syzbot


KMSAN: uninit-value in fib6_nh_release

Status: auto-closed as invalid on 2021/09/03 08:11
Subsystems: net
[Documentation on labels]
First crash: 1057d, last: 1057d

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in fib6_nh_flush_exceptions net/ipv6/route.c:1741 [inline]
BUG: KMSAN: uninit-value in fib6_nh_release+0x291/0x740 net/ipv6/route.c:3536
CPU: 1 PID: 15267 Comm: syz-executor.4 Tainted: G        W         5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 fib6_nh_flush_exceptions net/ipv6/route.c:1741 [inline]
 fib6_nh_release+0x291/0x740 net/ipv6/route.c:3536
 fib6_info_destroy_rcu+0x159/0x3d0 net/ipv6/ip6_fib.c:174
 rcu_do_batch kernel/rcu/tree.c:2559 [inline]
 rcu_core+0xf60/0x2070 kernel/rcu/tree.c:2794
 rcu_core_si+0xe/0x10 kernel/rcu/tree.c:2807
 __do_softirq+0x1b9/0x715 kernel/softirq.c:345
 invoke_softirq kernel/softirq.c:221 [inline]
 __irq_exit_rcu+0x22f/0x280 kernel/softirq.c:422
 irq_exit_rcu+0xe/0x10 kernel/softirq.c:434
 sysvec_apic_timer_interrupt+0xc6/0xf0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:650
RIP: 0010:finish_lock_switch+0x19a/0x1c0 kernel/sched/core.c:4080
Code: 40 c3 00 4d 85 e4 0f 85 f3 fe ff ff 48 83 7d c8 00 75 22 48 8b 5d c0 48 89 df e8 e1 3a c3 00 c6 00 00 c6 03 00 fb 48 83 c4 28 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 8b 7d d4 e8 93 40 c3 00 eb d4 8b
RSP: 0018:ffff888153667238 EFLAGS: 00000282
RAX: ffff88823fda6840 RBX: ffff88813fd95840 RCX: 000000023fd06840
RDX: ffff88823fd06840 RSI: 0000000000000270 RDI: ffff88813fd95840
RBP: ffff888153667260 R08: ffffea000000000f R09: ffff88813fffa000
R10: 000000008bee845a R11: 00000164ebab3cde R12: 0000000000000000
R13: ffff88813fd95840 R14: 0000000000000000 R15: 0000000000000000
 finish_task_switch+0xd8/0x2d0 kernel/sched/core.c:4202
 context_switch kernel/sched/core.c:4336 [inline]
 __schedule+0x54b/0x5c0 kernel/sched/core.c:5090
 preempt_schedule_common kernel/sched/core.c:5250 [inline]
 __cond_resched+0x43/0xa0 kernel/sched/core.c:6999
 _cond_resched include/linux/sched.h:1898 [inline]
 generic_perform_write+0x6bd/0xb00 mm/filemap.c:3592
 __generic_file_write_iter+0x52c/0xb80 mm/filemap.c:3704
 generic_file_write_iter+0x171/0x450 mm/filemap.c:3736
 do_iter_readv_writev+0xa99/0xc30 include/linux/fs.h:1971
 do_iter_write+0x371/0x1090 fs/read_write.c:866
 vfs_iter_write+0x118/0x180 fs/read_write.c:907
 iter_file_splice_write+0xdfb/0x1b20 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x1a4/0x240 fs/splice.c:936
 splice_direct_to_actor+0x90d/0x14c0 fs/splice.c:891
 do_splice_direct+0x3a1/0x5f0 fs/splice.c:979
 do_sendfile+0x1ae9/0x2ae0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64+0x321/0x3d0 fs/read_write.c:1311
 __x64_sys_sendfile64+0x56/0x70 fs/read_write.c:1311
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd68f22c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000ef85 R11: 0000000000000246 R12: 000000000056bf60
R13: 0000000000a9fb1f R14: 00007fd68f22c300 R15: 0000000000022000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8e/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2922 [inline]
 slab_alloc mm/slub.c:2931 [inline]
 kmem_cache_alloc_trace+0x8c7/0x1030 mm/slub.c:2948
 kmalloc include/linux/slab.h:554 [inline]
 batadv_forw_packet_alloc+0x28b/0x820 net/batman-adv/send.c:525
 batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:562 [inline]
 batadv_iv_ogm_queue_add+0x14a6/0x1c40 net/batman-adv/bat_iv_ogm.c:670
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:849 [inline]
 batadv_iv_ogm_schedule+0x12cd/0x16b0 net/batman-adv/bat_iv_ogm.c:869
 batadv_iv_send_outstanding_bat_ogm_packet+0xd6e/0xef0 net/batman-adv/bat_iv_ogm.c:1723
 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2275
 worker_thread+0x10ec/0x2340 kernel/workqueue.c:2421
 kthread+0x521/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
=====================================================
BUG: kernel NULL pointer dereference, address: 000000000000003c
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 154e3a067 P4D 154e3a067 PUD 150795067 PMD 0 
Oops: 0000 [#1] SMP
CPU: 1 PID: 15267 Comm: syz-executor.4 Tainted: G    B   W         5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:fib6_nh_flush_exceptions net/ipv6/route.c:1741 [inline]
RIP: 0010:fib6_nh_release+0x103/0x740 net/ipv6/route.c:3536
Code: 96 f4 48 8b 4d c0 48 89 08 48 85 c9 0f 85 a6 05 00 00 4c 89 3b 31 db 4d 89 ef 48 83 7d c0 00 0f 85 8b 01 00 00 66 90 89 5d c8 <4d> 8b 27 4c 89 7d b0 4c 89 ff e8 ee 5f 96 f4 4c 8b 28 44 8b 32 4d
RSP: 0018:ffff88813fd05d58 EFLAGS: 00010282
RAX: ffff88813fd27b00 RBX: 0000000000000000 RCX: ffff888154fcddc0
RDX: ffffffff92456000 RSI: 0000000000000000 RDI: ffffffff92455b90
RBP: ffff88813fd05dc8 R08: ffffffff8165313c R09: 00000000ffffdfff
R10: 6f6c20676e696c00 R11: 6e696c6261736944 R12: ffff88813fd27b00
R13: 000000000000003c R14: ffff8881503a2ab8 R15: 000000000000003c
FS:  00007fd68f22c700(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000003c CR3: 0000000151efe000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 fib6_info_destroy_rcu+0x159/0x3d0 net/ipv6/ip6_fib.c:174
 rcu_do_batch kernel/rcu/tree.c:2559 [inline]
 rcu_core+0xf60/0x2070 kernel/rcu/tree.c:2794
 rcu_core_si+0xe/0x10 kernel/rcu/tree.c:2807
 __do_softirq+0x1b9/0x715 kernel/softirq.c:345
 invoke_softirq kernel/softirq.c:221 [inline]
 __irq_exit_rcu+0x22f/0x280 kernel/softirq.c:422
 irq_exit_rcu+0xe/0x10 kernel/softirq.c:434
 sysvec_apic_timer_interrupt+0xc6/0xf0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:650
RIP: 0010:finish_lock_switch+0x19a/0x1c0 kernel/sched/core.c:4080
Code: 40 c3 00 4d 85 e4 0f 85 f3 fe ff ff 48 83 7d c8 00 75 22 48 8b 5d c0 48 89 df e8 e1 3a c3 00 c6 00 00 c6 03 00 fb 48 83 c4 28 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 8b 7d d4 e8 93 40 c3 00 eb d4 8b
RSP: 0018:ffff888153667238 EFLAGS: 00000282
RAX: ffff88823fda6840 RBX: ffff88813fd95840 RCX: 000000023fd06840
RDX: ffff88823fd06840 RSI: 0000000000000270 RDI: ffff88813fd95840
RBP: ffff888153667260 R08: ffffea000000000f R09: ffff88813fffa000
R10: 000000008bee845a R11: 00000164ebab3cde R12: 0000000000000000
R13: ffff88813fd95840 R14: 0000000000000000 R15: 0000000000000000
 finish_task_switch+0xd8/0x2d0 kernel/sched/core.c:4202
 context_switch kernel/sched/core.c:4336 [inline]
 __schedule+0x54b/0x5c0 kernel/sched/core.c:5090
 preempt_schedule_common kernel/sched/core.c:5250 [inline]
 __cond_resched+0x43/0xa0 kernel/sched/core.c:6999
 _cond_resched include/linux/sched.h:1898 [inline]
 generic_perform_write+0x6bd/0xb00 mm/filemap.c:3592
 __generic_file_write_iter+0x52c/0xb80 mm/filemap.c:3704
 generic_file_write_iter+0x171/0x450 mm/filemap.c:3736
 do_iter_readv_writev+0xa99/0xc30 include/linux/fs.h:1971
 do_iter_write+0x371/0x1090 fs/read_write.c:866
 vfs_iter_write+0x118/0x180 fs/read_write.c:907
 iter_file_splice_write+0xdfb/0x1b20 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x1a4/0x240 fs/splice.c:936
 splice_direct_to_actor+0x90d/0x14c0 fs/splice.c:891
 do_splice_direct+0x3a1/0x5f0 fs/splice.c:979
 do_sendfile+0x1ae9/0x2ae0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64+0x321/0x3d0 fs/read_write.c:1311
 __x64_sys_sendfile64+0x56/0x70 fs/read_write.c:1311
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd68f22c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000ef85 R11: 0000000000000246 R12: 000000000056bf60
R13: 0000000000a9fb1f R14: 00007fd68f22c300 R15: 0000000000022000
Modules linked in:
CR2: 000000000000003c
---[ end trace 37420b41cd99095b ]---
RIP: 0010:fib6_nh_flush_exceptions net/ipv6/route.c:1741 [inline]
RIP: 0010:fib6_nh_release+0x103/0x740 net/ipv6/route.c:3536
Code: 96 f4 48 8b 4d c0 48 89 08 48 85 c9 0f 85 a6 05 00 00 4c 89 3b 31 db 4d 89 ef 48 83 7d c0 00 0f 85 8b 01 00 00 66 90 89 5d c8 <4d> 8b 27 4c 89 7d b0 4c 89 ff e8 ee 5f 96 f4 4c 8b 28 44 8b 32 4d
RSP: 0018:ffff88813fd05d58 EFLAGS: 00010282
RAX: ffff88813fd27b00 RBX: 0000000000000000 RCX: ffff888154fcddc0
RDX: ffffffff92456000 RSI: 0000000000000000 RDI: ffffffff92455b90
RBP: ffff88813fd05dc8 R08: ffffffff8165313c R09: 00000000ffffdfff
R10: 6f6c20676e696c00 R11: 6e696c6261736944 R12: ffff88813fd27b00
R13: 000000000000003c R14: ffff8881503a2ab8 R15: 000000000000003c
FS:  00007fd68f22c700(0000) GS:ffff88813fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000003c CR3: 0000000151efe000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/05/07 10:31 https://github.com/google/kmsan.git master 4ebaab5fb428 f6da8120 .config console log report info ci-upstream-kmsan-gce KMSAN: uninit-value in fib6_nh_release
* Struck through repros no longer work on HEAD.