From: Nihar Chaithanya niharchaithanya@gmail.com
[ Upstream commit a174706ba4dad895c40b1d2277bade16dfacdcd9 ]
When the value of lp is 0 at the beginning of the for loop, it will become negative in the next assignment and we should bail out.
Reported-by: syzbot+412dea214d8baa3f7483@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=412dea214d8baa3f7483 Tested-by: syzbot+412dea214d8baa3f7483@syzkaller.appspotmail.com Signed-off-by: Nihar Chaithanya niharchaithanya@gmail.com Signed-off-by: Dave Kleikamp dave.kleikamp@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/jfs/jfs_dmap.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c index 30a56c37d9ecf..6509102e581a1 100644 --- a/fs/jfs/jfs_dmap.c +++ b/fs/jfs/jfs_dmap.c @@ -2891,6 +2891,9 @@ static void dbAdjTree(dmtree_t *tp, int leafno, int newval, bool is_ctl) /* bubble the new value up the tree as required. */ for (k = 0; k < le32_to_cpu(tp->dmt_height); k++) { + if (lp == 0) + break; + /* get the index of the first leaf of the 4 leaf * group containing the specified leaf (leafno). */