| Message ID | 20170717103558.35448-1-glider@google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Mon, Jul 17, 2017 at 12:35 PM, Alexander Potapenko <glider@google.com> wrote: > KMSAN reported use of uninitialized memory in skb_set_hash_from_sk(), > which originated from the TCP request socket created in > cookie_v6_check(): > > ================================================================== > BUG: KMSAN: use of uninitialized memory in tcp_transmit_skb+0xf77/0x3ec0 > CPU: 1 PID: 2949 Comm: syz-execprog Not tainted 4.11.0-rc5+ #2931 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > TCP: request_sock_TCPv6: Possible SYN flooding on port 20028. Sending cookies. Check SNMP counters. > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:16 > dump_stack+0x172/0x1c0 lib/dump_stack.c:52 > kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:927 > __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:469 > skb_set_hash_from_sk ./include/net/sock.h:2011 > tcp_transmit_skb+0xf77/0x3ec0 net/ipv4/tcp_output.c:983 > tcp_send_ack+0x75b/0x830 net/ipv4/tcp_output.c:3493 > tcp_delack_timer_handler+0x9a6/0xb90 net/ipv4/tcp_timer.c:284 > tcp_delack_timer+0x1b0/0x310 net/ipv4/tcp_timer.c:309 > call_timer_fn+0x240/0x520 kernel/time/timer.c:1268 > expire_timers kernel/time/timer.c:1307 > __run_timers+0xc13/0xf10 kernel/time/timer.c:1601 > run_timer_softirq+0x36/0xa0 kernel/time/timer.c:1614 > __do_softirq+0x485/0x942 kernel/softirq.c:284 > invoke_softirq kernel/softirq.c:364 > irq_exit+0x1fa/0x230 kernel/softirq.c:405 > exiting_irq+0xe/0x10 ./arch/x86/include/asm/apic.h:657 > smp_apic_timer_interrupt+0x5a/0x80 arch/x86/kernel/apic/apic.c:966 > apic_timer_interrupt+0x86/0x90 arch/x86/entry/entry_64.S:489 > RIP: 0010:native_restore_fl ./arch/x86/include/asm/irqflags.h:36 > RIP: 0010:arch_local_irq_restore ./arch/x86/include/asm/irqflags.h:77 > RIP: 0010:__msan_poison_alloca+0xed/0x120 mm/kmsan/kmsan_instr.c:440 > RSP: 0018:ffff880024917cd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 > RAX: 0000000000000246 RBX: ffff8800224c0000 RCX: 0000000000000005 > RDX: 0000000000000004 RSI: ffff880000000000 RDI: ffffea0000b6d770 > RBP: ffff880024917d58 R08: 0000000000000dd8 R09: 0000000000000004 > R10: 0000160000000000 R11: 0000000000000000 R12: ffffffff85abf810 > R13: ffff880024917dd8 R14: 0000000000000010 R15: ffffffff81cabde4 > </IRQ> > poll_select_copy_remaining+0xac/0x6b0 fs/select.c:293 > SYSC_select+0x4b4/0x4e0 fs/select.c:653 > SyS_select+0x76/0xa0 fs/select.c:634 > entry_SYSCALL_64_fastpath+0x13/0x94 arch/x86/entry/entry_64.S:204 > RIP: 0033:0x4597e7 > RSP: 002b:000000c420037ee0 EFLAGS: 00000246 ORIG_RAX: 0000000000000017 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004597e7 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: 000000c420037ef0 R08: 000000c420037ee0 R09: 0000000000000059 > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000042dc20 > R13: 00000000000000f3 R14: 0000000000000030 R15: 0000000000000003 > chained origin: > save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59 > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 > kmsan_save_stack mm/kmsan/kmsan.c:317 > kmsan_internal_chain_origin+0x12a/0x1f0 mm/kmsan/kmsan.c:547 > __msan_store_shadow_origin_4+0xac/0x110 mm/kmsan/kmsan_instr.c:259 > tcp_create_openreq_child+0x709/0x1ae0 net/ipv4/tcp_minisocks.c:472 > tcp_v6_syn_recv_sock+0x7eb/0x2a30 net/ipv6/tcp_ipv6.c:1103 > tcp_get_cookie_sock+0x136/0x5f0 net/ipv4/syncookies.c:212 > cookie_v6_check+0x17a9/0x1b50 net/ipv6/syncookies.c:245 > tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989 > tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298 > tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487 > ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279 > NF_HOOK ./include/linux/netfilter.h:257 > ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322 > dst_input ./include/net/dst.h:492 > ip6_rcv_finish net/ipv6/ip6_input.c:69 > NF_HOOK ./include/linux/netfilter.h:257 > ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203 > __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208 > __netif_receive_skb net/core/dev.c:4246 > process_backlog+0x667/0xba0 net/core/dev.c:4866 > napi_poll net/core/dev.c:5268 > net_rx_action+0xc95/0x1590 net/core/dev.c:5333 > __do_softirq+0x485/0x942 kernel/softirq.c:284 > origin: > save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59 > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 > kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:198 > kmsan_kmalloc+0x7f/0xe0 mm/kmsan/kmsan.c:337 > kmem_cache_alloc+0x1c2/0x1e0 mm/slub.c:2766 > reqsk_alloc ./include/net/request_sock.h:87 > inet_reqsk_alloc+0xa4/0x5b0 net/ipv4/tcp_input.c:6200 > cookie_v6_check+0x4f4/0x1b50 net/ipv6/syncookies.c:169 > tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989 > tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298 > tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487 > ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279 > NF_HOOK ./include/linux/netfilter.h:257 > ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322 > dst_input ./include/net/dst.h:492 > ip6_rcv_finish net/ipv6/ip6_input.c:69 > NF_HOOK ./include/linux/netfilter.h:257 > ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203 > __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208 > __netif_receive_skb net/core/dev.c:4246 > process_backlog+0x667/0xba0 net/core/dev.c:4866 > napi_poll net/core/dev.c:5268 > net_rx_action+0xc95/0x1590 net/core/dev.c:5333 > __do_softirq+0x485/0x942 kernel/softirq.c:284 > ================================================================== > > Similar error is reported for cookie_v4_check(). > > Signed-off-by: Alexander Potapenko <glider@google.com> > Fixes: 58d607d3e52f ("tcp: provide skb->hash to synack packets") > --- What I forgot here is the patch changelog. Per request from Eric Dumazet we initialize treq->txhash with the result of net_tx_rndhash(). Per request from Neal Cardwell we do the same for IPv4. > net/ipv4/syncookies.c | 1 + > net/ipv6/syncookies.c | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c > index 0905cf04c2a4..03ad8778c395 100644 > --- a/net/ipv4/syncookies.c > +++ b/net/ipv4/syncookies.c > @@ -335,6 +335,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) > treq->rcv_isn = ntohl(th->seq) - 1; > treq->snt_isn = cookie; > treq->ts_off = 0; > + treq->txhash = net_tx_rndhash(); > req->mss = mss; > ireq->ir_num = ntohs(th->dest); > ireq->ir_rmt_port = th->source; > diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c > index 7b75b0620730..4e7817abc0b9 100644 > --- a/net/ipv6/syncookies.c > +++ b/net/ipv6/syncookies.c > @@ -216,6 +216,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) > treq->rcv_isn = ntohl(th->seq) - 1; > treq->snt_isn = cookie; > treq->ts_off = 0; > + treq->txhash = net_tx_rndhash(); > > /* > * We need to lookup the dst_entry to get the correct window size. > -- > 2.13.2.932.g7449e964c-goog >
On Mon, 2017-07-17 at 12:35 +0200, Alexander Potapenko wrote: > KMSAN reported use of uninitialized memory in skb_set_hash_from_sk(), > which originated from the TCP request socket created in > cookie_v6_check(): > Similar error is reported for cookie_v4_check(). > > Signed-off-by: Alexander Potapenko <glider@google.com> > Fixes: 58d607d3e52f ("tcp: provide skb->hash to synack packets") Acked-by: Eric Dumazet <edumazet@google.com> Thanks !
From: Alexander Potapenko <glider@google.com> Date: Mon, 17 Jul 2017 12:35:58 +0200 > KMSAN reported use of uninitialized memory in skb_set_hash_from_sk(), > which originated from the TCP request socket created in > cookie_v6_check(): ... > Similar error is reported for cookie_v4_check(). > > Signed-off-by: Alexander Potapenko <glider@google.com> > Fixes: 58d607d3e52f ("tcp: provide skb->hash to synack packets") Applied and queued up for -stable, thanks!
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 0905cf04c2a4..03ad8778c395 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -335,6 +335,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) treq->rcv_isn = ntohl(th->seq) - 1; treq->snt_isn = cookie; treq->ts_off = 0; + treq->txhash = net_tx_rndhash(); req->mss = mss; ireq->ir_num = ntohs(th->dest); ireq->ir_rmt_port = th->source; diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index 7b75b0620730..4e7817abc0b9 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -216,6 +216,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) treq->rcv_isn = ntohl(th->seq) - 1; treq->snt_isn = cookie; treq->ts_off = 0; + treq->txhash = net_tx_rndhash(); /* * We need to lookup the dst_entry to get the correct window size.
KMSAN reported use of uninitialized memory in skb_set_hash_from_sk(), which originated from the TCP request socket created in cookie_v6_check(): ================================================================== BUG: KMSAN: use of uninitialized memory in tcp_transmit_skb+0xf77/0x3ec0 CPU: 1 PID: 2949 Comm: syz-execprog Not tainted 4.11.0-rc5+ #2931 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 TCP: request_sock_TCPv6: Possible SYN flooding on port 20028. Sending cookies. Check SNMP counters. Call Trace: <IRQ> __dump_stack lib/dump_stack.c:16 dump_stack+0x172/0x1c0 lib/dump_stack.c:52 kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:927 __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:469 skb_set_hash_from_sk ./include/net/sock.h:2011 tcp_transmit_skb+0xf77/0x3ec0 net/ipv4/tcp_output.c:983 tcp_send_ack+0x75b/0x830 net/ipv4/tcp_output.c:3493 tcp_delack_timer_handler+0x9a6/0xb90 net/ipv4/tcp_timer.c:284 tcp_delack_timer+0x1b0/0x310 net/ipv4/tcp_timer.c:309 call_timer_fn+0x240/0x520 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 __run_timers+0xc13/0xf10 kernel/time/timer.c:1601 run_timer_softirq+0x36/0xa0 kernel/time/timer.c:1614 __do_softirq+0x485/0x942 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 irq_exit+0x1fa/0x230 kernel/softirq.c:405 exiting_irq+0xe/0x10 ./arch/x86/include/asm/apic.h:657 smp_apic_timer_interrupt+0x5a/0x80 arch/x86/kernel/apic/apic.c:966 apic_timer_interrupt+0x86/0x90 arch/x86/entry/entry_64.S:489 RIP: 0010:native_restore_fl ./arch/x86/include/asm/irqflags.h:36 RIP: 0010:arch_local_irq_restore ./arch/x86/include/asm/irqflags.h:77 RIP: 0010:__msan_poison_alloca+0xed/0x120 mm/kmsan/kmsan_instr.c:440 RSP: 0018:ffff880024917cd8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000246 RBX: ffff8800224c0000 RCX: 0000000000000005 RDX: 0000000000000004 RSI: ffff880000000000 RDI: ffffea0000b6d770 RBP: ffff880024917d58 R08: 0000000000000dd8 R09: 0000000000000004 R10: 0000160000000000 R11: 0000000000000000 R12: ffffffff85abf810 R13: ffff880024917dd8 R14: 0000000000000010 R15: ffffffff81cabde4 </IRQ> poll_select_copy_remaining+0xac/0x6b0 fs/select.c:293 SYSC_select+0x4b4/0x4e0 fs/select.c:653 SyS_select+0x76/0xa0 fs/select.c:634 entry_SYSCALL_64_fastpath+0x13/0x94 arch/x86/entry/entry_64.S:204 RIP: 0033:0x4597e7 RSP: 002b:000000c420037ee0 EFLAGS: 00000246 ORIG_RAX: 0000000000000017 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004597e7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000c420037ef0 R08: 000000c420037ee0 R09: 0000000000000059 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000042dc20 R13: 00000000000000f3 R14: 0000000000000030 R15: 0000000000000003 chained origin: save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 kmsan_save_stack mm/kmsan/kmsan.c:317 kmsan_internal_chain_origin+0x12a/0x1f0 mm/kmsan/kmsan.c:547 __msan_store_shadow_origin_4+0xac/0x110 mm/kmsan/kmsan_instr.c:259 tcp_create_openreq_child+0x709/0x1ae0 net/ipv4/tcp_minisocks.c:472 tcp_v6_syn_recv_sock+0x7eb/0x2a30 net/ipv6/tcp_ipv6.c:1103 tcp_get_cookie_sock+0x136/0x5f0 net/ipv4/syncookies.c:212 cookie_v6_check+0x17a9/0x1b50 net/ipv6/syncookies.c:245 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989 tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298 tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487 ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279 NF_HOOK ./include/linux/netfilter.h:257 ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322 dst_input ./include/net/dst.h:492 ip6_rcv_finish net/ipv6/ip6_input.c:69 NF_HOOK ./include/linux/netfilter.h:257 ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203 __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208 __netif_receive_skb net/core/dev.c:4246 process_backlog+0x667/0xba0 net/core/dev.c:4866 napi_poll net/core/dev.c:5268 net_rx_action+0xc95/0x1590 net/core/dev.c:5333 __do_softirq+0x485/0x942 kernel/softirq.c:284 origin: save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:198 kmsan_kmalloc+0x7f/0xe0 mm/kmsan/kmsan.c:337 kmem_cache_alloc+0x1c2/0x1e0 mm/slub.c:2766 reqsk_alloc ./include/net/request_sock.h:87 inet_reqsk_alloc+0xa4/0x5b0 net/ipv4/tcp_input.c:6200 cookie_v6_check+0x4f4/0x1b50 net/ipv6/syncookies.c:169 tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:989 tcp_v6_do_rcv+0xdd8/0x1c60 net/ipv6/tcp_ipv6.c:1298 tcp_v6_rcv+0x41a3/0x4f00 net/ipv6/tcp_ipv6.c:1487 ip6_input_finish+0x82f/0x1ee0 net/ipv6/ip6_input.c:279 NF_HOOK ./include/linux/netfilter.h:257 ip6_input+0x239/0x290 net/ipv6/ip6_input.c:322 dst_input ./include/net/dst.h:492 ip6_rcv_finish net/ipv6/ip6_input.c:69 NF_HOOK ./include/linux/netfilter.h:257 ipv6_rcv+0x1dbd/0x22e0 net/ipv6/ip6_input.c:203 __netif_receive_skb_core+0x2f6f/0x3a20 net/core/dev.c:4208 __netif_receive_skb net/core/dev.c:4246 process_backlog+0x667/0xba0 net/core/dev.c:4866 napi_poll net/core/dev.c:5268 net_rx_action+0xc95/0x1590 net/core/dev.c:5333 __do_softirq+0x485/0x942 kernel/softirq.c:284 ================================================================== Similar error is reported for cookie_v4_check(). Signed-off-by: Alexander Potapenko <glider@google.com> Fixes: 58d607d3e52f ("tcp: provide skb->hash to synack packets") --- net/ipv4/syncookies.c | 1 + net/ipv6/syncookies.c | 1 + 2 files changed, 2 insertions(+)