Re: [linus:master] [sched/eevdf] 2227a957e1: BUG:kernel_NULL_pointer_dereference,address

From: Oliver Sang
Date: Tue Jan 30 2024 - 09:10:34 EST

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hi, Abel,

On Tue, Jan 30, 2024 at 06:13:32PM +0800, Abel Wu wrote:
> On 1/30/24 3:24 PM, kernel test robot Wrote:
> >
> >
> > Hello,
> >
> > (besides a previous performance report),
> > kernel test robot noticed "BUG:kernel_NULL_pointer_dereference,address" on:
> >
> > commit: 2227a957e1d5b1941be4e4207879ec74f4bb37f8 ("sched/eevdf: Sort the rbtree by virtual deadline")
> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> >
> > [test failed on linus/master 3a5879d495b226d0404098e3564462d5f1daa33b]
> > [test failed on linux-next/master 01af33cc9894b4489fb68fa35c40e9fe85df63dc]
> >
> > in testcase: trinity
> > version: trinity-i386-abe9de86-1_20230429
> > with following parameters:
> >
> > runtime: 300s
> > group: group-03
> > nr_groups: 5
> >
> > test-description: Trinity is a linux system call fuzz tester.
> > test-url: http://codemonkey.org.uk/projects/trinity/
> >
> >
> > compiler: clang-17
> > test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
> >
> > (please refer to attached dmesg/kmsg for entire log/backtrace)
> >
> >
> >
> > we found this issue happens in very random way (23 out of 999 runs).
> > but keeps clean on parent.
>
> Thanks for reporting, I will try to reproduce the issue. Does the 'parent'
> mean the same code branch without this commit?

it just means the parent in git log.

xsang@inn:/c/repo/linux$ git log --oneline --graph 2227a957e1
* 2227a957e1d5b sched/eevdf: Sort the rbtree by virtual deadline
* 84db47ca7146d sched/numa: Fix mm numa_scan_seq based unconditional scan <-- parent

>
> >
> > 84db47ca7146d7bd 2227a957e1d5b1941be4e420787
> > ---------------- ---------------------------
> > fail:runs %reproduction fail:runs
> > | | |
> > :999 2% 23:999 dmesg.BUG:kernel_NULL_pointer_dereference,address
> > :999 2% 23:999 dmesg.Kernel_panic-not_syncing:Fatal_exception
> > :999 2% 23:999 dmesg.Oops:#[##]
> >
> >
> >
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> > | Closes: https://lore.kernel.org/oe-lkp/202401301012.2ed95df0-oliver.sang@xxxxxxxxx
> >
> >
> > sorry for below parse failure which caused no real line numbers.
> > we will follow further. the orgial dmesg could be fetch from below link.
> >
> >
> > [ 512.079810][ T8305] BUG: kernel NULL pointer dereference, address: 0000002c
> > [ 512.080897][ T8305] #PF: supervisor read access in kernel mode
> > [ 512.081636][ T8305] #PF: error_code(0x0000) - not-present page
> > [ 512.082337][ T8305] *pde = 00000000
> > [ 512.082829][ T8305] Oops: 0000 [#1] PREEMPT SMP
> > [ 512.083407][ T8305] CPU: 1 PID: 8305 Comm: watchdog Tainted: G W N 6.7.0-rc1-00006-g2227a957e1d5 #1 819e6d1a8b887f5f97adb4aed77d98b15504c836
> > [ 512.084986][ T8305] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> > [ 512.086203][ T8305] EIP: set_next_entity (fair.c:?)
>
> There was actually a NULL-test in pick_eevdf() before this commit,
> but I removed it by intent as I found it impossible to be NULL after
> examining 'all' the cases.
>
> Also cc Tiwei who once proposed to add this check back.
> https://lore.kernel.org/all/20231208112100.18141-1-tiwei.btw@xxxxxxxxxxxx/
>
> Thanks,
> Abel
>
> > [ 512.086881][ T8305] Code: 89 d6 89 cf 85 d2 74 22 39 77 58 75 1d 89 f0 90 90 90 90 90 8b 48 70 39 41 58 75 0e c7 41 58 00 00 00 00 8b 40 6c 85 c0 75 ea <83> 7e 2c 00 74 28 3e 8d 74 26 00 89 f9 89 f2 e8 36 59 00 00 89 f9
> > All code
> > ========
> > 0: 89 d6 mov %edx,%esi
> > 2: 89 cf mov %ecx,%edi
> > 4: 85 d2 test %edx,%edx
> > 6: 74 22 je 0x2a
> > 8: 39 77 58 cmp %esi,0x58(%rdi)
> > b: 75 1d jne 0x2a
> > d: 89 f0 mov %esi,%eax
> > f: 90 nop
> > 10: 90 nop
> > 11: 90 nop
> > 12: 90 nop
> > 13: 90 nop
> > 14: 8b 48 70 mov 0x70(%rax),%ecx
> > 17: 39 41 58 cmp %eax,0x58(%rcx)
> > 1a: 75 0e jne 0x2a
> > 1c: c7 41 58 00 00 00 00 movl $0x0,0x58(%rcx)
> > 23: 8b 40 6c mov 0x6c(%rax),%eax
> > 26: 85 c0 test %eax,%eax
> > 28: 75 ea jne 0x14
> > 2a:* 83 7e 2c 00 cmpl $0x0,0x2c(%rsi) <-- trapping instruction
> > 2e: 74 28 je 0x58
> > 30: 3e 8d 74 26 00 lea %ds:0x0(%rsi,%riz,1),%esi
> > 35: 89 f9 mov %edi,%ecx
> > 37: 89 f2 mov %esi,%edx
> > 39: e8 36 59 00 00 callq 0x5974
> > 3e: 89 f9 mov %edi,%ecx
> >
> > Code starting with the faulting instruction
> > ===========================================
> > 0: 83 7e 2c 00 cmpl $0x0,0x2c(%rsi)
> > 4: 74 28 je 0x2e
> > 6: 3e 8d 74 26 00 lea %ds:0x0(%rsi,%riz,1),%esi
> > b: 89 f9 mov %edi,%ecx
> > d: 89 f2 mov %esi,%edx
> > f: e8 36 59 00 00 callq 0x594a
> > 14: 89 f9 mov %edi,%ecx
> > [ 512.089261][ T8305] EAX: 00000000 EBX: e75ff100 ECX: e75ff100 EDX: 00000000
> > [ 512.090180][ T8305] ESI: 00000000 EDI: e75ff100 EBP: ed229dd0 ESP: ed229dc0
> > [ 512.091097][ T8305] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010046
> > [ 512.092138][ T8305] CR0: 80050033 CR2: 0000002c CR3: 0a508000 CR4: 000406d0
> > [ 512.093076][ T8305] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
> > [ 512.094004][ T8305] DR6: fffe0ff0 DR7: 00000400
> > [ 512.094643][ T8305] Call Trace:
> > [ 512.095145][ T8305] ? __die_body (dumpstack.c:?)
> > [ 512.095755][ T8305] ? __die (??:?)
> > [ 512.096309][ T8305] ? page_fault_oops (fault.c:?)
> > [ 512.096994][ T8305] ? __lock_acquire (lockdep.c:?)
> > [ 512.097677][ T8305] ? kmemleak_alloc (??:?)
> > [ 512.098343][ T8305] ? kernelmode_fixup_or_oops (fault.c:?)
> > [ 512.099085][ T8305] ? __bad_area_nosemaphore (fault.c:?)
> > [ 512.099839][ T8305] ? bad_area_nosemaphore (fault.c:?)
> > [ 512.100579][ T8305] ? do_user_addr_fault (fault.c:?)
> > [ 512.101325][ T8305] ? exc_page_fault (??:?)
> > [ 512.101992][ T8305] ? pvclock_clocksource_read_nowd (??:?)
> > [ 512.102799][ T8305] ? handle_exception (init_task.c:?)
> > [ 512.103492][ T8305] ? yield_to_task_fair (fair.c:?)
> > [ 512.104166][ T8305] ? pvclock_clocksource_read_nowd (??:?)
> > [ 512.104975][ T8305] ? set_next_entity (fair.c:?)
> > [ 512.105655][ T8305] ? pvclock_clocksource_read_nowd (??:?)
> > [ 512.106447][ T8305] ? set_next_entity (fair.c:?)
> > [ 512.107106][ T8305] pick_next_task_fair (??:?)
> > [ 512.107788][ T8305] ? put_prev_task_rt (build_policy.c:?)
> > [ 512.108460][ T8305] __pick_next_task_fair (fair.c:?)
> > [ 512.109162][ T8305] __schedule (core.c:?)
> > [ 512.109753][ T8305] schedule (??:?)
> > [ 512.110284][ T8305] do_nanosleep (hrtimer.c:?)
> > [ 512.110900][ T8305] hrtimer_nanosleep (??:?)
> > [ 512.111581][ T8305] ? __remove_hrtimer (hrtimer.c:?)
> > [ 512.112264][ T8305] common_nsleep (posix-timers.c:?)
> > [ 512.112891][ T8305] __ia32_sys_clock_nanosleep (??:?)
> > [ 512.113657][ T8305] ? syscall_enter_from_user_mode_work (??:?)
> > [ 512.114486][ T8305] __do_fast_syscall_32 (common.c:?)
> > [ 512.115180][ T8305] ? irqentry_exit_to_user_mode (??:?)
> > [ 512.115936][ T8305] ? irqentry_exit_to_user_mode (??:?)
> > [ 512.116690][ T8305] do_fast_syscall_32 (??:?)
> > [ 512.117386][ T8305] do_SYSENTER_32 (??:?)
> > [ 512.118022][ T8305] entry_SYSENTER_32 (??:?)
> > [ 512.118645][ T8305] EIP: 0xb7edf539
> > [ 512.119172][ T8305] Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 0f 1f 00 58 b8 77 00 00 00 cd 80 90 0f 1f
> > All code
> > ========
> > 0: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
> > 4: 10 07 adc %al,(%rdi)
> > 6: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
> > a: 10 08 adc %cl,(%rax)
> > c: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
> > ...
> > 20: 00 51 52 add %dl,0x52(%rcx)
> > 23: 55 push %rbp
> > 24:* 89 e5 mov %esp,%ebp <-- trapping instruction
> > 26: 0f 34 sysenter
> > 28: cd 80 int $0x80
> > 2a: 5d pop %rbp
> > 2b: 5a pop %rdx
> > 2c: 59 pop %rcx
> > 2d: c3 retq
> > 2e: 90 nop
> > 2f: 90 nop
> > 30: 90 nop
> > 31: 90 nop
> > 32: 0f 1f 00 nopl (%rax)
> > 35: 58 pop %rax
> > 36: b8 77 00 00 00 mov $0x77,%eax
> > 3b: cd 80 int $0x80
> > 3d: 90 nop
> > 3e: 0f .byte 0xf
> > 3f: 1f (bad)
> >
> > Code starting with the faulting instruction
> > ===========================================
> > 0: 5d pop %rbp
> > 1: 5a pop %rdx
> > 2: 59 pop %rcx
> > 3: c3 retq
> > 4: 90 nop
> > 5: 90 nop
> > 6: 90 nop
> > 7: 90 nop
> > 8: 0f 1f 00 nopl (%rax)
> > b: 58 pop %rax
> > c: b8 77 00 00 00 mov $0x77,%eax
> > 11: cd 80 int $0x80
> > 13: 90 nop
> > 14: 0f .byte 0xf
> > 15: 1f (bad)
> >
> >
> > The kernel config and materials to reproduce are available at:
> > https://download.01.org/0day-ci/archive/20240130/202401301012.2ed95df0-oliver.sang@xxxxxxxxx
> >
> >
> >

Next message: Miquel Raynal: "Re: [PATCH v1 14/18] thermal/drivers/armada: Migrate to thermal_zone_device_register()"
Previous message: Geert Uytterhoeven: "Re: [PATCH] spi: sh-msiof: avoid integer overflow in constants"
In reply to: Abel Wu: "Re: [linus:master] [sched/eevdf] 2227a957e1: BUG:kernel_NULL_pointer_dereference,address"
Next in thread: Abel Wu: "Re: Re: [linus:master] [sched/eevdf] 2227a957e1: BUG:kernel_NULL_pointer_dereference,address"
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