A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-13 08:07:32 -04:00
Code Issues Projects Releases Packages Wiki Activity

udp: fix race between close() and udp_abort()

Browse source 
Kaustubh reported and diagnosed a panic in udp_lib_lookup().
The root cause is udp_abort() racing with close(). Both
racing functions acquire the socket lock, but udp{v6}_destroy_sock()
release it before performing destructive actions.

We can't easily extend the socket lock scope to avoid the race,
instead use the SOCK_DEAD flag to prevent udp_abort from doing
any action when the critical race happens.

Change-Id: I8ec3f73ed5f8324722b29450c37b4ae23a81c0f3
Diagnosed-and-tested-by: Kaustubh Pandey <kapandey@codeaurora.org>
Fixes: 5d77dca828 ("net: diag: support SOCK_DESTROY for UDP sockets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-Commit: a8b897c7bcd47f4147d066e22cc01d1026d7640e
Git-repo: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git
Signed-off-by: Kaustubh Pandey <kapandey@codeaurora.org>
This commit is contained in:
Paolo Abeni 2021-06-09 11:49:01 +02:00 • committed by Gerrit - the friendly Code Review server
commit a864e70eef
2 changed files with 13 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

10
net/ipv4/udp.c
View file

@ -2510,6 +2510,9 @@ void udp_destroy_sock(struct sock *sk)
{
struct udp_sock *up = udp_sk(sk);
bool slow = lock_sock_fast(sk);
/* protects from races with udp_abort() */
sock_set_flag(sk, SOCK_DEAD);
udp_flush_pending_frames(sk);
unlock_sock_fast(sk, slow);
if (static_branch_unlikely(&udp_encap_needed_key)) {
@ -2765,10 +2768,17 @@ int udp_abort(struct sock *sk, int err)
{
lock_sock(sk);
/* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing
* with close()
*/
if (sock_flag(sk, SOCK_DEAD))
goto out;
sk->sk_err = err;
sk->sk_error_report(sk);
__udp_disconnect(sk, 0);
out:
release_sock(sk);
return 0;

3
net/ipv6/udp.c
View file

@ -1539,6 +1539,9 @@ void udpv6_destroy_sock(struct sock *sk)
{
struct udp_sock *up = udp_sk(sk);
lock_sock(sk);
/* protects from races with udp_abort() */
sock_set_flag(sk, SOCK_DEAD);
udp_v6_flush_pending_frames(sk);
release_sock(sk);