FROMLIST: net/packet: fix overflow in check for tp_frame_nr When calculating rb->frames_per_block * req->tp_block_nr the result can overflow. Add a check that tp_block_size * tp_block_nr <= UINT_MAX. Since frames_per_block <= tp_block_size, the expression would never overflow. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Eric Dumazet <edumazet@google.com> (am from https://patchwork.ozlabs.org/patch/744813/) BUG=b:36725429 TEST=kernel compiles Change-Id: Ibbd6c5ae89957d11a52a673e56ad6f09025de708 Reviewed-on: https://chromium-review.googlesource.com/462400 Reviewed-by: Guenter Roeck <groeck@chromium.org> Commit-Queue: Andrey Ulanov <andreyu@google.com> Tested-by: Andrey Ulanov <andreyu@google.com>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index b0dd512..c859f55c 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c
@@ -4148,6 +4148,8 @@ rb->frames_per_block = req->tp_block_size / req->tp_frame_size; if (unlikely(rb->frames_per_block == 0)) goto out; + if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr)) + goto out; if (unlikely((rb->frames_per_block * req->tp_block_nr) != req->tp_frame_nr)) goto out;
