syzbot


general protection fault in percpu_ref_get_many

Status: upstream: reported on 2025/07/29 15:11
Reported-by: syzbot+306276e9c5e7fee2c898@syzkaller.appspotmail.com
First crash: 30d, last: 30d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in percpu_ref_get_many mm cgroups 2 1 178d 178d 0/29 closed as invalid on 2025/03/30 10:14
upstream BUG: unable to handle kernel paging request in percpu_ref_get_many (2) mm cgroups 23 69 9h47m 96d 0/29 upstream: reported on 2025/05/25 00:43
upstream BUG: unable to handle kernel paging request in percpu_ref_get_many mm cgroups 8 3 966d 1037d 0/29 auto-obsoleted due to no activity on 2023/04/06 05:44

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc001fffc000: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x00000000fffe0000-0x00000000fffe0007]
CPU: 0 PID: 3562 Comm: udevd Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__ref_is_percpu include/linux/percpu-refcount.h:174 [inline]
RIP: 0010:percpu_ref_get_many+0x69/0x110 include/linux/percpu-refcount.h:204
Code: 01 48 c7 c7 00 d1 15 8a be e5 02 00 00 48 c7 c2 40 d1 15 8a e8 b8 4d dc 07 49 bf 00 00 00 00 00 fc ff df 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 68 ef fa ff 49 8b 06 a8 03 75 56
RSP: 0018:ffffc90002ddf540 EFLAGS: 00010206
RAX: 000000001fffc000 RBX: 0000000000000001 RCX: 0d18060440f2d800
RDX: 0000000000000000 RSI: ffffffff8a599320 RDI: ffffffff8a5992e0
RBP: ffffc90002ddf638 R08: dffffc0000000000 R09: fffffbfff1ff6e19
R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: ffff8880b9036460
R13: 1ffff11017206c8c R14: 00000000fffe0000 R15: dffffc0000000000
FS:  00007fbd90d85880(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc5cd1aff8 CR3: 000000007d9ac000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 percpu_ref_get include/linux/percpu-refcount.h:222 [inline]
 obj_cgroup_get include/linux/memcontrol.h:805 [inline]
 refill_obj_stock+0x12e/0x440 mm/memcontrol.c:3243
 memcg_slab_free_hook+0x157/0x1f0 mm/slab.h:364
 do_slab_free mm/slub.c:3432 [inline]
 ___cache_free+0x63/0x120 mm/slub.c:3506
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 __kmalloc+0x127/0x330 mm/slub.c:4403
 kmalloc include/linux/slab.h:609 [inline]
 tomoyo_realpath_from_path+0x118/0x610 security/tomoyo/realpath.c:254
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x1cd/0x510 security/tomoyo/file.c:822
 security_inode_getattr+0xcf/0x120 security/security.c:1348
 vfs_getattr+0x26/0x3a0 fs/stat.c:157
 vfs_fstat fs/stat.c:182 [inline]
 __do_sys_newfstat fs/stat.c:421 [inline]
 __se_sys_newfstat fs/stat.c:418 [inline]
 __x64_sys_newfstat+0x104/0x1d0 fs/stat.c:418
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fbd90eddad7
Code: 73 01 c3 48 8b 0d 21 f3 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 05 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffe962b3c68 EFLAGS: 00000202 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 000000000000000e RCX: 00007fbd90eddad7
RDX: 0000000000090800 RSI: 00007ffe962b3c70 RDI: 000000000000000e
RBP: 00007ffe962b3c70 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000202 R12: 00005560fe3ac7c0
R13: 00000000000000fe R14: 00005560c2212be0 R15: 00007ffe962b3fd0
 </TASK>
Modules linked in:
---[ end trace 95c1496334826c8e ]---
RIP: 0010:__ref_is_percpu include/linux/percpu-refcount.h:174 [inline]
RIP: 0010:percpu_ref_get_many+0x69/0x110 include/linux/percpu-refcount.h:204
Code: 01 48 c7 c7 00 d1 15 8a be e5 02 00 00 48 c7 c2 40 d1 15 8a e8 b8 4d dc 07 49 bf 00 00 00 00 00 fc ff df 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 68 ef fa ff 49 8b 06 a8 03 75 56
RSP: 0018:ffffc90002ddf540 EFLAGS: 00010206
RAX: 000000001fffc000 RBX: 0000000000000001 RCX: 0d18060440f2d800
RDX: 0000000000000000 RSI: ffffffff8a599320 RDI: ffffffff8a5992e0
RBP: ffffc90002ddf638 R08: dffffc0000000000 R09: fffffbfff1ff6e19
R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: ffff8880b9036460
R13: 1ffff11017206c8c R14: 00000000fffe0000 R15: dffffc0000000000
FS:  00007fbd90d85880(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc5cd1aff8 CR3: 000000007d9ac000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	01 48 c7             	add    %ecx,-0x39(%rax)
   3:	c7 00 d1 15 8a be    	movl   $0xbe8a15d1,(%rax)
   9:	e5 02                	in     $0x2,%eax
   b:	00 00                	add    %al,(%rax)
   d:	48 c7 c2 40 d1 15 8a 	mov    $0xffffffff8a15d140,%rdx
  14:	e8 b8 4d dc 07       	call   0x7dc4dd1
  19:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  20:	fc ff df
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 f7             	mov    %r14,%rdi
  34:	e8 68 ef fa ff       	call   0xfffaefa1
  39:	49 8b 06             	mov    (%r14),%rax
  3c:	a8 03                	test   $0x3,%al
  3e:	75 56                	jne    0x96

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/29 15:10 linux-5.15.y c79648372d02 c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan general protection fault in percpu_ref_get_many
* Struck through repros no longer work on HEAD.