syzbot


BUG: unable to handle kernel paging request in seq_open

Status: auto-closed as invalid on 2022/01/05 02:54
Subsystems: kernfs
[Documentation on labels]
Reported-by: syzbot+f6a2ae421dfc09a54bd7@syzkaller.appspotmail.com
First crash: 903d, last: 903d

Sample crash report:
BUG: unable to handle page fault for address: 0000000700070770
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 2955 Comm: systemd-journal Not tainted 5.15.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:freelist_dereference mm/slub.c:345 [inline]
RIP: 0010:get_freepointer mm/slub.c:352 [inline]
RIP: 0010:get_freepointer_safe mm/slub.c:366 [inline]
RIP: 0010:slab_alloc_node mm/slub.c:3174 [inline]
RIP: 0010:slab_alloc mm/slub.c:3214 [inline]
RIP: 0010:kmem_cache_alloc+0xf1/0x390 mm/slub.c:3219
Code: 48 8b 51 08 48 8b 01 48 83 79 10 00 48 89 04 24 0f 84 75 02 00 00 48 85 c0 0f 84 6c 02 00 00 48 8b 7d 00 8b 4d 28 40 f6 c7 0f <48> 8b 1c 08 0f 85 76 02 00 00 48 8d 4a 08 65 48 0f c7 0f 0f 94 c0
RSP: 0018:ffffc9000205f970 EFLAGS: 00010246
RAX: 0000000700070700 RBX: 00000000000000e8 RCX: 0000000000000070
RDX: 000000000003bb70 RSI: 00000000000000e8 RDI: 0000000000038cb0
RBP: ffff888011ea4140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff81d2a807 R14: 0000000000000dc0 R15: 0000000000000dc0
FS:  00007efdc569d8c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000700070770 CR3: 000000001ad26000 CR4: 00000000003526f0
Call Trace:
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 seq_open+0x57/0x180 fs/seq_file.c:63
 kernfs_fop_open+0x5bf/0xd40 fs/kernfs/file.c:684
 do_dentry_open+0x4c8/0x11d0 fs/open.c:822
 do_open fs/namei.c:3428 [inline]
 path_openat+0x1c9a/0x2740 fs/namei.c:3561
 do_filp_open+0x1aa/0x400 fs/namei.c:3588
 do_sys_openat2+0x16d/0x4d0 fs/open.c:1200
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_open fs/open.c:1224 [inline]
 __se_sys_open fs/open.c:1220 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1220
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7efdc49586f0
Code: 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 83 3d 19 30 2c 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 fe 9d 01 00 48 89 04 24
RSP: 002b:00007ffd946c7308 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 000055d715e07c00 RCX: 00007efdc49586f0
RDX: 00000000000001b6 RSI: 0000000000080000 RDI: 00007ffd946c73e0
RBP: 0000000000000008 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000080000 R11: 0000000000000246 R12: 00007efdc53a07b4
R13: 0000000000000001 R14: 000000000000000f R15: 00007ffd946c73e0
Modules linked in:
CR2: 0000000700070770
---[ end trace e44afe9a223c309d ]---
RIP: 0010:freelist_dereference mm/slub.c:345 [inline]
RIP: 0010:get_freepointer mm/slub.c:352 [inline]
RIP: 0010:get_freepointer_safe mm/slub.c:366 [inline]
RIP: 0010:slab_alloc_node mm/slub.c:3174 [inline]
RIP: 0010:slab_alloc mm/slub.c:3214 [inline]
RIP: 0010:kmem_cache_alloc+0xf1/0x390 mm/slub.c:3219
Code: 48 8b 51 08 48 8b 01 48 83 79 10 00 48 89 04 24 0f 84 75 02 00 00 48 85 c0 0f 84 6c 02 00 00 48 8b 7d 00 8b 4d 28 40 f6 c7 0f <48> 8b 1c 08 0f 85 76 02 00 00 48 8d 4a 08 65 48 0f c7 0f 0f 94 c0
RSP: 0018:ffffc9000205f970 EFLAGS: 00010246
RAX: 0000000700070700 RBX: 00000000000000e8 RCX: 0000000000000070
RDX: 000000000003bb70 RSI: 00000000000000e8 RDI: 0000000000038cb0
RBP: ffff888011ea4140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff81d2a807 R14: 0000000000000dc0 R15: 0000000000000dc0
FS:  00007efdc569d8c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000700070770 CR3: 000000001ad26000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	48 8b 51 08          	mov    0x8(%rcx),%rdx
   4:	48 8b 01             	mov    (%rcx),%rax
   7:	48 83 79 10 00       	cmpq   $0x0,0x10(%rcx)
   c:	48 89 04 24          	mov    %rax,(%rsp)
  10:	0f 84 75 02 00 00    	je     0x28b
  16:	48 85 c0             	test   %rax,%rax
  19:	0f 84 6c 02 00 00    	je     0x28b
  1f:	48 8b 7d 00          	mov    0x0(%rbp),%rdi
  23:	8b 4d 28             	mov    0x28(%rbp),%ecx
  26:	40 f6 c7 0f          	test   $0xf,%dil
* 2a:	48 8b 1c 08          	mov    (%rax,%rcx,1),%rbx <-- trapping instruction
  2e:	0f 85 76 02 00 00    	jne    0x2aa
  34:	48 8d 4a 08          	lea    0x8(%rdx),%rcx
  38:	65 48 0f c7 0f       	cmpxchg16b %gs:(%rdi)
  3d:	0f 94 c0             	sete   %al

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/10/07 02:53 upstream 5af4055fa813 62ee0987 .config console log report info ci-upstream-kasan-gce BUG: unable to handle kernel paging request in seq_open
* Struck through repros no longer work on HEAD.