--- /dev/null
+From 8f905c0e7354ef261360fb7535ea079b1082c105 Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Mon, 20 Dec 2021 06:33:30 -0800
+Subject: inet: fully convert sk->sk_rx_dst to RCU rules
+
+From: Eric Dumazet <edumazet@google.com>
+
+commit 8f905c0e7354ef261360fb7535ea079b1082c105 upstream.
+
+syzbot reported various issues around early demux,
+one being included in this changelog [1]
+
+sk->sk_rx_dst is using RCU protection without clearly
+documenting it.
+
+And following sequences in tcp_v4_do_rcv()/tcp_v6_do_rcv()
+are not following standard RCU rules.
+
+[a] dst_release(dst);
+[b] sk->sk_rx_dst = NULL;
+
+They look wrong because a delete operation of RCU protected
+pointer is supposed to clear the pointer before
+the call_rcu()/synchronize_rcu() guarding actual memory freeing.
+
+In some cases indeed, dst could be freed before [b] is done.
+
+We could cheat by clearing sk_rx_dst before calling
+dst_release(), but this seems the right time to stick
+to standard RCU annotations and debugging facilities.
+
+[1]
+BUG: KASAN: use-after-free in dst_check include/net/dst.h:470 [inline]
+BUG: KASAN: use-after-free in tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792
+Read of size 2 at addr ffff88807f1cb73a by task syz-executor.5/9204
+
+CPU: 0 PID: 9204 Comm: syz-executor.5 Not tainted 5.16.0-rc5-syzkaller #0
+Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
+Call Trace:
+ <TASK>
+ __dump_stack lib/dump_stack.c:88 [inline]
+ dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
+ print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247
+ __kasan_report mm/kasan/report.c:433 [inline]
+ kasan_report.cold+0x83/0xdf mm/kasan/report.c:450
+ dst_check include/net/dst.h:470 [inline]
+ tcp_v4_early_demux+0x95b/0x960 net/ipv4/tcp_ipv4.c:1792
+ ip_rcv_finish_core.constprop.0+0x15de/0x1e80 net/ipv4/ip_input.c:340
+ ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583
+ ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]
+ ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644
+ __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]
+ __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556
+ __netif_receive_skb_list net/core/dev.c:5608 [inline]
+ netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699
+ gro_normal_list net/core/dev.c:5853 [inline]
+ gro_normal_list net/core/dev.c:5849 [inline]
+ napi_complete_done+0x1f1/0x880 net/core/dev.c:6590
+ virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
+ virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557
+ __napi_poll+0xaf/0x440 net/core/dev.c:7023
+ napi_poll net/core/dev.c:7090 [inline]
+ net_rx_action+0x801/0xb40 net/core/dev.c:7177
+ __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
+ invoke_softirq kernel/softirq.c:432 [inline]
+ __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
+ irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
+ common_interrupt+0x52/0xc0 arch/x86/kernel/irq.c:240
+ asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629
+RIP: 0033:0x7f5e972bfd57
+Code: 39 d1 73 14 0f 1f 80 00 00 00 00 48 8b 50 f8 48 83 e8 08 48 39 ca 77 f3 48 39 c3 73 3e 48 89 13 48 8b 50 f8 48 89 38 49 8b 0e <48> 8b 3e 48 83 c3 08 48 83 c6 08 eb bc 48 39 d1 72 9e 48 39 d0 73
+RSP: 002b:00007fff8a413210 EFLAGS: 00000283
+RAX: 00007f5e97108990 RBX: 00007f5e97108338 RCX: ffffffff81d3aa45
+RDX: ffffffff81d3aa45 RSI: 00007f5e97108340 RDI: ffffffff81d3aa45
+RBP: 00007f5e97107eb8 R08: 00007f5e97108d88 R09: 0000000093c2e8d9
+R10: 0000000000000000 R11: 0000000000000000 R12: 00007f5e97107eb0
+R13: 00007f5e97108338 R14: 00007f5e97107ea8 R15: 0000000000000019
+ </TASK>
+
+Allocated by task 13:
+ kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
+ kasan_set_track mm/kasan/common.c:46 [inline]
+ set_alloc_info mm/kasan/common.c:434 [inline]
+ __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:467
+ kasan_slab_alloc include/linux/kasan.h:259 [inline]
+ slab_post_alloc_hook mm/slab.h:519 [inline]
+ slab_alloc_node mm/slub.c:3234 [inline]
+ slab_alloc mm/slub.c:3242 [inline]
+ kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3247
+ dst_alloc+0x146/0x1f0 net/core/dst.c:92
+ rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613
+ ip_route_input_slow+0x1817/0x3a20 net/ipv4/route.c:2340
+ ip_route_input_rcu net/ipv4/route.c:2470 [inline]
+ ip_route_input_noref+0x116/0x2a0 net/ipv4/route.c:2415
+ ip_rcv_finish_core.constprop.0+0x288/0x1e80 net/ipv4/ip_input.c:354
+ ip_list_rcv_finish.constprop.0+0x1b2/0x6e0 net/ipv4/ip_input.c:583
+ ip_sublist_rcv net/ipv4/ip_input.c:609 [inline]
+ ip_list_rcv+0x34e/0x490 net/ipv4/ip_input.c:644
+ __netif_receive_skb_list_ptype net/core/dev.c:5508 [inline]
+ __netif_receive_skb_list_core+0x549/0x8e0 net/core/dev.c:5556
+ __netif_receive_skb_list net/core/dev.c:5608 [inline]
+ netif_receive_skb_list_internal+0x75e/0xd80 net/core/dev.c:5699
+ gro_normal_list net/core/dev.c:5853 [inline]
+ gro_normal_list net/core/dev.c:5849 [inline]
+ napi_complete_done+0x1f1/0x880 net/core/dev.c:6590
+ virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
+ virtnet_poll+0xca2/0x11b0 drivers/net/virtio_net.c:1557
+ __napi_poll+0xaf/0x440 net/core/dev.c:7023
+ napi_poll net/core/dev.c:7090 [inline]
+ net_rx_action+0x801/0xb40 net/core/dev.c:7177
+ __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
+
+Freed by task 13:
+ kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
+ kasan_set_track+0x21/0x30 mm/kasan/common.c:46
+ kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
+ ____kasan_slab_free mm/kasan/common.c:366 [inline]
+ ____kasan_slab_free mm/kasan/common.c:328 [inline]
+ __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
+ kasan_slab_free include/linux/kasan.h:235 [inline]
+ slab_free_hook mm/slub.c:1723 [inline]
+ slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749
+ slab_free mm/slub.c:3513 [inline]
+ kmem_cache_free+0xbd/0x5d0 mm/slub.c:3530
+ dst_destroy+0x2d6/0x3f0 net/core/dst.c:127
+ rcu_do_batch kernel/rcu/tree.c:2506 [inline]
+ rcu_core+0x7ab/0x1470 kernel/rcu/tree.c:2741
+ __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
+
+Last potentially related work creation:
+ kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
+ __kasan_record_aux_stack+0xf5/0x120 mm/kasan/generic.c:348
+ __call_rcu kernel/rcu/tree.c:2985 [inline]
+ call_rcu+0xb1/0x740 kernel/rcu/tree.c:3065
+ dst_release net/core/dst.c:177 [inline]
+ dst_release+0x79/0xe0 net/core/dst.c:167
+ tcp_v4_do_rcv+0x612/0x8d0 net/ipv4/tcp_ipv4.c:1712
+ sk_backlog_rcv include/net/sock.h:1030 [inline]
+ __release_sock+0x134/0x3b0 net/core/sock.c:2768
+ release_sock+0x54/0x1b0 net/core/sock.c:3300
+ tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1441
+ inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819
+ sock_sendmsg_nosec net/socket.c:704 [inline]
+ sock_sendmsg+0xcf/0x120 net/socket.c:724
+ sock_write_iter+0x289/0x3c0 net/socket.c:1057
+ call_write_iter include/linux/fs.h:2162 [inline]
+ new_sync_write+0x429/0x660 fs/read_write.c:503
+ vfs_write+0x7cd/0xae0 fs/read_write.c:590
+ ksys_write+0x1ee/0x250 fs/read_write.c:643
+ do_syscall_x64 arch/x86/entry/common.c:50 [inline]
+ do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
+ entry_SYSCALL_64_after_hwframe+0x44/0xae
+
+The buggy address belongs to the object at ffff88807f1cb700
+ which belongs to the cache ip_dst_cache of size 176
+The buggy address is located 58 bytes inside of
+ 176-byte region [ffff88807f1cb700, ffff88807f1cb7b0)
+The buggy address belongs to the page:
+page:ffffea0001fc72c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7f1cb
+flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
+raw: 00fff00000000200 dead000000000100 dead000000000122 ffff8881413bb780
+raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
+page dumped because: kasan: bad access detected
+page_owner tracks the page as allocated
+page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5, ts 108466983062, free_ts 108048976062
+ prep_new_page mm/page_alloc.c:2418 [inline]
+ get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4149
+ __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5369
+ alloc_pages+0x1a7/0x300 mm/mempolicy.c:2191
+ alloc_slab_page mm/slub.c:1793 [inline]
+ allocate_slab mm/slub.c:1930 [inline]
+ new_slab+0x32d/0x4a0 mm/slub.c:1993
+ ___slab_alloc+0x918/0xfe0 mm/slub.c:3022
+ __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3109
+ slab_alloc_node mm/slub.c:3200 [inline]
+ slab_alloc mm/slub.c:3242 [inline]
+ kmem_cache_alloc+0x35c/0x3a0 mm/slub.c:3247
+ dst_alloc+0x146/0x1f0 net/core/dst.c:92
+ rt_dst_alloc+0x73/0x430 net/ipv4/route.c:1613
+ __mkroute_output net/ipv4/route.c:2564 [inline]
+ ip_route_output_key_hash_rcu+0x921/0x2d00 net/ipv4/route.c:2791
+ ip_route_output_key_hash+0x18b/0x300 net/ipv4/route.c:2619
+ __ip_route_output_key include/net/route.h:126 [inline]
+ ip_route_output_flow+0x23/0x150 net/ipv4/route.c:2850
+ ip_route_output_key include/net/route.h:142 [inline]
+ geneve_get_v4_rt+0x3a6/0x830 drivers/net/geneve.c:809
+ geneve_xmit_skb drivers/net/geneve.c:899 [inline]
+ geneve_xmit+0xc4a/0x3540 drivers/net/geneve.c:1082
+ __netdev_start_xmit include/linux/netdevice.h:4994 [inline]
+ netdev_start_xmit include/linux/netdevice.h:5008 [inline]
+ xmit_one net/core/dev.c:3590 [inline]
+ dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3606
+ __dev_queue_xmit+0x299a/0x3650 net/core/dev.c:4229
+page last free stack trace:
+ reset_page_owner include/linux/page_owner.h:24 [inline]
+ free_pages_prepare mm/page_alloc.c:1338 [inline]
+ free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1389
+ free_unref_page_prepare mm/page_alloc.c:3309 [inline]
+ free_unref_page+0x19/0x690 mm/page_alloc.c:3388
+ qlink_free mm/kasan/quarantine.c:146 [inline]
+ qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165
+ kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
+ __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:444
+ kasan_slab_alloc include/linux/kasan.h:259 [inline]
+ slab_post_alloc_hook mm/slab.h:519 [inline]
+ slab_alloc_node mm/slub.c:3234 [inline]
+ kmem_cache_alloc_node+0x255/0x3f0 mm/slub.c:3270
+ __alloc_skb+0x215/0x340 net/core/skbuff.c:414
+ alloc_skb include/linux/skbuff.h:1126 [inline]
+ alloc_skb_with_frags+0x93/0x620 net/core/skbuff.c:6078
+ sock_alloc_send_pskb+0x783/0x910 net/core/sock.c:2575
+ mld_newpack+0x1df/0x770 net/ipv6/mcast.c:1754
+ add_grhead+0x265/0x330 net/ipv6/mcast.c:1857
+ add_grec+0x1053/0x14e0 net/ipv6/mcast.c:1995
+ mld_send_initial_cr.part.0+0xf6/0x230 net/ipv6/mcast.c:2242
+ mld_send_initial_cr net/ipv6/mcast.c:1232 [inline]
+ mld_dad_work+0x1d3/0x690 net/ipv6/mcast.c:2268
+ process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
+ worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
+
+Memory state around the buggy address:
+ ffff88807f1cb600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+ ffff88807f1cb680: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
+>ffff88807f1cb700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+ ^
+ ffff88807f1cb780: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
+ ffff88807f1cb800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
+
+Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.")
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Link: https://lore.kernel.org/r/20211220143330.680945-1-eric.dumazet@gmail.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+[cmllamas: fixed trivial merge conflict]
+Signed-off-by: Carlos Llamas <cmllamas@google.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/net/sock.h | 2 +-
+ net/ipv4/af_inet.c | 2 +-
+ net/ipv4/tcp.c | 3 +--
+ net/ipv4/tcp_input.c | 2 +-
+ net/ipv4/tcp_ipv4.c | 11 +++++++----
+ net/ipv4/udp.c | 6 +++---
+ net/ipv6/tcp_ipv6.c | 11 +++++++----
+ net/ipv6/udp.c | 4 ++--
+ 8 files changed, 23 insertions(+), 18 deletions(-)
+
+--- a/include/net/sock.h
++++ b/include/net/sock.h
+@@ -421,7 +421,7 @@ struct sock {
+ #ifdef CONFIG_XFRM
+ struct xfrm_policy __rcu *sk_policy[2];
+ #endif
+- struct dst_entry *sk_rx_dst;
++ struct dst_entry __rcu *sk_rx_dst;
+ struct dst_entry __rcu *sk_dst_cache;
+ atomic_t sk_omem_alloc;
+ int sk_sndbuf;
+--- a/net/ipv4/af_inet.c
++++ b/net/ipv4/af_inet.c
+@@ -158,7 +158,7 @@ void inet_sock_destruct(struct sock *sk)
+
+ kfree(rcu_dereference_protected(inet->inet_opt, 1));
+ dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
+- dst_release(sk->sk_rx_dst);
++ dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
+ sk_refcnt_debug_dec(sk);
+ }
+ EXPORT_SYMBOL(inet_sock_destruct);
+--- a/net/ipv4/tcp.c
++++ b/net/ipv4/tcp.c
+@@ -2816,8 +2816,7 @@ int tcp_disconnect(struct sock *sk, int
+ icsk->icsk_ack.rcv_mss = TCP_MIN_MSS;
+ memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
+ __sk_dst_reset(sk);
+- dst_release(sk->sk_rx_dst);
+- sk->sk_rx_dst = NULL;
++ dst_release(xchg((__force struct dst_entry **)&sk->sk_rx_dst, NULL));
+ tcp_saved_syn_free(tp);
+ tp->compressed_ack = 0;
+ tp->segs_in = 0;
+--- a/net/ipv4/tcp_input.c
++++ b/net/ipv4/tcp_input.c
+@@ -5777,7 +5777,7 @@ void tcp_rcv_established(struct sock *sk
+ trace_tcp_probe(sk, skb);
+
+ tcp_mstamp_refresh(tp);
+- if (unlikely(!sk->sk_rx_dst))
++ if (unlikely(!rcu_access_pointer(sk->sk_rx_dst)))
+ inet_csk(sk)->icsk_af_ops->sk_rx_dst_set(sk, skb);
+ /*
+ * Header prediction.
+--- a/net/ipv4/tcp_ipv4.c
++++ b/net/ipv4/tcp_ipv4.c
+@@ -1670,15 +1670,18 @@ int tcp_v4_do_rcv(struct sock *sk, struc
+ struct sock *rsk;
+
+ if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
+- struct dst_entry *dst = sk->sk_rx_dst;
++ struct dst_entry *dst;
++
++ dst = rcu_dereference_protected(sk->sk_rx_dst,
++ lockdep_sock_is_held(sk));
+
+ sock_rps_save_rxhash(sk, skb);
+ sk_mark_napi_id(sk, skb);
+ if (dst) {
+ if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
+ !dst->ops->check(dst, 0)) {
++ RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
+ dst_release(dst);
+- sk->sk_rx_dst = NULL;
+ }
+ }
+ tcp_rcv_established(sk, skb);
+@@ -1753,7 +1756,7 @@ int tcp_v4_early_demux(struct sk_buff *s
+ skb->sk = sk;
+ skb->destructor = sock_edemux;
+ if (sk_fullsock(sk)) {
+- struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
++ struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
+
+ if (dst)
+ dst = dst_check(dst, 0);
+@@ -2162,7 +2165,7 @@ void inet_sk_rx_dst_set(struct sock *sk,
+ struct dst_entry *dst = skb_dst(skb);
+
+ if (dst && dst_hold_safe(dst)) {
+- sk->sk_rx_dst = dst;
++ rcu_assign_pointer(sk->sk_rx_dst, dst);
+ inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
+ }
+ }
+--- a/net/ipv4/udp.c
++++ b/net/ipv4/udp.c
+@@ -2193,7 +2193,7 @@ bool udp_sk_rx_dst_set(struct sock *sk,
+ struct dst_entry *old;
+
+ if (dst_hold_safe(dst)) {
+- old = xchg(&sk->sk_rx_dst, dst);
++ old = xchg((__force struct dst_entry **)&sk->sk_rx_dst, dst);
+ dst_release(old);
+ return old != dst;
+ }
+@@ -2383,7 +2383,7 @@ int __udp4_lib_rcv(struct sk_buff *skb,
+ struct dst_entry *dst = skb_dst(skb);
+ int ret;
+
+- if (unlikely(sk->sk_rx_dst != dst))
++ if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
+ udp_sk_rx_dst_set(sk, dst);
+
+ ret = udp_unicast_rcv_skb(sk, skb, uh);
+@@ -2541,7 +2541,7 @@ int udp_v4_early_demux(struct sk_buff *s
+
+ skb->sk = sk;
+ skb->destructor = sock_efree;
+- dst = READ_ONCE(sk->sk_rx_dst);
++ dst = rcu_dereference(sk->sk_rx_dst);
+
+ if (dst)
+ dst = dst_check(dst, 0);
+--- a/net/ipv6/tcp_ipv6.c
++++ b/net/ipv6/tcp_ipv6.c
+@@ -107,7 +107,7 @@ static void inet6_sk_rx_dst_set(struct s
+ if (dst && dst_hold_safe(dst)) {
+ const struct rt6_info *rt = (const struct rt6_info *)dst;
+
+- sk->sk_rx_dst = dst;
++ rcu_assign_pointer(sk->sk_rx_dst, dst);
+ inet_sk(sk)->rx_dst_ifindex = skb->skb_iif;
+ tcp_inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt);
+ }
+@@ -1482,15 +1482,18 @@ static int tcp_v6_do_rcv(struct sock *sk
+ opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
+
+ if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
+- struct dst_entry *dst = sk->sk_rx_dst;
++ struct dst_entry *dst;
++
++ dst = rcu_dereference_protected(sk->sk_rx_dst,
++ lockdep_sock_is_held(sk));
+
+ sock_rps_save_rxhash(sk, skb);
+ sk_mark_napi_id(sk, skb);
+ if (dst) {
+ if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif ||
+ dst->ops->check(dst, np->rx_dst_cookie) == NULL) {
++ RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
+ dst_release(dst);
+- sk->sk_rx_dst = NULL;
+ }
+ }
+
+@@ -1842,7 +1845,7 @@ INDIRECT_CALLABLE_SCOPE void tcp_v6_earl
+ skb->sk = sk;
+ skb->destructor = sock_edemux;
+ if (sk_fullsock(sk)) {
+- struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst);
++ struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
+
+ if (dst)
+ dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie);
+--- a/net/ipv6/udp.c
++++ b/net/ipv6/udp.c
+@@ -941,7 +941,7 @@ int __udp6_lib_rcv(struct sk_buff *skb,
+ struct dst_entry *dst = skb_dst(skb);
+ int ret;
+
+- if (unlikely(sk->sk_rx_dst != dst))
++ if (unlikely(rcu_dereference(sk->sk_rx_dst) != dst))
+ udp6_sk_rx_dst_set(sk, dst);
+
+ if (!uh->check && !udp_sk(sk)->no_check6_rx) {
+@@ -1055,7 +1055,7 @@ INDIRECT_CALLABLE_SCOPE void udp_v6_earl
+
+ skb->sk = sk;
+ skb->destructor = sock_efree;
+- dst = READ_ONCE(sk->sk_rx_dst);
++ dst = rcu_dereference(sk->sk_rx_dst);
+
+ if (dst)
+ dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);
projects / thirdparty / kernel / stable-queue.git / commitdiff
