diff options
| author | Cong Wang <xiyou.wangcong@gmail.com> | 2018-12-30 12:43:42 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-01-01 11:58:33 -0800 |
| commit | aff6db454599d62191aabc208930e891748e4322 (patch) | |
| tree | 1c26fd35a8fc7540bb81ca60fe96251c74e71b36 | |
| parent | 4087d2bc0d9469835f8d19d63a4a56739e5b8c5b (diff) | |
| download | linux-aff6db454599d62191aabc208930e891748e4322.tar.gz linux-aff6db454599d62191aabc208930e891748e4322.tar.bz2 linux-aff6db454599d62191aabc208930e891748e4322.zip | |
ptr_ring: wrap back ->producer in __ptr_ring_swap_queue()
__ptr_ring_swap_queue() tries to move pointers from the old
ring to the new one, but it forgets to check if ->producer
is beyond the new size at the end of the operation. This leads
to an out-of-bound access in __ptr_ring_produce() as reported
by syzbot.
Reported-by: syzbot+8993c0fa96d57c399735@syzkaller.appspotmail.com
Fixes: 5d49de532002 ("ptr_ring: resize support")
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/ptr_ring.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index 6894976b54e3..186cd8e970c7 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -573,6 +573,8 @@ static inline void **__ptr_ring_swap_queue(struct ptr_ring *r, void **queue, else if (destroy) destroy(ptr); + if (producer >= size) + producer = 0; __ptr_ring_set_size(r, size); r->producer = producer; r->consumer_head = 0; |