fs/ocfs2/super.c
+@@ -2169,9 +2169,10 @@ static int ocfs2_initialize_super(struct super_block *sb,
+ if (ocfs2_clusterinfo_valid(osb)) {
+ osb->osb_stackflags =
+ OCFS2_RAW_SB(di)->s_cluster_info.ci_stackflags;
+- strlcpy(osb->osb_cluster_stack,
++ memcpy(osb->osb_cluster_stack,
+ OCFS2_RAW_SB(di)->s_cluster_info.ci_stack,
+- OCFS2_STACK_LABEL_LEN + 1);
++ OCFS2_STACK_LABEL_LEN);
++ osb->osb_cluster_stack[OCFS2_STACK_LABEL_LEN] = '\0';
+ if (strlen(osb->osb_cluster_stack) != OCFS2_STACK_LABEL_LEN) {
+ mlog(ML_ERROR,
+ "couldn't mount because of an invalid "
+@@ -2180,9 +2181,10 @@ static int ocfs2_initialize_super(struct super_block *sb,
+ status = -EINVAL;
+ goto bail;
+ }
+- strlcpy(osb->osb_cluster_name,
++ memcpy(osb->osb_cluster_name,
+ OCFS2_RAW_SB(di)->s_cluster_info.ci_cluster,
+- OCFS2_CLUSTER_NAME_LEN + 1);
++ OCFS2_CLUSTER_NAME_LEN);
++ osb->osb_cluster_name[OCFS2_CLUSTER_NAME_LEN] = '\0';
+ } else {
+ /* The empty string is identical with classic tools that
+ * don't know about s_cluster_info. */