gfs2: Fix inode height consistency check

[ Upstream commit cfcdb5bad34f600aed7613c3c1a5e618111f77b7 ]

The maximum allowed height of an inode's metadata tree depends on the
filesystem block size; it is lower for bigger-block filesystems.  When
reading in an inode, make sure that the height doesn't exceed the
maximum allowed height.

Arrays like sd_heightsize are sized to be big enough for any filesystem
block size; they will often be slightly bigger than what's needed for a
specific filesystem.

Reported-by: syzbot+45d4691b1ed3c48eba05@syzkaller.appspotmail.com
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 69106a1545fadac98bcfdb97cd4b8423f2be4067..092223a8b120177a24fa639f4c22344887442a62 100644 (file)
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -362,6 +362,7 @@ static int inode_go_demote_ok(const struct gfs2_glock *gl)
 
 static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
 {
+       struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        const struct gfs2_dinode *str = buf;
        struct timespec64 atime;
        u16 height, depth;
@@ -401,7 +402,7 @@ static int gfs2_dinode_in(struct gfs2_inode *ip, const void *buf)
        /* i_diskflags and i_eattr must be set before gfs2_set_inode_flags() */
        gfs2_set_inode_flags(&ip->i_inode);
        height = be16_to_cpu(str->di_height);
-       if (unlikely(height > GFS2_MAX_META_HEIGHT))
+       if (unlikely(height > sdp->sd_max_height))
                goto corrupt;
        ip->i_height = (u8)height;