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authorMagnus Karlsson2020-09-02 10:52:23 +0200
committerDaniel Borkmann2020-09-02 16:49:40 +0200
commit53ea2076d851ee37e4f3954c5ae569439b138248 (patch)
tree42d52f57c17258c1c57da9ff5ff8081c2975fb99
parent858e8b2eb4dd6fe6c4640463ad2f2ed3b8249ad4 (diff)
xsk: Fix possible segfault in xsk umem diagnostics
Fix possible segfault in the xsk diagnostics code when dumping information about the umem. This can happen when a umem has been created, but the socket has not been bound yet. In this case, the xsk buffer pool does not exist yet and we cannot dump the information that was moved from the umem to the buffer pool. Fix this by testing for the existence of the buffer pool and if not there, do not dump any of that information. Fixes: c2d3d6a47462 ("xsk: Move queue_id, dev and need_wakeup to buffer pool") Fixes: 7361f9c3d719 ("xsk: Move fill and completion rings to buffer pool") Reported-by: syzbot+3f04d36b7336f7868066@syzkaller.appspotmail.com Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/1599036743-26454-1-git-send-email-magnus.karlsson@intel.com
-rw-r--r--net/xdp/xsk_diag.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/net/xdp/xsk_diag.c b/net/xdp/xsk_diag.c
index 5bd8ea9d206a..c014217f5fa7 100644
--- a/net/xdp/xsk_diag.c
+++ b/net/xdp/xsk_diag.c
@@ -59,22 +59,20 @@ static int xsk_diag_put_umem(const struct xdp_sock *xs, struct sk_buff *nlskb)
du.num_pages = umem->npgs;
du.chunk_size = umem->chunk_size;
du.headroom = umem->headroom;
- du.ifindex = pool->netdev ? pool->netdev->ifindex : 0;
- du.queue_id = pool->queue_id;
+ du.ifindex = (pool && pool->netdev) ? pool->netdev->ifindex : 0;
+ du.queue_id = pool ? pool->queue_id : 0;
du.flags = 0;
if (umem->zc)
du.flags |= XDP_DU_F_ZEROCOPY;
du.refs = refcount_read(&umem->users);
err = nla_put(nlskb, XDP_DIAG_UMEM, sizeof(du), &du);
-
- if (!err && pool->fq)
+ if (!err && pool && pool->fq)
err = xsk_diag_put_ring(pool->fq,
XDP_DIAG_UMEM_FILL_RING, nlskb);
- if (!err && pool->cq) {
- err = xsk_diag_put_ring(pool->cq, XDP_DIAG_UMEM_COMPLETION_RING,
- nlskb);
- }
+ if (!err && pool && pool->cq)
+ err = xsk_diag_put_ring(pool->cq,
+ XDP_DIAG_UMEM_COMPLETION_RING, nlskb);
return err;
}