syzbot


general protection fault in f2fs_drop_extent_tree

Status: fixed on 2023/10/12 12:48
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+f4649be1be739e030111@syzkaller.appspotmail.com
Fix commit: 458c15dfbce6 f2fs: don't reset unchangable mount option in f2fs_remount()
First crash: 529d, last: 529d
Cause bisection: failed (error log, bisect log)
  
Fix bisection: fixed by (bisect log) :
commit 458c15dfbce62c35fefd9ca637b20a051309c9f1
Author: Chao Yu <chao@kernel.org>
Date: Tue May 23 03:58:22 2023 +0000

  f2fs: don't reset unchangable mount option in f2fs_remount()

  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [f2fs?] general protection fault in f2fs_drop_extent_tree 1 (3) 2023/08/02 14:26
[syzbot] Monthly f2fs report (Jul 2023) 0 (1) 2023/07/07 08:54
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 general protection fault in f2fs_drop_extent_tree origin:upstream missing-backport C unreliable 1 364d 531d 0/3 upstream: reported C repro on 2023/06/23 01:12

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f]
CPU: 0 PID: 5015 Comm: syz-executor425 Not tainted 6.4.0-rc7-syzkaller-00226-ga92b7d26c743 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:__lock_acquire+0xe01/0x5f30 kernel/locking/lockdep.c:4956
Code: 00 00 3b 05 01 b0 59 0f 0f 87 7a 09 00 00 41 be 01 00 00 00 e9 84 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 9e 33 00 00 49 81 3c 24 20 38 16 90 0f 84 cd f2
RSP: 0018:ffffc90003b6f9d8 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: 1ffff9200076df6c RCX: 0000000000000000
RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000048
RBP: ffff88802834d940 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000048
R13: 0000000000000000 R14: 0000000000000048 R15: 0000000000000000
FS:  00007f2b8ef07700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2b8efac0c8 CR3: 00000000235f8000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5705 [inline]
 lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670
 __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline]
 _raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300
 __drop_extent_tree fs/f2fs/extent_cache.c:1100 [inline]
 f2fs_drop_extent_tree+0xf0/0x3a0 fs/f2fs/extent_cache.c:1116
 f2fs_insert_range fs/f2fs/file.c:1664 [inline]
 f2fs_fallocate+0xce5/0x36d0 fs/f2fs/file.c:1838
 vfs_fallocate+0x48b/0xe40 fs/open.c:324
 ksys_fallocate fs/open.c:347 [inline]
 __do_sys_fallocate fs/open.c:355 [inline]
 __se_sys_fallocate fs/open.c:353 [inline]
 __x64_sys_fallocate+0xd3/0x140 fs/open.c:353
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f2b8ef5b459
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2b8ef072f8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f2b8efe57a0 RCX: 00007f2b8ef5b459
RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000000000000005
RBP: 00007f2b8efb27f8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010000 R11: 0000000000000246 R12: 00007f2b8efb26c0
R13: 0030656c69662f2e R14: 4b55cd3db08b6c4e R15: 00007f2b8efe57a8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0xe01/0x5f30 kernel/locking/lockdep.c:4956
Code: 00 00 3b 05 01 b0 59 0f 0f 87 7a 09 00 00 41 be 01 00 00 00 e9 84 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 9e 33 00 00 49 81 3c 24 20 38 16 90 0f 84 cd f2
RSP: 0018:ffffc90003b6f9d8 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: 1ffff9200076df6c RCX: 0000000000000000
RDX: 0000000000000009 RSI: 0000000000000000 RDI: 0000000000000048
RBP: ffff88802834d940 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000048
R13: 0000000000000000 R14: 0000000000000048 R15: 0000000000000000
FS:  00007f2b8ef07700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2b8efac0c8 CR3: 00000000235f8000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	3b 05 01 b0 59 0f    	cmp    0xf59b001(%rip),%eax        # 0xf59b009
   8:	0f 87 7a 09 00 00    	ja     0x988
   e:	41 be 01 00 00 00    	mov    $0x1,%r14d
  14:	e9 84 00 00 00       	jmpq   0x9d
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	4c 89 e2             	mov    %r12,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 9e 33 00 00    	jne    0x33d2
  34:	49 81 3c 24 20 38 16 	cmpq   $0xffffffff90163820,(%r12)
  3b:	90
  3c:	0f                   	.byte 0xf
  3d:	84 cd                	test   %cl,%ch
  3f:	f2                   	repnz

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/24 23:20 upstream a92b7d26c743 09ffe269 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-root general protection fault in f2fs_drop_extent_tree
* Struck through repros no longer work on HEAD.