syzbot


general protection fault in taprio_dequeue_soft

Status: fixed on 2021/03/10 01:49
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+8971da381fb5a31f542d@syzkaller.appspotmail.com
Fix commit: 44d4775ca518 net/sched: sch_taprio: reset child qdiscs before freeing them
First crash: 1251d, last: 1251d
Cause bisection: introduced by (bisect log) :
commit b5b73b26b3ca34574124ed7ae9c5ba8391a7f176
Author: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Date: Thu Sep 10 00:03:11 2020 +0000

  taprio: Fix allowing too small intervals

Crash: BUG: unable to handle kernel NULL pointer dereference in taprio_dequeue_soft (log)
Repro: C syz .config
  
Discussions (4)
Title Replies (including bot) Last reply
[PATCH 5.4 00/47] 5.4.87-rc1 review 58 (58) 2021/02/26 14:21
[PATCH 5.10 00/63] 5.10.5-rc1 review 75 (75) 2021/01/07 08:13
[PATCH net] net/sched: sch_taprio: reset child qdiscs before freeing them 7 (7) 2020/12/17 20:49
general protection fault in taprio_dequeue_soft 1 (3) 2020/12/16 12:55
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in taprio_dequeue_soft (2) net 1 897d 897d 0/26 closed as invalid on 2022/01/07 18:56
Last patch testing requests (1)
Created Duration User Patch Repo Result
2020/12/16 14:38 13m dcaratti@redhat.com patch net-old report log

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.10.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:taprio_dequeue_soft+0x22e/0xa40 net/sched/sch_taprio.c:544
Code: 24 18 e8 d5 3e 4c fa 48 8b 44 24 10 80 38 00 0f 85 4c 07 00 00 48 8b 93 c0 02 00 00 49 63 c5 4c 8d 24 c2 4c 89 e0 48 c1 e8 03 <80> 3c 28 00 0f 85 3c 07 00 00 4d 8b 24 24 4d 85 e4 0f 84 87 03 00
RSP: 0018:ffffc90000d90e08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880282e3800 RCX: ffffffff8723c557
RDX: 0000000000000000 RSI: ffffffff8723c59b RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8ebaf667
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000401 R15: ffff88801917e000
FS:  0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000600 CR3: 0000000013cdc000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 dequeue_skb net/sched/sch_generic.c:263 [inline]
 qdisc_restart net/sched/sch_generic.c:366 [inline]
 __qdisc_run+0x1ae/0x15e0 net/sched/sch_generic.c:384
 qdisc_run include/net/pkt_sched.h:131 [inline]
 qdisc_run include/net/pkt_sched.h:123 [inline]
 net_tx_action+0x4b9/0xbf0 net/core/dev.c:4915
 __do_softirq+0x2a0/0x9f6 kernel/softirq.c:298
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu kernel/softirq.c:423 [inline]
 irq_exit_rcu+0x132/0x200 kernel/softirq.c:435
 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:79 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:169 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
RIP: 0010:acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:517
Code: 5d 07 88 f8 84 db 75 ac e8 44 0f 88 f8 e8 bf cd 8d f8 e9 0c 00 00 00 e8 35 0f 88 f8 0f 00 2d 9e 86 c0 00 e8 29 0f 88 f8 fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 84 07 88 f8 48 85 db
RSP: 0018:ffffc90000d27d18 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff19d8e91
RDX: ffff888010d98000 RSI: ffffffff88e7f547 RDI: 0000000000000000
RBP: ffff888014e50064 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001
R13: ffff888014e50000 R14: ffff888014e50064 R15: ffff88801747a804
 acpi_idle_enter+0x361/0x500 drivers/acpi/processor_idle.c:648
 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x3e1/0x590 kernel/sched/idle.c:299
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:395
 start_secondary+0x266/0x340 arch/x86/kernel/smpboot.c:266
 secondary_startup_64_no_verify+0xb0/0xbb
Modules linked in:
---[ end trace 86b7dd17b9a0a261 ]---
RIP: 0010:taprio_dequeue_soft+0x22e/0xa40 net/sched/sch_taprio.c:544
Code: 24 18 e8 d5 3e 4c fa 48 8b 44 24 10 80 38 00 0f 85 4c 07 00 00 48 8b 93 c0 02 00 00 49 63 c5 4c 8d 24 c2 4c 89 e0 48 c1 e8 03 <80> 3c 28 00 0f 85 3c 07 00 00 4d 8b 24 24 4d 85 e4 0f 84 87 03 00
RSP: 0018:ffffc90000d90e08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880282e3800 RCX: ffffffff8723c557
RDX: 0000000000000000 RSI: ffffffff8723c59b RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8ebaf667
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000401 R15: ffff88801917e000
FS:  0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000600 CR3: 0000000013cdc000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/12/15 06:32 net-old 7f376f1917d7 97183ed7 .config console log report syz C ci-upstream-net-this-kasan-gce
2020/12/15 08:35 net-next-old 7bca5021a4e6 97183ed7 .config console log report syz C ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.