syzbot


KASAN: null-ptr-deref Write in backing_data_changed

Status: auto-obsoleted due to no activity on 2024/02/08 13:32
Reported-by: syzbot+1d95dc0218855a631aef@syzkaller.appspotmail.com
First crash: 190d, last: 117d
Fix bisection: fixed by (bisect log) :
commit 44714c920d036214a739510876525841ab6decf1
Author: liujinbao1 <liujinbao1@xiaomi.corp-partner.google.com>
Date: Thu Oct 12 04:28:06 2023 +0000

  ANDROID: fuse-bpf: Add NULL pointer check in fuse_entry_revalidate

  
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: null-ptr-deref Write in backing_data_changed origin:downstream C done 1 99d 162d 2/2 fixed on 2023/12/20 15:24
android-6-1 KASAN: null-ptr-deref Write in backing_data_changed origin:downstream C done done 1 152d 189d 0/2 auto-obsoleted due to no activity on 2024/01/04 12:03
Last patch testing requests (1)
Created Duration User Patch Repo Result
2023/09/03 07:33 6m retest repro android13-5.10-lts report log
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2023/12/01 02:52 2h08m bisect fix android13-5.10-lts job log (1)
2023/10/31 12:40 50m bisect fix android13-5.10-lts job log (0) log

Sample crash report:
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: null-ptr-deref in atomic_inc_return include/asm-generic/atomic-instrumented.h:250 [inline]
BUG: KASAN: null-ptr-deref in ihold+0x20/0x60 fs/inode.c:423
Write of size 4 at addr 0000000000000170 by task syz-executor796/290

CPU: 1 PID: 290 Comm: syz-executor796 Not tainted 5.10.187-syzkaller-00057-g8a427269c016 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 __kasan_report mm/kasan/report.c:439 [inline]
 kasan_report+0x167/0x1c0 mm/kasan/report.c:452
 kasan_check_range+0x293/0x2a0 mm/kasan/generic.c:189
 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_inc_return include/asm-generic/atomic-instrumented.h:250 [inline]
 ihold+0x20/0x60 fs/inode.c:423
 backing_data_changed+0x1d9/0x4f0 fs/fuse/dir.c:193
 fuse_dentry_revalidate+0x826/0xe70 fs/fuse/dir.c:302
 d_revalidate fs/namei.c:780 [inline]
 lookup_dcache fs/namei.c:1505 [inline]
 __lookup_hash+0x1b3/0x290 fs/namei.c:1526
 do_renameat2+0x624/0x1130 fs/namei.c:4560
 __do_sys_rename fs/namei.c:4651 [inline]
 __se_sys_rename fs/namei.c:4649 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:4649
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7fb566e2f739
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb566dd0218 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007fb566ebe3f8 RCX: 00007fb566e2f739
RDX: 00007fb566e2f739 RSI: 0000000020000140 RDI: 0000000020000100
RBP: 00007fb566ebe3f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb566e8b09c
R13: 000000000000006e R14: 0030656c69662f30 R15: 00007fb566e89098
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000170
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 11ea09067 P4D 11ea09067 PUD 11ea0a067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 290 Comm: syz-executor796 Tainted: G    B             5.10.187-syzkaller-00057-g8a427269c016 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:arch_atomic_inc_return include/linux/atomic-arch-fallback.h:286 [inline]
RIP: 0010:atomic_inc_return include/asm-generic/atomic-instrumented.h:251 [inline]
RIP: 0010:ihold+0x25/0x60 fs/inode.c:423
Code: 00 00 00 00 00 55 48 89 e5 41 56 53 49 89 fe e8 71 a7 b3 ff 49 8d be 70 01 00 00 be 04 00 00 00 e8 30 d8 f0 ff bb 01 00 00 00 <f0> 41 0f c1 9e 70 01 00 00 ff c3 bf 02 00 00 00 89 de e8 f4 aa b3
RSP: 0018:ffffc9000091f8c0 EFLAGS: 00010246
RAX: ffff88811ea61300 RBX: 0000000000000001 RCX: ffff88811ea613c0
RDX: 0000000000000000 RSI: 0000000000000286 RDI: 00000000ffffffff
RBP: ffffc9000091f8d0 R08: ffffffff813e28eb R09: 0000000000000003
R10: fffffbfff0e0fe48 R11: dffffc0000000001 R12: ffffc9000091f960
R13: 1ffff92000123f24 R14: 0000000000000000 R15: ffff88811c0a9200
FS:  00007fb566dd06c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 000000011e7ba000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 backing_data_changed+0x1d9/0x4f0 fs/fuse/dir.c:193
 fuse_dentry_revalidate+0x826/0xe70 fs/fuse/dir.c:302
 d_revalidate fs/namei.c:780 [inline]
 lookup_dcache fs/namei.c:1505 [inline]
 __lookup_hash+0x1b3/0x290 fs/namei.c:1526
 do_renameat2+0x624/0x1130 fs/namei.c:4560
 __do_sys_rename fs/namei.c:4651 [inline]
 __se_sys_rename fs/namei.c:4649 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:4649
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7fb566e2f739
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb566dd0218 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007fb566ebe3f8 RCX: 00007fb566e2f739
RDX: 00007fb566e2f739 RSI: 0000000020000140 RDI: 0000000020000100
RBP: 00007fb566ebe3f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb566e8b09c
R13: 000000000000006e R14: 0030656c69662f30 R15: 00007fb566e89098
Modules linked in:
CR2: 0000000000000170
---[ end trace e43da1dc2f7c0628 ]---
RIP: 0010:arch_atomic_inc_return include/linux/atomic-arch-fallback.h:286 [inline]
RIP: 0010:atomic_inc_return include/asm-generic/atomic-instrumented.h:251 [inline]
RIP: 0010:ihold+0x25/0x60 fs/inode.c:423
Code: 00 00 00 00 00 55 48 89 e5 41 56 53 49 89 fe e8 71 a7 b3 ff 49 8d be 70 01 00 00 be 04 00 00 00 e8 30 d8 f0 ff bb 01 00 00 00 <f0> 41 0f c1 9e 70 01 00 00 ff c3 bf 02 00 00 00 89 de e8 f4 aa b3
RSP: 0018:ffffc9000091f8c0 EFLAGS: 00010246
RAX: ffff88811ea61300 RBX: 0000000000000001 RCX: ffff88811ea613c0
RDX: 0000000000000000 RSI: 0000000000000286 RDI: 00000000ffffffff
RBP: ffffc9000091f8d0 R08: ffffffff813e28eb R09: 0000000000000003
R10: fffffbfff0e0fe48 R11: dffffc0000000001 R12: ffffc9000091f960
R13: 1ffff92000123f24 R14: 0000000000000000 R15: ffff88811c0a9200
FS:  00007fb566dd06c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 000000011e7ba000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	00 55 48             	add    %dl,0x48(%rbp)
   7:	89 e5                	mov    %esp,%ebp
   9:	41 56                	push   %r14
   b:	53                   	push   %rbx
   c:	49 89 fe             	mov    %rdi,%r14
   f:	e8 71 a7 b3 ff       	call   0xffb3a785
  14:	49 8d be 70 01 00 00 	lea    0x170(%r14),%rdi
  1b:	be 04 00 00 00       	mov    $0x4,%esi
  20:	e8 30 d8 f0 ff       	call   0xfff0d855
  25:	bb 01 00 00 00       	mov    $0x1,%ebx
* 2a:	f0 41 0f c1 9e 70 01 	lock xadd %ebx,0x170(%r14) <-- trapping instruction
  31:	00 00
  33:	ff c3                	inc    %ebx
  35:	bf 02 00 00 00       	mov    $0x2,%edi
  3a:	89 de                	mov    %ebx,%esi
  3c:	e8                   	.byte 0xe8
  3d:	f4                   	hlt
  3e:	aa                   	stos   %al,%es:(%rdi)
  3f:	b3                   	.byte 0xb3

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/08/20 07:19 android13-5.10-lts 8a427269c016 d216d8a0 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Write in backing_data_changed
2023/10/01 01:21 android13-5.10-lts a27512601c2d 8e26a358 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Write in backing_data_changed
2023/08/20 06:40 android13-5.10-lts 8a427269c016 d216d8a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Write in backing_data_changed
* Struck through repros no longer work on HEAD.