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
@@ -1009,6 +1009,10 @@ 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;
