jfs: upper bound check of tree index in dbAllocAG

[ Upstream commit c214006856 ]

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>
This commit is contained in:
Arnaud Lecomte 2025-04-24 00:13:51 +02:00 committed by Greg Kroah-Hartman
parent 78989af5bb
commit 173cfd741a

View File

@ -1389,6 +1389,12 @@ 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