5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Arnaud Lecomte contact@arnaud-lcm.com
[ Upstream commit c214006856ff52a8ff17ed8da52d50601d54f9ce ]
When computing the tree index in dbAllocAG, we never check if we are out of bounds realative to the size of the stree. This could happen in a scenario where the filesystem metadata are corrupted.
Reported-by: syzbot+cffd18309153948f3c3e@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cffd18309153948f3c3e Tested-by: syzbot+cffd18309153948f3c3e@syzkaller.appspotmail.com Signed-off-by: Arnaud Lecomte contact@arnaud-lcm.com Signed-off-by: Dave Kleikamp dave.kleikamp@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/jfs/jfs_dmap.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index 15f885d2fa3d..17c4e7bdf283 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -1457,6 +1457,12 @@ dbAllocAG(struct bmap * bmp, int agno, s64 nblocks, int l2nb, s64 * results) (1 << (L2LPERCTL - (bmp->db_agheight << 1))) / bmp->db_agwidth; ti = bmp->db_agstart + bmp->db_agwidth * (agno & (agperlev - 1));
+ if (ti < 0 || ti >= le32_to_cpu(dcp->nleafs)) { + jfs_error(bmp->db_ipbmap->i_sb, "Corrupt dmapctl page\n"); + release_metapage(mp); + return -EIO; + } + /* dmap control page trees fan-out by 4 and a single allocation * group may be described by 1 or 2 subtrees within the ag level * dmap control page, depending upon the ag size. examine the ag's