On Mon, Feb 12, 2018 at 4:26 PM, Dmitry Vyukov <dvyu...@google.com> wrote: > On Mon, Feb 12, 2018 at 4:23 PM, syzbot > <syzbot+7d03c810e50aaedef...@syzkaller.appspotmail.com> wrote: >> Hello, >> >> syzbot hit the following crash on net-next commit >> 9515a2e082f91457db0ecff4b65371d0fb5d9aad (Thu Jan 25 03:37:38 2018 +0000) >> net/ipv4: Allow send to local broadcast from a socket bound to a VRF >> >> So far this crash happened 6 times on net-next. >> Unfortunately, I don't have any reproducer for this crash yet. >> Raw console output is attached. >> compiler: gcc (GCC) 7.1.1 20170620 >> .config is attached. > > > +xfrm maintainers
Here is a C repro: https://gist.githubusercontent.com/dvyukov/92c67ba9afaaa960bcfbdc6ef549ac10/raw/786f9221c1d707c7f4a15effcb1d5997dd4f8638/gistfile1.txt Somewhat messy, but it gives me: [64360.028053] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [a.out:7891] [64360.030043] Modules linked in: [64360.030355] CPU: 0 PID: 7891 Comm: a.out Not tainted 4.15.0+ #96 [64360.031334] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [64360.033632] RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x50 [64360.035114] RSP: 0018:ffff88006b96f6e0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11 [64360.037238] RAX: ffff8800636ce040 RBX: ffff880067fadb00 RCX: ffffffff84d147a6 [64360.039238] RDX: 0000000000000000 RSI: ffffffff84d147b0 RDI: 0000000000000001 [64360.041357] RBP: ffff88006b96f6e0 R08: ffff8800636ce040 R09: ffffed000d1008c9 [64360.043364] R10: 0000000000000000 R11: 0000000000000000 R12: ffffed000cff5b7b [64360.045366] R13: ffff880067fadbdc R14: ffff88006586ae00 R15: 0000000000000000 [64360.047367] FS: 00007f2a5bab5700(0000) GS:ffff88006ca00000(0000) knlGS:0000000000000000 [64360.049486] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [64360.051095] CR2: 0000000020cf9000 CR3: 00000000626a7001 CR4: 00000000001606f0 [64360.053065] Call Trace: [64360.053822] xfrm_confirm_neigh+0xd0/0x2c0 [64360.056166] raw_sendmsg+0x1f1e/0x2640 [64360.068396] inet_sendmsg+0x145/0x490 [64360.074198] sock_sendmsg+0xd2/0x120 [64360.075094] SYSC_sendto+0x3de/0x640 [64360.085269] SyS_sendto+0x40/0x50 >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+7d03c810e50aaedef...@syzkaller.appspotmail.com >> It will help syzbot understand when the bug is fixed. See footer for >> details. >> If you forward the report, please keep this part and the footer. >> >> INFO: rcu_sched self-detected stall on CPU >> 1-...!: (124998 ticks this GP) idle=376/140000000000001/0 >> softirq=506054/506054 fqs=19 >> (t=125000 jiffies g=289415 c=289414 q=312) >> rcu_sched kthread starved for 124920 jiffies! g289415 c289414 f0x0 >> RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 >> rcu_sched R running task 23456 8 2 0x80000000 >> Call Trace: >> context_switch kernel/sched/core.c:2799 [inline] >> __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 >> schedule+0xf5/0x430 kernel/sched/core.c:3434 >> schedule_timeout+0x118/0x230 kernel/time/timer.c:1793 >> rcu_gp_kthread+0x9e5/0x1930 kernel/rcu/tree.c:2314 >> kthread+0x33c/0x400 kernel/kthread.c:238 >> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:541 >> NMI backtrace for cpu 1 >> CPU: 1 PID: 15893 Comm: syz-executor0 Not tainted 4.15.0-rc9+ #210 >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >> Google 01/01/2011 >> Call Trace: >> <IRQ> >> __dump_stack lib/dump_stack.c:17 [inline] >> dump_stack+0x194/0x257 lib/dump_stack.c:53 >> nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 >> nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:62 >> arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 >> trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline] >> rcu_dump_cpu_stacks+0x186/0x1d9 kernel/rcu/tree.c:1459 >> print_cpu_stall kernel/rcu/tree.c:1608 [inline] >> check_cpu_stall.isra.61+0xbb8/0x15b0 kernel/rcu/tree.c:1676 >> __rcu_pending kernel/rcu/tree.c:3440 [inline] >> rcu_pending kernel/rcu/tree.c:3502 [inline] >> rcu_check_callbacks+0x256/0xd00 kernel/rcu/tree.c:2842 >> update_process_times+0x30/0x60 kernel/time/timer.c:1628 >> tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162 >> tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1194 >> __run_hrtimer kernel/time/hrtimer.c:1211 [inline] >> __hrtimer_run_queues+0x358/0xe20 kernel/time/hrtimer.c:1275 >> hrtimer_interrupt+0x1c2/0x5e0 kernel/time/hrtimer.c:1309 >> local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] >> smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050 >> apic_timer_interrupt+0xa9/0xb0 arch/x86/entry/entry_64.S:937 >> </IRQ> >> RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline] >> RIP: 0010:__sanitizer_cov_trace_pc+0x3b/0x50 kernel/kcov.c:106 >> RSP: 0018:ffff8801a6867820 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11 >> RAX: 0000000000010000 RBX: ffff8801caf7d200 RCX: ffffffff84acc87d >> RDX: 000000000000ffff RSI: ffffc90002aa6000 RDI: ffff8801c54c4f50 >> RBP: ffff8801a6867820 R08: 0000000000000001 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801c54c4e00 >> R13: dffffc0000000000 R14: ffffed00395efa5f R15: ffff8801caf7d2fc >> xfrm_get_dst_nexthop net/xfrm/xfrm_policy.c:2732 [inline] >> xfrm_confirm_neigh+0xad/0x270 net/xfrm/xfrm_policy.c:2759 >> dst_confirm_neigh include/net/dst.h:419 [inline] >> raw_sendmsg+0xece/0x23b0 net/ipv4/raw.c:702 >> inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764 >> sock_sendmsg_nosec net/socket.c:630 [inline] >> sock_sendmsg+0xca/0x110 net/socket.c:640 >> SYSC_sendto+0x361/0x5c0 net/socket.c:1747 >> SyS_sendto+0x40/0x50 net/socket.c:1715 >> entry_SYSCALL_64_fastpath+0x29/0xa0 >> RIP: 0033:0x452f19 >> RSP: 002b:00007f00a389ec58 EFLAGS: 00000212 ORIG_RAX: 000000000000002c >> RAX: ffffffffffffffda RBX: 000000000071bf58 RCX: 0000000000452f19 >> RDX: 000000000000001e RSI: 0000000020098000 RDI: 0000000000000013 >> RBP: 0000000000000510 R08: 0000000020cf9000 R09: 0000000000000010 >> R10: fffffffffffffffe R11: 0000000000000212 R12: 00000000006f6a20 >> R13: 00000000ffffffff R14: 00007f00a389f6d4 R15: 0000000000000001 >> >> >> --- >> This bug is generated by a dumb bot. It may contain errors. >> See https://goo.gl/tpsmEJ for details. >> Direct all questions to syzkal...@googlegroups.com. >> >> syzbot will keep track of this bug report. >> If you forgot to add the Reported-by tag, once the fix for this bug is >> merged >> into any tree, please reply to this email with: >> #syz fix: exact-commit-title >> To mark this as a duplicate of another syzbot report, please reply with: >> #syz dup: exact-subject-of-another-report >> If it's a one-off invalid bug report, please reply with: >> #syz invalid >> Note: if the crash happens again, it will cause creation of a new bug >> report. >> Note: all commands must start from beginning of the line in the email body. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "syzkaller-bugs" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to syzkaller-bugs+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/syzkaller-bugs/001a1141ba9ea381f70565057687%40google.com. >> For more options, visit https://groups.google.com/d/optout.
