This is a note to let you know that I've just added the patch titled
gfs2: check for empty rgrp tree in gfs2_ri_update
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gfs2-check-for-empty-rgrp-tree-in-gfs2_ri_update.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 778721510e84209f78e31e2ccb296ae36d623f5e Mon Sep 17 00:00:00 2001
From: Bob Peterson <rpeterso@xxxxxxxxxx>
Date: Tue, 24 Nov 2020 10:44:36 -0500
Subject: gfs2: check for empty rgrp tree in gfs2_ri_update
From: Bob Peterson <rpeterso@xxxxxxxxxx>
commit 778721510e84209f78e31e2ccb296ae36d623f5e upstream.
If gfs2 tries to mount a (corrupt) file system that has no resource
groups it still tries to set preferences on the first one, which causes
a kernel null pointer dereference. This patch adds a check to function
gfs2_ri_update so this condition is detected and reported back as an
error.
Reported-by: syzbot+e3f23ce40269a4c9053a@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Bob Peterson <rpeterso@xxxxxxxxxx>
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/gfs2/rgrp.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1000,6 +1000,10 @@ static int gfs2_ri_update(struct gfs2_in
if (error < 0)
return error;
+ if (RB_EMPTY_ROOT(&sdp->sd_rindex_tree)) {
+ fs_err(sdp, "no resource groups found in the file system.\n");
+ return -ENOENT;
+ }
set_rgrp_preferences(sdp);
sdp->sd_rindex_uptodate = 1;
Patches currently in stable-queue which might be from rpeterso@xxxxxxxxxx are
queue-4.9/gfs2-check-for-empty-rgrp-tree-in-gfs2_ri_update.patch
