From 3d340b684dcec5e34efc470227cd1c7d2df121ad Mon Sep 17 00:00:00 2001 From: Hoi Pok Wu Date: Tue, 25 Oct 2022 23:20:45 +0800 Subject: [PATCH] fs: jfs: fix shift-out-of-bounds in dbDiscardAG [ Upstream commit 25e70c6162f207828dd405b432d8f2a98dbf7082 ] This should be applied to most URSAN bugs found recently by syzbot, by guarding the dbMount. As syzbot feeding rubbish into the bmap descriptor. Signed-off-by: Hoi Pok Wu Signed-off-by: Dave Kleikamp Signed-off-by: Sasha Levin --- fs/jfs/jfs_dmap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index e1cbfbb60303..765838578a72 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -198,6 +198,11 @@ int dbMount(struct inode *ipbmap) goto err_release_metapage; } + if (((bmp->db_mapsize - 1) >> bmp->db_agl2size) > MAXAG) { + err = -EINVAL; + goto err_release_metapage; + } + for (i = 0; i < MAXAG; i++) bmp->db_agfree[i] = le64_to_cpu(dbmp_le->dn_agfree[i]); bmp->db_agsize = le64_to_cpu(dbmp_le->dn_agsize);