[PATCH net] net: avoid uninit-value from tcp_conn_request
From: Eric Dumazet <hidden>
Date: 2021-11-30 18:29:45
From: Eric Dumazet <edumazet@google.com>
A recent change triggers a KMSAN warning, because request
sockets do not initialize @sk_rx_queue_mapping field.
Add sk_rx_queue_update() helper to make our intent clear.
BUG: KMSAN: uninit-value in sk_rx_queue_set include/net/sock.h:1922 [inline]
BUG: KMSAN: uninit-value in tcp_conn_request+0x3bcc/0x4dc0 net/ipv4/tcp_input.c:6922
sk_rx_queue_set include/net/sock.h:1922 [inline]
tcp_conn_request+0x3bcc/0x4dc0 net/ipv4/tcp_input.c:6922
tcp_v4_conn_request+0x218/0x2a0 net/ipv4/tcp_ipv4.c:1528
tcp_rcv_state_process+0x2c5/0x3290 net/ipv4/tcp_input.c:6406
tcp_v4_do_rcv+0xb4e/0x1330 net/ipv4/tcp_ipv4.c:1738
tcp_v4_rcv+0x468d/0x4ed0 net/ipv4/tcp_ipv4.c:2100
ip_protocol_deliver_rcu+0x760/0x10b0 net/ipv4/ip_input.c:204
ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
NF_HOOK include/linux/netfilter.h:307 [inline]
ip_local_deliver+0x584/0x8c0 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:460 [inline]
ip_sublist_rcv_finish net/ipv4/ip_input.c:551 [inline]
ip_list_rcv_finish net/ipv4/ip_input.c:601 [inline]
ip_sublist_rcv+0x11fd/0x1520 net/ipv4/ip_input.c:609
ip_list_rcv+0x95f/0x9a0 net/ipv4/ip_input.c:644
__netif_receive_skb_list_ptype net/core/dev.c:5505 [inline]
__netif_receive_skb_list_core+0xe34/0x1240 net/core/dev.c:5553
__netif_receive_skb_list+0x7fc/0x960 net/core/dev.c:5605
netif_receive_skb_list_internal+0x868/0xde0 net/core/dev.c:5696
gro_normal_list net/core/dev.c:5850 [inline]
napi_complete_done+0x579/0xdd0 net/core/dev.c:6587
virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
virtnet_poll+0x17b6/0x2350 drivers/net/virtio_net.c:1557
__napi_poll+0x14e/0xbc0 net/core/dev.c:7020
napi_poll net/core/dev.c:7087 [inline]
net_rx_action+0x824/0x1880 net/core/dev.c:7174
__do_softirq+0x1fe/0x7eb kernel/softirq.c:558
invoke_softirq+0xa4/0x130 kernel/softirq.c:432
__irq_exit_rcu kernel/softirq.c:636 [inline]
irq_exit_rcu+0x76/0x130 kernel/softirq.c:648
common_interrupt+0xb6/0xd0 arch/x86/kernel/irq.c:240
asm_common_interrupt+0x1e/0x40
smap_restore arch/x86/include/asm/smap.h:67 [inline]
get_shadow_origin_ptr mm/kmsan/instrumentation.c:31 [inline]
__msan_metadata_ptr_for_load_1+0x28/0x30 mm/kmsan/instrumentation.c:63
tomoyo_check_acl+0x1b0/0x630 security/tomoyo/domain.c:173
tomoyo_path_permission security/tomoyo/file.c:586 [inline]
tomoyo_check_open_permission+0x61f/0xe10 security/tomoyo/file.c:777
tomoyo_file_open+0x24f/0x2d0 security/tomoyo/tomoyo.c:311
security_file_open+0xb1/0x1f0 security/security.c:1635
do_dentry_open+0x4e4/0x1bf0 fs/open.c:809
vfs_open+0xaf/0xe0 fs/open.c:957
do_open fs/namei.c:3426 [inline]
path_openat+0x52f1/0x5dd0 fs/namei.c:3559
do_filp_open+0x306/0x760 fs/namei.c:3586
do_sys_openat2+0x263/0x8f0 fs/open.c:1212
do_sys_open fs/open.c:1228 [inline]
__do_sys_open fs/open.c:1236 [inline]
__se_sys_open fs/open.c:1232 [inline]
__x64_sys_open+0x314/0x380 fs/open.c:1232
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x44/0xae
Uninit was created at:
__alloc_pages+0xbc7/0x10a0 mm/page_alloc.c:5409
alloc_pages+0x8a5/0xb80
alloc_slab_page mm/slub.c:1810 [inline]
allocate_slab+0x287/0x1c20 mm/slub.c:1947
new_slab mm/slub.c:2010 [inline]
___slab_alloc+0xbdf/0x1e90 mm/slub.c:3039
__slab_alloc mm/slub.c:3126 [inline]
slab_alloc_node mm/slub.c:3217 [inline]
slab_alloc mm/slub.c:3259 [inline]
kmem_cache_alloc+0xbb3/0x11c0 mm/slub.c:3264
reqsk_alloc include/net/request_sock.h:91 [inline]
inet_reqsk_alloc+0xaf/0x8b0 net/ipv4/tcp_input.c:6712
tcp_conn_request+0x910/0x4dc0 net/ipv4/tcp_input.c:6852
tcp_v4_conn_request+0x218/0x2a0 net/ipv4/tcp_ipv4.c:1528
tcp_rcv_state_process+0x2c5/0x3290 net/ipv4/tcp_input.c:6406
tcp_v4_do_rcv+0xb4e/0x1330 net/ipv4/tcp_ipv4.c:1738
tcp_v4_rcv+0x468d/0x4ed0 net/ipv4/tcp_ipv4.c:2100
ip_protocol_deliver_rcu+0x760/0x10b0 net/ipv4/ip_input.c:204
ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
NF_HOOK include/linux/netfilter.h:307 [inline]
ip_local_deliver+0x584/0x8c0 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:460 [inline]
ip_sublist_rcv_finish net/ipv4/ip_input.c:551 [inline]
ip_list_rcv_finish net/ipv4/ip_input.c:601 [inline]
ip_sublist_rcv+0x11fd/0x1520 net/ipv4/ip_input.c:609
ip_list_rcv+0x95f/0x9a0 net/ipv4/ip_input.c:644
__netif_receive_skb_list_ptype net/core/dev.c:5505 [inline]
__netif_receive_skb_list_core+0xe34/0x1240 net/core/dev.c:5553
__netif_receive_skb_list+0x7fc/0x960 net/core/dev.c:5605
netif_receive_skb_list_internal+0x868/0xde0 net/core/dev.c:5696
gro_normal_list net/core/dev.c:5850 [inline]
napi_complete_done+0x579/0xdd0 net/core/dev.c:6587
virtqueue_napi_complete drivers/net/virtio_net.c:339 [inline]
virtnet_poll+0x17b6/0x2350 drivers/net/virtio_net.c:1557
__napi_poll+0x14e/0xbc0 net/core/dev.c:7020
napi_poll net/core/dev.c:7087 [inline]
net_rx_action+0x824/0x1880 net/core/dev.c:7174
__do_softirq+0x1fe/0x7eb kernel/softirq.c:558
Fixes: 342159ee394d ("net: avoid dirtying sk->sk_rx_queue_mapping")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <redacted>
---
include/net/busy_poll.h | 2 +-
include/net/sock.h | 18 ++++++++++++++++--
2 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 4202c609bb0b09345c0f1c5105adf409a3a89f74..7994455ec714610fbcb563d8c7a1411b02201e05 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h@@ -133,7 +133,7 @@ static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb) if (unlikely(READ_ONCE(sk->sk_napi_id) != skb->napi_id)) WRITE_ONCE(sk->sk_napi_id, skb->napi_id); #endif - sk_rx_queue_set(sk, skb); + sk_rx_queue_update(sk, skb); } static inline void __sk_mark_napi_id_once(struct sock *sk, unsigned int napi_id)
diff --git a/include/net/sock.h b/include/net/sock.h
index 715cdb4b2b79c4e79256fe5421c98a70e2eff880..9058634a9709f5d148eea29dd069b16cc5818d04 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h@@ -1913,18 +1913,32 @@ static inline int sk_tx_queue_get(const struct sock *sk) return -1; } -static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb) +static inline void __sk_rx_queue_set(struct sock *sk, + const struct sk_buff *skb, + bool force_set) { #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING if (skb_rx_queue_recorded(skb)) { u16 rx_queue = skb_get_rx_queue(skb); - if (unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue)) + if (force_set || + unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue)) WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue); } #endif } +static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb) +{ + __sk_rx_queue_set(sk, skb, true); +} + +static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb) +{ + __sk_rx_queue_set(sk, skb, false); +} + + static inline void sk_rx_queue_clear(struct sock *sk) { #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
--
2.34.0.rc2.393.gf8c9666880-goog