[PATCH AUTOSEL 6.11 165/244] jfs: check if leafidx greater than num leaves per dmap tree

Sasha Levin
2024-09-25T11:47:48Z

From: Edward Adam Davis <eadavis@qq.com>

[ Upstream commit d64ff0d2306713ff084d4b09f84ed1a8c75ecc32 ]

syzbot report a out of bounds in dbSplit, it because dmt_leafidx greater
than num leaves per dmap tree, add a checking for dmt_leafidx in dbFindLeaf.

Shaggy:
Modified sanity check to apply to control pages as well as leaf pages.

Reported-and-tested-by: syzbot+dca05492eff41f604890@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=dca05492eff41f604890
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/jfs/jfs_dmap.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index ccdfa38d7a682..53904e06d843b 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -2944,9 +2944,10 @@ static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl)
static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl)
{
int ti, n = 0, k, x = 0;
- int max_size;
+ int max_size, max_idx;

max_size = is_ctl ? CTLTREESIZE : TREESIZE;
+ max_idx = is_ctl ? LPERCTL : LPERDMAP;

/* first check the root of the tree to see if there is
* sufficient free space.
@@ -2978,6 +2979,8 @@ static int dbFindLeaf(dmtree_t *tp, int l2nb, int *leafidx, bool is_ctl)
*/
assert(n < 4);
}
+ if (le32_to_cpu(tp->dmt_leafidx) >= max_idx)
+ return -ENOSPC;

/* set the return to the leftmost leaf describing sufficient
* free space.
--
2.43.0