syzbot


WARNING: suspicious RCU usage in hash_ip4_destroy

Status: closed as invalid on 2024/02/01 08:52
Subsystems: netfilter
[Documentation on labels]
First crash: 376d, last: 376d
Cause bisection: introduced by (bisect log) :
commit 080898f8e782734987f127c73a69ebeab7b5f5e8
Author: Jozsef Kadlecsik <kadlec@netfilter.org>
Date: Tue Jan 16 16:29:56 2024 +0000

  netfilter: ipset: fix performance regression in swap operation

Crash: WARNING: suspicious RCU usage in hash_ip4_destroy (log)
Repro: C syz .config
  

Sample crash report:
=============================
WARNING: suspicious RCU usage
6.7.0-next-20240118-syzkaller #0 Not tainted
-----------------------------
net/netfilter/ipset/ip_set_hash_gen.h:456 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syz-executor319/5063:
 #0: ffffffff8f0b0128 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:697 [inline]
 #0: ffffffff8f0b0128 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3e/0x250 drivers/net/tun.c:3499
 #1: ffffffff8d7e0e38 (sysctl_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #1: ffffffff8d7e0e38 (sysctl_lock){+.+.}-{2:2}, at: start_unregistering fs/proc/proc_sysctl.c:313 [inline]
 #1: ffffffff8d7e0e38 (sysctl_lock){+.+.}-{2:2}, at: drop_sysctl_table+0x17c/0x3c0 fs/proc/proc_sysctl.c:1498
 #2: ffffffff8d5aeb00 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #2: ffffffff8d5aeb00 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2152 [inline]
 #2: ffffffff8d5aeb00 (rcu_callback){....}-{0:0}, at: rcu_core+0x7cc/0x16b0 kernel/rcu/tree.c:2433

stack backtrace:
CPU: 1 PID: 5063 Comm: syz-executor319 Not tainted 6.7.0-next-20240118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x125/0x1b0 lib/dump_stack.c:106
 lockdep_rcu_suspicious+0x20b/0x3b0 kernel/locking/lockdep.c:6712
 hash_ip4_destroy+0x320/0x420 net/netfilter/ipset/ip_set_hash_gen.h:456
 ip_set_destroy_set+0x65/0x100 net/netfilter/ipset/ip_set_core.c:1180
 rcu_do_batch kernel/rcu/tree.c:2158 [inline]
 rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2433
 __do_softirq+0x218/0x8de kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb9/0x120 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1076
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:write_comp_data+0x0/0x90 kernel/kcov.c:230
Code: 48 8b 05 03 a7 77 7e 48 8b 80 f0 15 00 00 c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <49> 89 d2 49 89 f8 49 89 f1 65 48 8b 15 cf a6 77 7e 65 8b 05 d0 a6
RSP: 0018:ffffc900036ef2e0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffc900036ef368 RCX: ffffffff813c1ff2
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000002 R12: ffffc900036efa78
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000001
 deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline]
 unwind_next_frame+0x1aa2/0x2390 arch/x86/kernel/unwind_orc.c:648
 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xba/0x110 mm/kasan/generic.c:586
 kvfree_call_rcu+0x74/0xbe0 kernel/rcu/tree.c:3402
 drop_sysctl_table+0x1d4/0x3c0 fs/proc/proc_sysctl.c:1502
 unregister_sysctl_table fs/proc/proc_sysctl.c:1523 [inline]
 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1515
 neigh_sysctl_unregister+0x5f/0x80 net/core/neighbour.c:3880
 addrconf_ifdown.isra.0+0x1638/0x1c60 net/ipv6/addrconf.c:3949
 addrconf_notify+0x223/0x18f0 net/ipv6/addrconf.c:3719
 notifier_call_chain+0xb9/0x3e0 kernel/notifier.c:93
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1966
 call_netdevice_notifiers_extack net/core/dev.c:2004 [inline]
 call_netdevice_notifiers net/core/dev.c:2018 [inline]
 unregister_netdevice_many_notify+0x8ad/0x1a10 net/core/dev.c:11083
 unregister_netdevice_many net/core/dev.c:11139 [inline]
 unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11019
 unregister_netdevice include/linux/netdevice.h:3195 [inline]
 __tun_detach+0x1170/0x1470 drivers/net/tun.c:684
 tun_detach drivers/net/tun.c:700 [inline]
 tun_chr_close+0xc8/0x250 drivers/net/tun.c:3499
 __fput+0x270/0xb80 fs/file_table.c:376
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa7d/0x2ac0 kernel/exit.c:871
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1020
 __do_sys_exit_group kernel/exit.c:1031 [inline]
 __se_sys_exit_group kernel/exit.c:1029 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1029
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fd06eb0c289
Code: Unable to access opcode bytes at 0x7fd06eb0c25f.
RSP: 002b:00007fff0b955448 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fd06eb0c289
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007fd06eb8d390 R08: ffffffffffffffb8 R09: bb1414ac00000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd06eb8d390
R13: 0000000000000000 R14: 00007fd06eb8ee60 R15: 00007fd06eadd4c0
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 8b 05 03 a7 77 7e 	mov    0x7e77a703(%rip),%rax        # 0x7e77a70a
   7:	48 8b 80 f0 15 00 00 	mov    0x15f0(%rax),%rax
   e:	c3                   	ret
   f:	cc                   	int3
  10:	cc                   	int3
  11:	cc                   	int3
  12:	cc                   	int3
  13:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	90                   	nop
  1f:	90                   	nop
  20:	90                   	nop
  21:	90                   	nop
  22:	90                   	nop
  23:	90                   	nop
  24:	90                   	nop
  25:	90                   	nop
  26:	90                   	nop
  27:	90                   	nop
  28:	90                   	nop
  29:	90                   	nop
* 2a:	49 89 d2             	mov    %rdx,%r10 <-- trapping instruction
  2d:	49 89 f8             	mov    %rdi,%r8
  30:	49 89 f1             	mov    %rsi,%r9
  33:	65 48 8b 15 cf a6 77 	mov    %gs:0x7e77a6cf(%rip),%rdx        # 0x7e77a70a
  3a:	7e
  3b:	65                   	gs
  3c:	8b                   	.byte 0x8b
  3d:	05                   	.byte 0x5
  3e:	d0                   	.byte 0xd0
  3f:	a6                   	cmpsb  %es:(%rdi),%ds:(%rsi)

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/01/18 21:58 linux-next 2863b714f3ad 239abf84 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in hash_ip4_destroy
2024/01/18 19:36 linux-next 2863b714f3ad 239abf84 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in hash_ip4_destroy
2024/01/18 16:26 linux-next 2863b714f3ad 239abf84 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in hash_ip4_destroy
2024/01/18 07:39 linux-next 2863b714f3ad 915053c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in hash_ip4_destroy
2024/01/18 06:56 linux-next 2863b714f3ad 915053c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING: suspicious RCU usage in hash_ip4_destroy
* Struck through repros no longer work on HEAD.