syzbot


BUG: soft lockup in netlink_sendmsg

Status: upstream: reported C repro on 2021/04/02 18:46
Reported-by: syzbot+e1d9f8a36ecb96e1faaf@syzkaller.appspotmail.com
First crash: 612d, last: 218d

Fix bisection: failed (bisect log)
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 BUG: soft lockup in netlink_sendmsg 1 328d 328d 0/1 auto-closed as invalid on 2022/05/11 11:30
upstream INFO: rcu detected stall in netlink_sendmsg (4) C done error 37 6d15h 979d 0/24 upstream: reported C repro on 2020/03/31 17:43

Sample crash report:
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [syz-executor970:8348]
Modules linked in:
irq event stamp: 293077
hardirqs last  enabled at (293076): [<ffffffff815471c5>] seqcount_lockdep_reader_access include/linux/seqlock.h:83 [inline]
hardirqs last  enabled at (293076): [<ffffffff815471c5>] read_seqcount_begin include/linux/seqlock.h:164 [inline]
hardirqs last  enabled at (293076): [<ffffffff815471c5>] ktime_get+0x235/0x2f0 kernel/time/timekeeping.c:756
hardirqs last disabled at (293077): [<ffffffff81003d00>] trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last  enabled at (60): [<ffffffff869fd8d6>] netlink_insert+0x156/0x11d0 net/netlink/af_netlink.c:603
softirqs last disabled at (68): [<ffffffff86759742>] __dev_queue_xmit+0x1e2/0x2e00 net/core/dev.c:3773
CPU: 0 PID: 8348 Comm: syz-executor970 Not tainted 4.19.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:cake_heapify+0x2cd/0x340 net/sched/sch_cake.c:1403
Code: e8 38 d5 ca fa 44 0f b7 6c 24 06 89 ee 44 89 ef e8 18 d6 ca fa 41 39 ed 0f 85 45 fe ff ff 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e <41> 5f e9 0c d5 ca fa e8 b7 95 00 fb e9 fc fd ff ff e8 1d 95 00 fb
RSP: 0018:ffff888095f07670 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff8880922b07c0 RCX: ffffffff86978838
RDX: 0000000000000932 RSI: ffff8880ade9e0c0 RDI: 0000000000000004
RBP: dffffc0000000000 R08: ffffffff8c663018 R09: 0000000000000932
R10: 0000000000000004 R11: ffffffff8c66301b R12: 0000000000000931
R13: 0000000000000300 R14: ffff88808a800180 R15: dffffc0000000000
FS:  00007fef04876700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000a18d4000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 cake_drop net/sched/sch_cake.c:1468 [inline]
 cake_enqueue+0x1296/0x33d0 net/sched/sch_cake.c:1844
 __dev_xmit_skb net/core/dev.c:3494 [inline]
 __dev_queue_xmit+0x140a/0x2e00 net/core/dev.c:3807
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:303 [inline]
 __netlink_deliver_tap net/netlink/af_netlink.c:321 [inline]
 netlink_deliver_tap+0x8fb/0xb00 net/netlink/af_netlink.c:334
 netlink_deliver_tap_kernel net/netlink/af_netlink.c:343 [inline]
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x545/0x690 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x6bb/0xc40 net/netlink/af_netlink.c:1909
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xc3/0x120 net/socket.c:632
 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2115
 __sys_sendmsg net/socket.c:2153 [inline]
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4519b9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 91 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fef04876318 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004d04d8 RCX: 00000000004519b9
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000005
RBP: 00000000004d04d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000049f7f0
R13: 00007ffc1b725baf R14: 00007fef04876400 R15: 0000000000022000
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60

Crashes (7):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2021/04/02 22:22 linux-4.19.y 2034d6f0838e 6a81331a .config log report syz C BUG: soft lockup in netlink_sendmsg
ci2-linux-4-19 2022/05/01 13:37 linux-4.19.y 3f8a27f9e27b 2df221f6 .config log report info BUG: soft lockup in netlink_sendmsg
ci2-linux-4-19 2022/04/16 09:02 linux-4.19.y 3f8a27f9e27b 8bcc32a6 .config log report info BUG: soft lockup in netlink_sendmsg
ci2-linux-4-19 2022/04/02 22:23 linux-4.19.y 3f8a27f9e27b 79a2a8fc .config log report info BUG: soft lockup in netlink_sendmsg
ci2-linux-4-19 2022/03/24 12:19 linux-4.19.y 3f8a27f9e27b 89bc8608 .config log report info BUG: soft lockup in netlink_sendmsg
ci2-linux-4-19 2022/01/15 14:40 linux-4.19.y 3f8a27f9e27b 723cfaf0 .config log report info BUG: soft lockup in netlink_sendmsg
ci2-linux-4-19 2021/04/02 18:45 linux-4.19.y 2034d6f0838e 6a81331a .config log report info BUG: soft lockup in netlink_sendmsg
* Struck through repros no longer work on HEAD.