From: Arnaud Lecomte Date: Wed, 23 Apr 2025 22:13:51 +0000 (+0200) Subject: jfs: upper bound check of tree index in dbAllocAG X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c214006856ff52a8ff17ed8da52d50601d54f9ce;p=thirdparty%2Flinux.git jfs: upper bound check of tree index in dbAllocAG 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 Signed-off-by: Dave Kleikamp --- diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index 35e063c9f3a42..5080d59089bd7 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -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