general protection fault in percpu_ref_kill_and_confirm

Status: upstream: reported on 2026/09/04 03:34
Reported-by: syzbot+a36fa652db7dd1129c1e@syzkaller.appspotmail.com
First crash: 70d, last: 7h00m
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 BUG: unable to handle kernel paging request in percpu_ref_kill_and_confirm 8 11 37d 71d 0/3 upstream: reported on 2026/09/03 15:38

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 22074 Comm: syz.2.3441 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
RIP: 0010:percpu_ref_kill_and_confirm+0xf1/0x130 lib/percpu-refcount.c:392
Code: 01 4c 8d 63 08 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 5e 76 b2 fd 4d 8b 24 24 49 83 c4 08 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 40 76 b2 fd 49 8b 14 24 48 c7 c7
RSP: 0018:ffffc9000d287a08 EFLAGS: 00010002
RAX: 0000000000000001 RBX: ffff88807b9d80d0 RCX: 0000000000080000
RDX: ffffc9000dbeb000 RSI: 0000000000002e9e RDI: 0000000000002e9f
RBP: 1ffff1100f73b01a R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001a50f1c R12: 0000000000000008
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000a02
FS:  00007f2ce1f416c0(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e91eff8 CR3: 000000007e284000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000008 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 percpu_ref_kill include/linux/percpu-refcount.h:149 [inline]
 __mddev_suspend+0x2d1/0x630 drivers/md/md.c:533
 mddev_suspend_and_lock drivers/md/md.h:876 [inline]
 raid_disks_store+0xb8/0x550 drivers/md/md.c:4320
 md_attr_store+0x19c/0x390 drivers/md/md.c:5756
 kernfs_fop_write_iter+0x3a4/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2019 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2ce0fa94d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2ce1f41028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2ce1225fa0 RCX: 00007f2ce0fa94d9
RDX: 0000000000000001 RSI: 0000200000000180 RDI: 0000000000000005
RBP: 00007f2ce103804e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2ce1226038 R14: 00007f2ce1225fa0 R15: 00007ffcda6fcc18
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:percpu_ref_kill_and_confirm+0xf1/0x130 lib/percpu-refcount.c:392
Code: 01 4c 8d 63 08 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 5e 76 b2 fd 4d 8b 24 24 49 83 c4 08 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 e7 e8 40 76 b2 fd 49 8b 14 24 48 c7 c7
RSP: 0018:ffffc9000d287a08 EFLAGS: 00010002
RAX: 0000000000000001 RBX: ffff88807b9d80d0 RCX: 0000000000080000
RDX: ffffc9000dbeb000 RSI: 0000000000002e9e RDI: 0000000000002e9f
RBP: 1ffff1100f73b01a R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001a50f1c R12: 0000000000000008
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000a02
FS:  00007f2ce1f416c0(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e91eff8 CR3: 000000007e284000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000008 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	01 4c 8d 63          	add    %ecx,0x63(%rbp,%rcx,4)
   4:	08 4c 89 e0          	or     %cl,-0x20(%rcx,%rcx,4)
   8:	48 c1 e8 03          	shr    $0x3,%rax
   c:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  11:	74 08                	je     0x1b
  13:	4c 89 e7             	mov    %r12,%rdi
  16:	e8 5e 76 b2 fd       	call   0xfdb27679
  1b:	4d 8b 24 24          	mov    (%r12),%r12
  1f:	49 83 c4 08          	add    $0x8,%r12
  23:	4c 89 e0             	mov    %r12,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 e7             	mov    %r12,%rdi
  34:	e8 40 76 b2 fd       	call   0xfdb27679
  39:	49 8b 14 24          	mov    (%r12),%rdx
  3d:	48                   	rex.W
  3e:	c7                   	.byte 0xc7
  3f:	c7                   	.byte 0xc7

Crashes (20):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/13 10:30 linux-6.6.y 5139929c698c 26b2fee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/11/12 23:09 linux-6.6.y 5139929c698c c0087d7f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/11/05 10:54 linux-6.6.y b5a1dc3ad482 2ee8459f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/11/05 10:54 linux-6.6.y b5a1dc3ad482 2ee8459f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/11/04 19:48 linux-6.6.y b5a1dc3ad482 73438ed0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/11/03 22:29 linux-6.6.y b5a1dc3ad482 e2d35131 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/11/03 22:29 linux-6.6.y b5a1dc3ad482 e2d35131 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/11/01 14:07 linux-6.6.y b5a1dc3ad482 25a0ae84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/10/31 01:55 linux-6.6.y b5a1dc3ad482 0ec395f8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/10/30 09:17 linux-6.6.y 0aebf2870d53 b498adee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/10/26 06:07 linux-6.6.y 0aebf2870d53 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/10/25 18:22 linux-6.6.y 0aebf2870d53 1d9ca40b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/10/22 20:40 linux-6.6.y 0aebf2870d53 b55fad29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/09/12 06:02 linux-6.6.y 8b73de7da85f 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/09/10 04:55 linux-6.6.y 8b73de7da85f 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/09/09 09:05 linux-6.6.y 8b73de7da85f 8387c273 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/09/08 21:48 linux-6.6.y 8b73de7da85f 243b72f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/09/04 03:37 linux-6.6.y 8b73de7da85f 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/09/04 03:36 linux-6.6.y 8b73de7da85f 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
2026/09/04 03:33 linux-6.6.y 8b73de7da85f 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in percpu_ref_kill_and_confirm
* Struck through repros no longer work on HEAD.