From 83cf5c68d663fc78ce529c41bf24f9f6be88bef4 Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Wed, 2 Sep 2020 09:36:04 +0200 Subject: xsk: Fix use-after-free in failed shared_umem bind Fix use-after-free when a shared umem bind fails. The code incorrectly tried to free the allocated buffer pool both in the bind code and then later also when the socket was released. Fix this by setting the buffer pool pointer to NULL after the bind code has freed the pool, so that the socket release code will not try to free the pool. This is the same solution as the regular, non-shared umem code path has. This was missing from the shared umem path. Fixes: b5aea28dca13 ("xsk: Add shared umem support between queue ids") Reported-by: syzbot+5334f62e4d22804e646a@syzkaller.appspotmail.com Signed-off-by: Magnus Karlsson Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/1599032164-25684-1-git-send-email-magnus.karlsson@intel.com --- net/xdp/xsk.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/xdp') diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 07c32276c527..3895697f8540 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -711,6 +711,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len) dev, qid); if (err) { xp_destroy(xs->pool); + xs->pool = NULL; sockfd_put(sock); goto out_unlock; } -- cgit v1.2.3