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BUG: unable to handle kernel NULL pointer dereference in asm_exc_page_fault

Status: closed as invalid on 2024/09/06 13:56
Subsystems: kernel
[Documentation on labels]
First crash: 168d, last: 168d

Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 800000007ec72067 P4D 800000007ec72067 PUD 2819c067 PMD 0 
Thread overran stack, or stack corrupted
Oops: Oops: 0010 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5325 Comm: syz.1.7 Not tainted 6.11.0-rc5-next-20240827-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc900041a6d20 EFLAGS: 00010086
RAX: 0000000000000000 RBX: ffffc900041a7360 RCX: 0000000000040000
RDX: ffffc90009199000 RSI: 000000000002f826 RDI: 000000000002f827
RBP: ffffc900041a6de0 R08: ffffffff84b5002a R09: ffffffff81420825
R10: 0000000000000002 R11: ffffffff8bb167a0 R12: ffffffff8e4c6160
R13: 1ffff92000834da8 R14: dffffc0000000000 R15: ffffc900041a6d60
FS:  00007fbc403e86c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000001f4ec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:error_entry+0x6d/0x140 arch/x86/entry/entry_64.S:1021
Code: f6 84 24 90 00 00 00 03 74 4e 0f 01 f8 0f 1f 00 66 90 0f 20 d8 0f 1f 44 00 00 48 25 ff e7 ff ff 0f 22 d8 66 90 b9 48 00 00 00 <65> 48 8b 15 bb 60 22 74 89 d0 48 c1 ea 20 0f 30 90 0f 1f 44 00 00
RSP: 0000:ffffc900041a6dd0 EFLAGS: 00010006
RAX: 000000001f4ec000 RBX: 0000000000000000 RCX: 0000000000000048
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000007fffffff
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
RIP: 8ab3:vsnprintf+0xf2/0x1da0
RSP: 0000:ffffffff814254e0 EFLAGS: ffffffff8e06cbcf ORIG_RAX: 0000000000000000
RAX: 03ffff24001069c0 RBX: 0000000000000008 RCX: ffffc900041a7118
RDX: ffffc90009199000 RSI: 0000000000000008 RDI: 000000007fffffff
RBP: ffffffff8142558f R08: ffffffff8bb92a7d R09: 0000000000000000
R10: ffffc900041a7130 R11: fffff52000834e29 R12: 1ffff92000834e2f
R13: ffffffff815f8eea R14: ffffc900041a6f68 R15: dffffc0000000000
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	f6 84 24 90 00 00 00 	testb  $0x3,0x90(%rsp)
   7:	03
   8:	74 4e                	je     0x58
   a:	0f 01 f8             	swapgs
   d:	0f 1f 00             	nopl   (%rax)
  10:	66 90                	xchg   %ax,%ax
  12:	0f 20 d8             	mov    %cr3,%rax
  15:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  1a:	48 25 ff e7 ff ff    	and    $0xffffffffffffe7ff,%rax
  20:	0f 22 d8             	mov    %rax,%cr3
  23:	66 90                	xchg   %ax,%ax
  25:	b9 48 00 00 00       	mov    $0x48,%ecx
* 2a:	65 48 8b 15 bb 60 22 	mov    %gs:0x742260bb(%rip),%rdx        # 0x742260ed <-- trapping instruction
  31:	74
  32:	89 d0                	mov    %edx,%eax
  34:	48 c1 ea 20          	shr    $0x20,%rdx
  38:	0f 30                	wrmsr
  3a:	90                   	nop
  3b:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/28 07:08 linux-next 6f923748057a 6c853ff9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root BUG: unable to handle kernel NULL pointer dereference in asm_exc_page_fault
* Struck through repros no longer work on HEAD.