syzbot


general protection fault in khugepaged

Status: premoderation: reported on 2025/01/23 17:17
Reported-by: syzbot+9c15ac38af9f7c14d74e@syzkaller.appspotmail.com
First crash: 31d, last: 31d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in khugepaged mm C done 3 1678d 1690d 15/28 fixed on 2020/09/16 22:51
upstream general protection fault in khugepaged (2) mm 1 453d 449d 0/28 auto-obsoleted due to no activity on 2024/01/27 04:37
linux-4.19 general protection fault in khugepaged 1 1196d 1196d 0/1 auto-closed as invalid on 2022/03/15 05:26
upstream general protection fault in khugepaged (3) mm 13 117d 225d 0/28 auto-obsoleted due to no activity on 2025/02/06 22:32

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000084: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000420-0x0000000000000427]
CPU: 1 PID: 33 Comm: khugepaged Not tainted 6.1.118-syzkaller-00023-g092a580916f8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:khugepaged_scan_mm_slot mm/khugepaged.c:2336 [inline]
RIP: 0010:khugepaged_do_scan mm/khugepaged.c:2477 [inline]
RIP: 0010:khugepaged+0x498/0x1770 mm/khugepaged.c:2533
Code: 84 c0 0f 85 86 07 00 00 8b 1b 31 ff 89 de e8 af 97 b5 ff 85 db 0f 84 56 0a 00 00 48 8b 0c 24 48 8d 79 20 48 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 09 e8 dc 09 fd ff 48 8b 0c 24 48 8b 71 20 48 89
RSP: 0018:ffffc9000022fc40 EFLAGS: 00010207
RAX: 0000000000000084 RBX: 0000000000000001 RCX: 0000000000000406
RDX: ffff888100866540 RSI: 0000000000000001 RDI: 0000000000000426
RBP: ffffc9000022fef8 R08: ffffffff81bff241 R09: ffffed10264e65ab
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc9000022fe30
R13: 0000000000000006 R14: dffffc0000000000 R15: 0000000000000610
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e21eff8 CR3: 0000000114d0e000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kthread+0x26d/0x300 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:khugepaged_scan_mm_slot mm/khugepaged.c:2336 [inline]
RIP: 0010:khugepaged_do_scan mm/khugepaged.c:2477 [inline]
RIP: 0010:khugepaged+0x498/0x1770 mm/khugepaged.c:2533
Code: 84 c0 0f 85 86 07 00 00 8b 1b 31 ff 89 de e8 af 97 b5 ff 85 db 0f 84 56 0a 00 00 48 8b 0c 24 48 8d 79 20 48 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 09 e8 dc 09 fd ff 48 8b 0c 24 48 8b 71 20 48 89
RSP: 0018:ffffc9000022fc40 EFLAGS: 00010207
RAX: 0000000000000084 RBX: 0000000000000001 RCX: 0000000000000406
RDX: ffff888100866540 RSI: 0000000000000001 RDI: 0000000000000426
RBP: ffffc9000022fef8 R08: ffffffff81bff241 R09: ffffed10264e65ab
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc9000022fe30
R13: 0000000000000006 R14: dffffc0000000000 R15: 0000000000000610
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 000000010ebef000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	84 c0                	test   %al,%al
   2:	0f 85 86 07 00 00    	jne    0x78e
   8:	8b 1b                	mov    (%rbx),%ebx
   a:	31 ff                	xor    %edi,%edi
   c:	89 de                	mov    %ebx,%esi
   e:	e8 af 97 b5 ff       	call   0xffb597c2
  13:	85 db                	test   %ebx,%ebx
  15:	0f 84 56 0a 00 00    	je     0xa71
  1b:	48 8b 0c 24          	mov    (%rsp),%rcx
  1f:	48 8d 79 20          	lea    0x20(%rcx),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 30 00       	cmpb   $0x0,(%rax,%r14,1) <-- trapping instruction
  2f:	74 09                	je     0x3a
  31:	e8 dc 09 fd ff       	call   0xfffd0a12
  36:	48 8b 0c 24          	mov    (%rsp),%rcx
  3a:	48 8b 71 20          	mov    0x20(%rcx),%rsi
  3e:	48                   	rex.W
  3f:	89                   	.byte 0x89

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/23 17:16 android14-6.1 092a580916f8 a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in khugepaged
* Struck through repros no longer work on HEAD.