I just got the following on linux-next from March 25th. You dealt last with
include/linux/percpu-rwsem.h, so you may have an idea where to look for the
root cause.
Mar 26 23:29:51 zotac kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000
Mar 26 23:29:51 zotac kernel: #PF: supervisor read access in kernel mode
Mar 26 23:29:51 zotac kernel: #PF: error_code(0x0000) - not-present page
Mar 26 23:29:51 zotac kernel: PGD 0 P4D 0
Mar 26 23:29:51 zotac kernel: Oops: 0000 [#1] SMP
Mar 26 23:29:51 zotac kernel: CPU: 2 PID: 2404 Comm: resolvconf Not tainted 5.6.0-rc7-next-20200325+ #1
Mar 26 23:29:51 zotac kernel: Hardware name: NA ZBOX-CI327NANO-GS-01/ZBOX-CI327NANO-GS-01, BIOS 5.12 04/26/2018
Mar 26 23:29:51 zotac kernel: RIP: 0010:link_path_walk.part.0+0x1c5/0x350
Mar 26 23:29:51 zotac kernel: Code: 41 83 ef 01 31 f6 4c 89 f7 49 63 c7 48 8d 04 40 48 c1 e0 04 49 03 46 58 4c 8b 68 20 e8 84 fc ff ff 48 85 c0 75 5f 49 8b 46 08 <8b> 00 25 00 00 70 00 3d 00 00 20 00 0f 84 a5 fe ff ff 41 f6 46 38
Mar 26 23:29:51 zotac kernel: RSP: 0018:ffffb272403c7ba8 EFLAGS: 00010246
Mar 26 23:29:51 zotac kernel: RAX: 0000000000000000 RBX: fefefefefefefeff RCX: 0000000000000000
Mar 26 23:29:51 zotac kernel: RDX: ffff9f21bab88000 RSI: ffffffffbea46aa0 RDI: ffff9f21bab88858
Mar 26 23:29:51 zotac kernel: RBP: ffffb272403c7bf0 R08: 0000000000000001 R09: 0000000000000000
Mar 26 23:29:51 zotac kernel: R10: 80800000007fffff R11: 0000000000000000 R12: 2f2f2f2f2f2f2f2f
Mar 26 23:29:51 zotac kernel: R13: ffff9f21b9476243 R14: ffffb272403c7c30 R15: 0000000000000001
Mar 26 23:29:51 zotac kernel: FS: 00007f464ebc8b80(0000) GS:ffff9f21bbd00000(0000) knlGS:0000000000000000
Mar 26 23:29:51 zotac kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Mar 26 23:29:51 zotac kernel: CR2: 0000000000000000 CR3: 0000000178b7d000 CR4: 00000000003406e0
Mar 26 23:29:51 zotac kernel: Call Trace:
Mar 26 23:29:51 zotac kernel: path_lookupat.isra.0+0x3b/0x150
Mar 26 23:29:51 zotac kernel: filename_lookup+0xb4/0x140
Mar 26 23:29:51 zotac kernel: ? rcu_read_lock_sched_held+0x4a/0x80
Mar 26 23:29:51 zotac kernel: ? kmem_cache_alloc+0x24c/0x280
Mar 26 23:29:51 zotac kernel: kern_path+0x31/0x40
Mar 26 23:29:51 zotac kernel: unix_find_other+0x4f/0x2b0
Mar 26 23:29:51 zotac kernel: unix_stream_connect+0x115/0x6c4
Mar 26 23:29:51 zotac kernel: __sys_connect+0xec/0x110
Mar 26 23:29:51 zotac kernel: ? lockdep_hardirqs_on+0xf2/0x1a0
Mar 26 23:29:51 zotac kernel: __x64_sys_connect+0x19/0x20
Mar 26 23:29:51 zotac kernel: do_syscall_64+0x50/0x1e0
Mar 26 23:29:51 zotac kernel: entry_SYSCALL_64_after_hwframe+0x49/0xb3
Mar 26 23:29:51 zotac kernel: RIP: 0033:0x7f464ed3b447
Mar 26 23:29:51 zotac kernel: Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 18 89 54 24 0c 48 89 34 24 89
Mar 26 23:29:51 zotac kernel: RSP: 002b:00007ffd3daa5d88 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
Mar 26 23:29:51 zotac kernel: RAX: ffffffffffffffda RBX: 00007ffd3daa5d90 RCX: 00007f464ed3b447
Mar 26 23:29:51 zotac kernel: RDX: 000000000000006e RSI: 00007ffd3daa5de0 RDI: 0000000000000003
Mar 26 23:29:51 zotac kernel: RBP: 00007ffd3daa5e90 R08: 0000563ef84d0370 R09: 0000000000000400
Mar 26 23:29:51 zotac kernel: R10: 0000000000000410 R11: 0000000000000246 R12: 0000000000000013
Mar 26 23:29:51 zotac kernel: R13: 00007f464edc92a8 R14: 0000000000000003 R15: 0000000000000007
Mar 26 23:29:51 zotac kernel: Modules linked in: snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic vfat fat x86_pkg_temp_thermal coretemp aesni_intel glue_helper crypto_simd cryptd snd_hda_intel i915 snd_intel_dspcfg snd_hda_code>
Mar 26 23:29:51 zotac kernel: CR2: 0000000000000000
Mar 26 23:29:51 zotac kernel: ---[ end trace 5cf9f2658df059d3 ]---
Mar 26 23:29:51 zotac kernel: RIP: 0010:link_path_walk.part.0+0x1c5/0x350
Mar 26 23:29:51 zotac kernel: Code: 41 83 ef 01 31 f6 4c 89 f7 49 63 c7 48 8d 04 40 48 c1 e0 04 49 03 46 58 4c 8b 68 20 e8 84 fc ff ff 48 85 c0 75 5f 49 8b 46 08 <8b> 00 25 00 00 70 00 3d 00 00 20 00 0f 84 a5 fe ff ff 41 f6 46 38
Mar 26 23:29:51 zotac kernel: RSP: 0018:ffffb272403c7ba8 EFLAGS: 00010246
Mar 26 23:29:51 zotac kernel: RAX: 0000000000000000 RBX: fefefefefefefeff RCX: 0000000000000000
Mar 26 23:29:51 zotac kernel: RDX: ffff9f21bab88000 RSI: ffffffffbea46aa0 RDI: ffff9f21bab88858
Mar 26 23:29:51 zotac kernel: RBP: ffffb272403c7bf0 R08: 0000000000000001 R09: 0000000000000000
Mar 26 23:29:51 zotac kernel: R10: 80800000007fffff R11: 0000000000000000 R12: 2f2f2f2f2f2f2f2f
Mar 26 23:29:51 zotac kernel: R13: ffff9f21b9476243 R14: ffffb272403c7c30 R15: 0000000000000001
Mar 26 23:29:51 zotac kernel: FS: 00007f464ebc8b80(0000) GS:ffff9f21bbd00000(0000) knlGS:0000000000000000
Mar 26 23:29:51 zotac kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Mar 26 23:29:51 zotac kernel: CR2: 0000000000000000 CR3: 0000000178b7d000 CR4: 00000000003406e0
Mar 26 23:29:51 zotac kernel: BUG: sleeping function called from invalid context at include/linux/percpu-rwsem.h:49
Mar 26 23:29:51 zotac kernel: in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 2404, name: resolvconf
Mar 26 23:29:51 zotac kernel: INFO: lockdep is turned off.
Mar 26 23:29:51 zotac kernel: irq event stamp: 2606
Mar 26 23:29:51 zotac kernel: hardirqs last enabled at (2605): [<ffffffffbdc52a5d>] handle_dots.part.0+0x1ad/0x5f0
Mar 26 23:29:51 zotac kernel: hardirqs last disabled at (2606): [<ffffffffbda01e5d>] trace_hardirqs_off_thunk+0x1a/0x1c
Mar 26 23:29:51 zotac kernel: softirqs last enabled at (2598): [<ffffffffbe0c8c9b>] unix_create1+0x6b/0x210
Mar 26 23:29:51 zotac kernel: softirqs last disabled at (2596): [<ffffffffbe0c8c9b>] unix_create1+0x6b/0x210
Mar 26 23:29:51 zotac kernel: CPU: 2 PID: 2404 Comm: resolvconf Tainted: G D 5.6.0-rc7-next-20200325+ #1
Mar 26 23:29:51 zotac kernel: Hardware name: NA ZBOX-CI327NANO-GS-01/ZBOX-CI327NANO-GS-01, BIOS 5.12 04/26/2018
Mar 26 23:29:51 zotac kernel: Call Trace:
Mar 26 23:29:51 zotac kernel: dump_stack+0x7a/0xb0
Mar 26 23:29:51 zotac kernel: ___might_sleep.cold+0xa6/0xb7
Mar 26 23:29:51 zotac kernel: __might_sleep+0x46/0x80
Mar 26 23:29:51 zotac kernel: exit_signals+0x2f/0x300
Mar 26 23:29:51 zotac kernel: do_exit+0xa4/0xb00
Mar 26 23:29:51 zotac kernel: rewind_stack_do_exit+0x17/0x20
Mar 26 23:29:51 zotac kernel: RIP: 0033:0x7f464ed3b447
Mar 26 23:29:51 zotac kernel: Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 18 89 54 24 0c 48 89 34 24 89
Mar 26 23:29:51 zotac kernel: RSP: 002b:00007ffd3daa5d88 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
Mar 26 23:29:51 zotac kernel: RAX: ffffffffffffffda RBX: 00007ffd3daa5d90 RCX: 00007f464ed3b447
Mar 26 23:29:51 zotac kernel: RDX: 000000000000006e RSI: 00007ffd3daa5de0 RDI: 0000000000000003
Mar 26 23:29:51 zotac kernel: RBP: 00007ffd3daa5e90 R08: 0000563ef84d0370 R09: 0000000000000400
Mar 26 23:29:51 zotac kernel: R10: 0000000000000410 R11: 0000000000000246 R12: 0000000000000013
Mar 26 23:29:51 zotac kernel: R13: 00007f464edc92a8 R14: 0000000000000003 R15: 0000000000000007
On 27.03.2020 09:46, Hillf Danton wrote:
>
> On Fri, 27 Mar 2020 00:56:34 +0100 Heiner Kallweit wrote:
>>
>> I just got the following on linux-next from March 25th. You dealt last with
>> include/linux/percpu-rwsem.h, so you may have an idea where to look for the
>> root cause.
>>
>>
>> Mar 26 23:29:51 zotac kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000
>> Mar 26 23:29:51 zotac kernel: #PF: supervisor read access in kernel mode
>> Mar 26 23:29:51 zotac kernel: #PF: error_code(0x0000) - not-present page
>> Mar 26 23:29:51 zotac kernel: PGD 0 P4D 0
>> Mar 26 23:29:51 zotac kernel: Oops: 0000 [#1] SMP
>> Mar 26 23:29:51 zotac kernel: CPU: 2 PID: 2404 Comm: resolvconf Not tainted 5.6.0-rc7-next-20200325+ #1
>> Mar 26 23:29:51 zotac kernel: Hardware name: NA ZBOX-CI327NANO-GS-01/ZBOX-CI327NANO-GS-01, BIOS 5.12 04/26/2018
>> Mar 26 23:29:51 zotac kernel: RIP: 0010:link_path_walk.part.0+0x1c5/0x350
>> Mar 26 23:29:51 zotac kernel: Code: 41 83 ef 01 31 f6 4c 89 f7 49 63 c7 48 8d 04 40 48 c1 e0 04 49 03 46 58 4c 8b 68 20 e8 84 fc ff ff 48 85 c0 75 5f 49 8b 46 08 <8b> 00 25 00 00 70 00 3d 00 00 20 00 0f 84 a5 fe ff ff 41 f6 46 38
>> Mar 26 23:29:51 zotac kernel: RSP: 0018:ffffb272403c7ba8 EFLAGS: 00010246
>> Mar 26 23:29:51 zotac kernel: RAX: 0000000000000000 RBX: fefefefefefefeff RCX: 0000000000000000
>> Mar 26 23:29:51 zotac kernel: RDX: ffff9f21bab88000 RSI: ffffffffbea46aa0 RDI: ffff9f21bab88858
>> Mar 26 23:29:51 zotac kernel: RBP: ffffb272403c7bf0 R08: 0000000000000001 R09: 0000000000000000
>> Mar 26 23:29:51 zotac kernel: R10: 80800000007fffff R11: 0000000000000000 R12: 2f2f2f2f2f2f2f2f
>> Mar 26 23:29:51 zotac kernel: R13: ffff9f21b9476243 R14: ffffb272403c7c30 R15: 0000000000000001
>> Mar 26 23:29:51 zotac kernel: FS: 00007f464ebc8b80(0000) GS:ffff9f21bbd00000(0000) knlGS:0000000000000000
>> Mar 26 23:29:51 zotac kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> Mar 26 23:29:51 zotac kernel: CR2: 0000000000000000 CR3: 0000000178b7d000 CR4: 00000000003406e0
>> Mar 26 23:29:51 zotac kernel: Call Trace:
>> Mar 26 23:29:51 zotac kernel: path_lookupat.isra.0+0x3b/0x150
>> Mar 26 23:29:51 zotac kernel: filename_lookup+0xb4/0x140
>> Mar 26 23:29:51 zotac kernel: ? rcu_read_lock_sched_held+0x4a/0x80
>> Mar 26 23:29:51 zotac kernel: ? kmem_cache_alloc+0x24c/0x280
>> Mar 26 23:29:51 zotac kernel: kern_path+0x31/0x40
>> Mar 26 23:29:51 zotac kernel: unix_find_other+0x4f/0x2b0
>> Mar 26 23:29:51 zotac kernel: unix_stream_connect+0x115/0x6c4
>> Mar 26 23:29:51 zotac kernel: __sys_connect+0xec/0x110
>> Mar 26 23:29:51 zotac kernel: ? lockdep_hardirqs_on+0xf2/0x1a0
>> Mar 26 23:29:51 zotac kernel: __x64_sys_connect+0x19/0x20
>> Mar 26 23:29:51 zotac kernel: do_syscall_64+0x50/0x1e0
>> Mar 26 23:29:51 zotac kernel: entry_SYSCALL_64_after_hwframe+0x49/0xb3
>
> FYI: another null-ptr-deref was reported at
>
> https://lore.kernel.org/lkml/[email protected]/
>
> and fix in that thread.
>
Thanks for the quick feedback and the hint!
Heiner