diff options
author | Eric Dumazet <edumazet@google.com> | 2017-12-05 12:45:56 -0800 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-12-05 18:06:09 -0500 |
commit | d7efc6c11b277d9d80b99b1334a78bfe7d7edf10 (patch) | |
tree | 3bb82465c1d56f20b738ee22aeaf883090d0a709 | |
parent | a5266440d5c7872895e964a36822104f6038d142 (diff) | |
download | linux-d7efc6c11b277d9d80b99b1334a78bfe7d7edf10.tar.bz2 |
net: remove hlist_nulls_add_tail_rcu()
Alexander Potapenko reported use of uninitialized memory [1]
This happens when inserting a request socket into TCP ehash,
in __sk_nulls_add_node_rcu(), since sk_reuseport is not initialized.
Bug was added by commit d894ba18d4e4 ("soreuseport: fix ordering for
mixed v4/v6 sockets")
Note that d296ba60d8e2 ("soreuseport: Resolve merge conflict for v4/v6
ordering fix") missed the opportunity to get rid of
hlist_nulls_add_tail_rcu() :
Both UDP sockets and TCP/DCCP listeners no longer use
__sk_nulls_add_node_rcu() for their hash insertion.
Since all other sockets have unique 4-tuple, the reuseport status
has no special meaning, so we can always use hlist_nulls_add_head_rcu()
for them and save few cycles/instructions.
[1]
==================================================================
BUG: KMSAN: use of uninitialized memory in inet_ehash_insert+0xd40/0x1050
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.13.0+ #3288
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:16
dump_stack+0x185/0x1d0 lib/dump_stack.c:52
kmsan_report+0x13f/0x1c0 mm/kmsan/kmsan.c:1016
__msan_warning_32+0x69/0xb0 mm/kmsan/kmsan_instr.c:766
__sk_nulls_add_node_rcu ./include/net/sock.h:684
inet_ehash_insert+0xd40/0x1050 net/ipv4/inet_hashtables.c:413
reqsk_queue_hash_req net/ipv4/inet_connection_sock.c:754
inet_csk_reqsk_queue_hash_add+0x1cc/0x300 net/ipv4/inet_connection_sock.c:765
tcp_conn_request+0x31e7/0x36f0 net/ipv4/tcp_input.c:6414
tcp_v4_conn_request+0x16d/0x220 net/ipv4/tcp_ipv4.c:1314
tcp_rcv_state_process+0x42a/0x7210 net/ipv4/tcp_input.c:5917
tcp_v4_do_rcv+0xa6a/0xcd0 net/ipv4/tcp_ipv4.c:1483
tcp_v4_rcv+0x3de0/0x4ab0 net/ipv4/tcp_ipv4.c:1763
ip_local_deliver_finish+0x6bb/0xcb0 net/ipv4/ip_input.c:216
NF_HOOK ./include/linux/netfilter.h:248
ip_local_deliver+0x3fa/0x480 net/ipv4/ip_input.c:257
dst_input ./include/net/dst.h:477
ip_rcv_finish+0x6fb/0x1540 net/ipv4/ip_input.c:397
NF_HOOK ./include/linux/netfilter.h:248
ip_rcv+0x10f6/0x15c0 net/ipv4/ip_input.c:488
__netif_receive_skb_core+0x36f6/0x3f60 net/core/dev.c:4298
__netif_receive_skb net/core/dev.c:4336
netif_receive_skb_internal+0x63c/0x19c0 net/core/dev.c:4497
napi_skb_finish net/core/dev.c:4858
napi_gro_receive+0x629/0xa50 net/core/dev.c:4889
e1000_receive_skb drivers/net/ethernet/intel/e1000/e1000_main.c:4018
e1000_clean_rx_irq+0x1492/0x1d30
drivers/net/ethernet/intel/e1000/e1000_main.c:4474
e1000_clean+0x43aa/0x5970 drivers/net/ethernet/intel/e1000/e1000_main.c:3819
napi_poll net/core/dev.c:5500
net_rx_action+0x73c/0x1820 net/core/dev.c:5566
__do_softirq+0x4b4/0x8dd kernel/softirq.c:284
invoke_softirq kernel/softirq.c:364
irq_exit+0x203/0x240 kernel/softirq.c:405
exiting_irq+0xe/0x10 ./arch/x86/include/asm/apic.h:638
do_IRQ+0x15e/0x1a0 arch/x86/kernel/irq.c:263
common_interrupt+0x86/0x86
Fixes: d894ba18d4e4 ("soreuseport: fix ordering for mixed v4/v6 sockets")
Fixes: d296ba60d8e2 ("soreuseport: Resolve merge conflict for v4/v6 ordering fix")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Alexander Potapenko <glider@google.com>
Acked-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | include/linux/rculist_nulls.h | 38 | ||||
-rw-r--r-- | include/net/sock.h | 6 |
2 files changed, 1 insertions, 43 deletions
diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h index a328e8181e49..e4b257ff881b 100644 --- a/include/linux/rculist_nulls.h +++ b/include/linux/rculist_nulls.h @@ -101,44 +101,6 @@ static inline void hlist_nulls_add_head_rcu(struct hlist_nulls_node *n, } /** - * hlist_nulls_add_tail_rcu - * @n: the element to add to the hash list. - * @h: the list to add to. - * - * Description: - * Adds the specified element to the end of the specified hlist_nulls, - * while permitting racing traversals. NOTE: tail insertion requires - * list traversal. - * - * The caller must take whatever precautions are necessary - * (such as holding appropriate locks) to avoid racing - * with another list-mutation primitive, such as hlist_nulls_add_head_rcu() - * or hlist_nulls_del_rcu(), running on this same list. - * However, it is perfectly legal to run concurrently with - * the _rcu list-traversal primitives, such as - * hlist_nulls_for_each_entry_rcu(), used to prevent memory-consistency - * problems on Alpha CPUs. Regardless of the type of CPU, the - * list-traversal primitive must be guarded by rcu_read_lock(). - */ -static inline void hlist_nulls_add_tail_rcu(struct hlist_nulls_node *n, - struct hlist_nulls_head *h) -{ - struct hlist_nulls_node *i, *last = NULL; - - for (i = hlist_nulls_first_rcu(h); !is_a_nulls(i); - i = hlist_nulls_next_rcu(i)) - last = i; - - if (last) { - n->next = last->next; - n->pprev = &last->next; - rcu_assign_pointer(hlist_nulls_next_rcu(last), n); - } else { - hlist_nulls_add_head_rcu(n, h); - } -} - -/** * hlist_nulls_for_each_entry_rcu - iterate over rcu list of given type * @tpos: the type * to use as a loop cursor. * @pos: the &struct hlist_nulls_node to use as a loop cursor. diff --git a/include/net/sock.h b/include/net/sock.h index 79e1a2c7912c..9155da422692 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -685,11 +685,7 @@ static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) { - if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport && - sk->sk_family == AF_INET6) - hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list); - else - hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); + hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list); } static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list) |