syzbot


general protection fault in detach_extent_buffer_folio

Status: upstream: reported on 2024/06/05 18:01
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+f80b066392366b4af85e@syzkaller.appspotmail.com
Fix commit: f3a5367c679d btrfs: protect folio::private when attaching extent buffer folios
Patched on: [ci-qemu-native-arm64-kvm ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-upstream-gce-leak ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-net-next-test-gce], missing on: [ci-qemu-upstream ci-qemu-upstream-386 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-usb]
First crash: 27d, last: 8d03h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [btrfs?] general protection fault in detach_extent_buffer_folio 0 (1) 2024/06/05 18:01

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc000000002a: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000150-0x0000000000000157]
CPU: 1 PID: 111 Comm: kswapd0 Not tainted 6.10.0-rc2-syzkaller-00097-g2df0193e62cf #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__lock_acquire+0xe3e/0x3b30 kernel/locking/lockdep.c:5005
Code: 11 00 00 39 05 93 a6 1f 12 0f 82 be 05 00 00 ba 01 00 00 00 e9 e4 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 82 1f 00 00 49 81 3c 24 e0 1d e3 92 0f 84 98 f2
RSP: 0018:ffffc90000e3ef10 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000002a RSI: ffff88801b330000 RDI: 0000000000000150
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff8fe2c257 R11: 0000000000000001 R12: 0000000000000150
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88802c100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fba7f2367c0 CR3: 000000001c268000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 detach_extent_buffer_folio+0x33c/0x870 fs/btrfs/extent_io.c:3385
 btrfs_release_extent_buffer_pages+0xaa/0x1b0 fs/btrfs/extent_io.c:3446
 release_extent_buffer+0x240/0x2c0 fs/btrfs/extent_io.c:4074
 try_release_extent_buffer+0x78d/0x9e0 fs/btrfs/extent_io.c:5115
 btree_release_folio+0xbf/0x100 fs/btrfs/disk-io.c:524
 filemap_release_folio+0x1ed/0x280 mm/filemap.c:4173
 shrink_folio_list+0x254a/0x4150 mm/vmscan.c:1394
 evict_folios+0x6e6/0x1bf0 mm/vmscan.c:4553
 try_to_shrink_lruvec+0x618/0x9b0 mm/vmscan.c:4749
 shrink_one+0x3f8/0x7c0 mm/vmscan.c:4788
 shrink_many mm/vmscan.c:4851 [inline]
 lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
 shrink_node mm/vmscan.c:5910 [inline]
 kswapd_shrink_node mm/vmscan.c:6720 [inline]
 balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
 kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0xe3e/0x3b30 kernel/locking/lockdep.c:5005
Code: 11 00 00 39 05 93 a6 1f 12 0f 82 be 05 00 00 ba 01 00 00 00 e9 e4 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 82 1f 00 00 49 81 3c 24 e0 1d e3 92 0f 84 98 f2
RSP: 0018:ffffc90000e3ef10 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000002a RSI: ffff88801b330000 RDI: 0000000000000150
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff8fe2c257 R11: 0000000000000001 R12: 0000000000000150
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88802c100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fba7f2367c0 CR3: 000000001c268000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	11 00                	adc    %eax,(%rax)
   2:	00 39                	add    %bh,(%rcx)
   4:	05 93 a6 1f 12       	add    $0x121fa693,%eax
   9:	0f 82 be 05 00 00    	jb     0x5cd
   f:	ba 01 00 00 00       	mov    $0x1,%edx
  14:	e9 e4 00 00 00       	jmp    0xfd
  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 82 1f 00 00    	jne    0x1fb6
  34:	49 81 3c 24 e0 1d e3 	cmpq   $0xffffffff92e31de0,(%r12)
  3b:	92
  3c:	0f                   	.byte 0xf
  3d:	84                   	.byte 0x84
  3e:	98                   	cwtl
  3f:	f2                   	repnz

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/06 08:43 upstream 2df0193e62cf c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in detach_extent_buffer_folio
2024/06/05 18:00 upstream 71d7b52cc33b c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in detach_extent_buffer_folio
2024/06/02 01:33 upstream ec9eeb89e60d c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in detach_extent_buffer_folio
2024/05/30 14:08 upstream 4a4be1ad3a6e c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in detach_extent_buffer_folio
2024/05/26 22:05 upstream c13320499ba0 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in detach_extent_buffer_folio
2024/05/17 13:49 upstream ea5f6ad9ad96 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 general protection fault in detach_extent_buffer_folio
* Struck through repros no longer work on HEAD.