From: Andrew Price Date: Mon, 8 Oct 2018 12:52:43 +0000 (-0500) Subject: gfs2: Don't leave s_fs_info pointing to freed memory in init_sbd X-Git-Tag: v3.18.128~78 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e458d80f65425d9066b6579c7a363708e2138833;p=profile%2Fwearable%2Fplatform%2Fkernel%2Flinux-3.18-exynos7270.git gfs2: Don't leave s_fs_info pointing to freed memory in init_sbd commit 4c62bd9cea7bcf10292f7e4c57a2bca332942697 upstream. When alloc_percpu() fails, sdp gets freed but sb->s_fs_info still points to the same address. Move the assignment after that error check so that s_fs_info can only point to a valid sdp or NULL, which is checked for later in the error path, in gfs2_kill_super(). Reported-by: syzbot+dcb8b3587445007f5808@syzkaller.appspotmail.com Signed-off-by: Andrew Price Signed-off-by: Bob Peterson Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index a4569ca..a65ef66 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -71,13 +71,13 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb) if (!sdp) return NULL; - sb->s_fs_info = sdp; sdp->sd_vfs = sb; sdp->sd_lkstats = alloc_percpu(struct gfs2_pcpu_lkstats); if (!sdp->sd_lkstats) { kfree(sdp); return NULL; } + sb->s_fs_info = sdp; set_bit(SDF_NOJOURNALID, &sdp->sd_flags); gfs2_tune_init(&sdp->sd_tune);