(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@xxxxxxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxxxxxxx > Reporter: haxk612@xxxxxxxxx > 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
