From: Bob Peterson <[email protected]> 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: [email protected] Signed-off-by: Bob Peterson <[email protected]> Signed-off-by: Andreas Gruenbacher <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/gfs2/rgrp.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -990,6 +990,10 @@ 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;
