syzbot


KMSAN: uninit-value in consume_skb

Status: closed as invalid on 2019/10/08 12:18
Subsystems: net virtualization
[Documentation on labels]
First crash: 1669d, last: 1669d

Sample crash report:
==================================================================
BUG: KMSAN: uninit-value in skb_unref include/linux/skbuff.h:1017 [inline]
BUG: KMSAN: uninit-value in consume_skb+0x223/0x2e0 net/core/skbuff.c:834
CPU: 1 PID: 13688 Comm: syz-executor.4 Not tainted 5.3.0-rc6+ #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x162/0x2d0 mm/kmsan/kmsan_report.c:109
 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:294
 skb_unref include/linux/skbuff.h:1017 [inline]
 consume_skb+0x223/0x2e0 net/core/skbuff.c:834
 __dev_kfree_skb_any+0x32e/0x360 net/core/dev.c:2823
 dev_consume_skb_any include/linux/netdevice.h:3611 [inline]
 napi_consume_skb+0x27e/0x5d0 net/core/skbuff.c:902
 free_old_xmit_skbs+0x1a1/0x450 drivers/net/virtio_net.c:1366
 start_xmit+0x1b6/0x20c0 drivers/net/virtio_net.c:1562
 __netdev_start_xmit include/linux/netdevice.h:4406 [inline]
 netdev_start_xmit include/linux/netdevice.h:4420 [inline]
 xmit_one net/core/dev.c:3280 [inline]
 dev_hard_start_xmit+0x51a/0xab0 net/core/dev.c:3296
 sch_direct_xmit+0x56c/0x18c0 net/sched/sch_generic.c:309
 __dev_xmit_skb net/core/dev.c:3477 [inline]
 __dev_queue_xmit+0x1e53/0x4270 net/core/dev.c:3838
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x20c6/0x25d0 net/ipv4/ip_output.c:228
 __ip_finish_output+0xaf8/0xda0 net/ipv4/ip_output.c:308
 ip_finish_output+0x2db/0x420 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0x541/0x610 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out net/ipv4/ip_output.c:125 [inline]
 __ip_queue_xmit+0x1caf/0x21f0 net/ipv4/ip_output.c:532
 ip_queue_xmit+0xcc/0xf0 include/net/ip.h:236
 __tcp_transmit_skb+0x409e/0x5c60 net/ipv4/tcp_output.c:1158
 __tcp_send_ack+0x701/0x840 net/ipv4/tcp_output.c:3684
 tcp_send_ack+0x68/0x90 net/ipv4/tcp_output.c:3690
 __tcp_ack_snd_check+0x643/0xb40 net/ipv4/tcp_input.c:5197
 tcp_rcv_established+0x2d7b/0x31f0 net/ipv4/tcp_input.c:5628
 tcp_v4_do_rcv+0x684/0xd70 net/ipv4/tcp_ipv4.c:1542
 tcp_v4_rcv+0x64fb/0x6af0 net/ipv4/tcp_ipv4.c:1923
 ip_protocol_deliver_rcu+0x541/0xbc0 net/ipv4/ip_input.c:204
 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip_local_deliver+0x62a/0x7c0 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:413 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip_rcv+0x6c5/0x740 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core net/core/dev.c:5004 [inline]
 __netif_receive_skb net/core/dev.c:5118 [inline]
 netif_receive_skb_internal+0x8f4/0xc20 net/core/dev.c:5208
 napi_skb_finish net/core/dev.c:5671 [inline]
 napi_gro_receive+0x682/0xb90 net/core/dev.c:5704
 receive_buf+0x653b/0x8810 drivers/net/virtio_net.c:1061
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x666/0x19d0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6352 [inline]
 net_rx_action+0x74b/0x1950 net/core/dev.c:6418
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x230/0x280 kernel/softirq.c:416
 exiting_irq arch/x86/include/asm/apic.h:537 [inline]
 do_IRQ+0x20d/0x3a0 arch/x86/kernel/irq.c:259
 common_interrupt+0x2e/0x2e arch/x86/entry/entry_64.S:612
 </IRQ>
RIP: 0010:__msan_poison_alloca+0x5f/0x270 mm/kmsan/kmsan_instr.c:248
Code: fe 7d 85 c0 0f 85 d8 01 00 00 49 89 d7 49 89 fc 48 89 74 24 08 48 85 f6 74 65 44 89 e0 25 ff 0f 00 00 bb 00 10 00 00 48 29 c3 <4c> 8b 74 24 08 4c 39 f3 49 0f 43 de 4d 89 e5 66 90 4c 89 ef 48 89
RSP: 0018:ffff8880327ffc80 EFLAGS: 00000216 ORIG_RAX: ffffffffffffffd7
RAX: 0000000000000d34 RBX: 00000000000002cc RCX: ccccccccccccd000
RDX: ffffffff8f815300 RSI: 0000000000000004 RDI: ffff8880327ffd34
RBP: ffff8880327ffd00 R08: ffffea000000000f R09: ffff88812fffb000
R10: 0000000000000004 R11: ffffffff81df6320 R12: ffff8880327ffd34
R13: 0000000000000000 R14: ffff8880569289a0 R15: ffffffff8f815300
 lockref_put_or_lock+0x6f/0x390 lib/lockref.c:166
 fast_dput fs/dcache.c:728 [inline]
 dput+0x409/0x1010 fs/dcache.c:846
 path_put fs/namei.c:482 [inline]
 do_unlinkat+0xaf3/0xf00 fs/namei.c:4078
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink+0x8a/0xa0 fs/namei.c:4108
 __x64_sys_unlink+0x32/0x50 fs/namei.c:4108
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x4595c7
Code: 00 66 90 b8 58 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 9d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 7d ba fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:0000000000a6ecb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004595c7
RDX: 0000000000a6ecd0 RSI: 0000000000a6ecd0 RDI: 0000000000a6ed60
RBP: 00000000000011b9 R08: 0000000000000000 R09: 0000000000000011
R10: 000000000000000a R11: 0000000000000246 R12: 0000000000a6fdf0
R13: 0000555556a84940 R14: 0000000000000000 R15: 0000000000a6fdf0

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:187 [inline]
 kmsan_internal_poison_shadow+0x53/0xa0 mm/kmsan/kmsan.c:146
 kmsan_slab_free+0x8d/0x100 mm/kmsan/kmsan_hooks.c:195
 slab_free_freelist_hook mm/slub.c:1472 [inline]
 slab_free mm/slub.c:3038 [inline]
 kmem_cache_free+0x2d1/0x2b70 mm/slub.c:3054
 kfree_skbmem net/core/skbuff.c:644 [inline]
 __kfree_skb net/core/skbuff.c:680 [inline]
 kfree_skb+0x473/0x4c0 net/core/skbuff.c:697
 packet_rcv_spkt+0x719/0x840 net/packet/af_packet.c:1847
 dev_queue_xmit_nit+0x1125/0x1200 net/core/dev.c:2077
 xmit_one net/core/dev.c:3276 [inline]
 dev_hard_start_xmit+0x21e/0xab0 net/core/dev.c:3296
 sch_direct_xmit+0x56c/0x18c0 net/sched/sch_generic.c:309
 __dev_xmit_skb net/core/dev.c:3477 [inline]
 __dev_queue_xmit+0x1e53/0x4270 net/core/dev.c:3838
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x20c6/0x25d0 net/ipv4/ip_output.c:228
 __ip_finish_output+0xaf8/0xda0 net/ipv4/ip_output.c:308
 ip_finish_output+0x2db/0x420 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0x541/0x610 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out net/ipv4/ip_output.c:125 [inline]
 __ip_queue_xmit+0x1caf/0x21f0 net/ipv4/ip_output.c:532
 ip_queue_xmit+0xcc/0xf0 include/net/ip.h:236
 __tcp_transmit_skb+0x409e/0x5c60 net/ipv4/tcp_output.c:1158
 __tcp_send_ack+0x701/0x840 net/ipv4/tcp_output.c:3684
 tcp_send_ack+0x68/0x90 net/ipv4/tcp_output.c:3690
 __tcp_ack_snd_check+0x643/0xb40 net/ipv4/tcp_input.c:5197
 tcp_rcv_established+0x2d7b/0x31f0 net/ipv4/tcp_input.c:5628
 tcp_v4_do_rcv+0x684/0xd70 net/ipv4/tcp_ipv4.c:1542
 tcp_v4_rcv+0x64fb/0x6af0 net/ipv4/tcp_ipv4.c:1923
 ip_protocol_deliver_rcu+0x541/0xbc0 net/ipv4/ip_input.c:204
 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip_local_deliver+0x62a/0x7c0 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:413 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ip_rcv+0x6c5/0x740 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core net/core/dev.c:5004 [inline]
 __netif_receive_skb net/core/dev.c:5118 [inline]
 netif_receive_skb_internal+0x8f4/0xc20 net/core/dev.c:5208
 napi_skb_finish net/core/dev.c:5671 [inline]
 napi_gro_receive+0x682/0xb90 net/core/dev.c:5704
 receive_buf+0x653b/0x8810 drivers/net/virtio_net.c:1061
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x666/0x19d0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6352 [inline]
 net_rx_action+0x74b/0x1950 net/core/dev.c:6418
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x230/0x280 kernel/softirq.c:416
 exiting_irq arch/x86/include/asm/apic.h:537 [inline]
 do_IRQ+0x20d/0x3a0 arch/x86/kernel/irq.c:259
 ret_from_intr+0x0/0x33
 __msan_poison_alloca+0x5f/0x270 mm/kmsan/kmsan_instr.c:248
 lockref_put_or_lock+0x6f/0x390 lib/lockref.c:166
 fast_dput fs/dcache.c:728 [inline]
 dput+0x409/0x1010 fs/dcache.c:846
 path_put fs/namei.c:482 [inline]
 do_unlinkat+0xaf3/0xf00 fs/namei.c:4078
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink+0x8a/0xa0 fs/namei.c:4108
 __x64_sys_unlink+0x32/0x50 fs/namei.c:4108
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/09/02 05:24 https://github.com/google/kmsan.git master e88bfb817dca db7c31ca .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.