* Re: [Bug 209719] New: NULL pointer dereference
[not found] <bug-209719-27@https.bugzilla.kernel.org/>
@ 2020-10-16 20:33 ` Andrew Morton
2020-10-17 22:23 ` My Name
2020-10-18 7:28 ` Christoph Hellwig
0 siblings, 2 replies; 4+ messages in thread
From: Andrew Morton @ 2020-10-16 20:33 UTC (permalink / raw)
To: Ian Kent, Al Viro, Christoph Hellwig
Cc: bugzilla-daemon, linux-mm, linux-fsdevel, haxk612
(switched to email. Please respond via emailed reply-to-all, not via the
bugzilla web interface).
On Fri, 16 Oct 2020 14:59:08 +0000 bugzilla-daemon@bugzilla.kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=209719
>
> Bug ID: 209719
> Summary: NULL pointer dereference
> Product: Memory Management
> Version: 2.5
> Kernel Version: 5.9-next
> Hardware: All
> OS: Linux
> Tree: Mainline
> Status: NEW
> Severity: blocking
> Priority: P1
> Component: Other
> Assignee: akpm@linux-foundation.org
> Reporter: haxk612@gmail.com
> Regression: No
>
> Created attachment 293041
> --> https://bugzilla.kernel.org/attachment.cgi?id=293041&action=edit
> Kernel oops from journalctl
>
> Im sorry i didnt know to which table i should report this bug. So if i reported
> it to incorrect product and component then im sorry.
>
> System: Acer Nitro 5 AN515-42
> Kernel: 5.9-next-20201015
>
> I updated to newest tag on linux-next and system crashed at boot.
> Previously it only showed systemD message and then hidden it which i suspect is
> AMDGPU bug. I guess this bug is happening even before that one or the AMDGPU
> bug was fixed in linux-next.
Thanks for the report.
Probably autofs is interacting poorly with the __kernel_write() changes
in Christoph's 4d03e3cc59828 ("fs: don't allow kernel reads and writes
without iter ops"). I pasted the relevant oops trace. Could folks
please take a look?
Oct 16 16:38:53 TimeMachine kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000
Oct 16 16:38:53 TimeMachine kernel: #PF: supervisor read access in kernel mode
Oct 16 16:38:53 TimeMachine kernel: #PF: error_code(0x0000) - not-present page
Oct 16 16:38:53 TimeMachine kernel: PGD 0 P4D 0
Oct 16 16:38:53 TimeMachine kernel: Oops: 0000 [#1] PREEMPT SMP NOPTI
Oct 16 16:38:53 TimeMachine kernel: CPU: 1 PID: 319 Comm: systemd-binfmt Not tainted 5.9.0-next-20201015-1-next-git #1
Oct 16 16:38:53 TimeMachine kernel: Hardware name: Acer Nitro AN515-42/Freed_RRS, BIOS V1.13 02/11/2019
Oct 16 16:38:53 TimeMachine kernel: RIP: 0010:__kernel_write+0x11b/0x2c0
Oct 16 16:38:53 TimeMachine kernel: Code: 8b 54 24 20 0f b6 92 8f 00 00 00 65 48 8b 0c 25 c0 7b 01 00 48 8b b1 48 08 00 00 31 c9 48 85 f6 74 04 0f b7 4e 14 89 44 24 58 <48> 8b 03 be 01 00 00 00 48 8d 7c 24 10 66 89 54 24 5c 48 89 e2 66
Oct 16 16:38:53 TimeMachine kernel: RSP: 0018:ffff9c04c0e6f880 EFLAGS: 00010286
Oct 16 16:38:53 TimeMachine kernel: RAX: 0000000000020000 RBX: 0000000000000000 RCX: 0000000000000000
Oct 16 16:38:53 TimeMachine kernel: RDX: 0000000000000000 RSI: ffff928701167a28 RDI: ffff9c04c0e6f8e8
Oct 16 16:38:53 TimeMachine kernel: RBP: ffff9287046a7d00 R08: 0000000000000130 R09: 00000010af978cf7
Oct 16 16:38:53 TimeMachine kernel: R10: 000000000000000f R11: ffff928708ce9110 R12: ffff9287046a7d00
Oct 16 16:38:53 TimeMachine kernel: R13: ffff9c04c0e6f8b8 R14: ffff928709f6d868 R15: 0000000000000130
Oct 16 16:38:53 TimeMachine kernel: FS: 00007fb657195000(0000) GS:ffff928a3fc40000(0000) knlGS:0000000000000000
Oct 16 16:38:53 TimeMachine kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 16 16:38:53 TimeMachine kernel: CR2: 0000000000000000 CR3: 0000000102f8e000 CR4: 00000000003506e0
Oct 16 16:38:53 TimeMachine kernel: Call Trace:
Oct 16 16:38:53 TimeMachine kernel: autofs_notify_daemon+0x13f/0x2b0
Oct 16 16:38:53 TimeMachine kernel: ? cpumask_next_and+0x19/0x20
Oct 16 16:38:53 TimeMachine kernel: autofs_wait+0x606/0x7e0
Oct 16 16:38:53 TimeMachine kernel: ? chacha_block_generic+0x6f/0xb0
Oct 16 16:38:53 TimeMachine kernel: ? autofs_mount_wait+0x49/0xf0
Oct 16 16:38:53 TimeMachine kernel: ? _raw_spin_unlock+0x16/0x30
Oct 16 16:38:53 TimeMachine kernel: autofs_mount_wait+0x49/0xf0
Oct 16 16:38:53 TimeMachine kernel: autofs_d_automount+0xd9/0x1f0
Oct 16 16:38:53 TimeMachine kernel: __traverse_mounts+0x8f/0x220
Oct 16 16:38:53 TimeMachine kernel: step_into+0x3d6/0x700
Oct 16 16:38:53 TimeMachine kernel: walk_component+0x83/0x1b0
Oct 16 16:38:53 TimeMachine kernel: ? _raw_spin_unlock+0x16/0x30
Oct 16 16:38:53 TimeMachine kernel: link_path_walk+0x25d/0x390
Oct 16 16:38:53 TimeMachine kernel: path_openat+0x8d/0x10b0
Oct 16 16:38:53 TimeMachine kernel: ? _raw_read_unlock+0x18/0x30
Oct 16 16:38:53 TimeMachine kernel: ? kmem_cache_free+0x116/0x450
Oct 16 16:38:53 TimeMachine kernel: do_filp_open+0x9c/0x140
Oct 16 16:38:53 TimeMachine kernel: do_sys_openat2+0xb1/0x160
Oct 16 16:38:53 TimeMachine kernel: __x64_sys_openat+0x54/0x90
Oct 16 16:38:53 TimeMachine kernel: do_syscall_64+0x33/0x40
Oct 16 16:38:53 TimeMachine kernel: entry_SYSCALL_64_after_hwframe+0x44/0xa9
Oct 16 16:38:53 TimeMachine kernel: RIP: 0033:0x7fb657f85c1b
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