syzbot


BUG: unable to handle kernel paging request in bch2_dirent_to_text

Status: upstream: reported C repro on 2024/07/18 01:20
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+1a11884d9c9f1353942d@syzkaller.appspotmail.com
First crash: 352d, last: 41d
Cause bisection: introduced by (bisect log) :
commit 03ef80b469d5d83530ce1ce15be78a40e5300f9b
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date: Sat Sep 23 22:41:51 2023 +0000

  bcachefs: Ignore unknown mount options

Crash: invalid opcode in corrupted (log)
Repro: C syz .config
  
Fix bisection: failed (error log, bisect log)
  
Discussions (4)
Title Replies (including bot) Last reply
[syzbot] Monthly bcachefs report (Sep 2024) 0 (1) 2024/09/13 10:03
[PATCH] bcachefs: Add check for the size of combined key and value 2 (2) 2024/08/13 12:17
[PATCH] bcachefs: Add check for the size of combined key and value 1 (1) 2024/08/04 09:20
[syzbot] [bcachefs?] BUG: unable to handle kernel paging request in bch2_dirent_to_text 0 (1) 2024/07/18 01:20
Last patch testing requests (7)
Created Duration User Patch Repo Result
2025/06/08 03:17 22m retest repro upstream OK log
2025/05/24 08:29 18m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/03/30 02:40 14m retest repro upstream report log
2025/03/15 01:52 1h11m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/03/15 01:43 30m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2024/12/28 18:34 17m retest repro upstream report log
2024/07/31 09:25 12m retest repro upstream report log
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2024/10/15 00:50 0m bisect fix upstream error job log
2024/09/04 18:52 3h09m bisect fix upstream OK (0) job log log

Sample crash report:
loop0: detected capacity change from 0 to 32768
Unable to handle kernel paging request at virtual address ffff600118dc3959
KASAN: probably wild-memory-access in range [0xffff0008c6e1cac8-0xffff0008c6e1cacf]
Mem abort info:
  ESR = 0x0000000096000005
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x05: level 1 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000001a50a7000
[ffff600118dc3959] pgd=0000000000000000, p4d=0000000233926003, pud=0000000000000000
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 UID: 0 PID: 6442 Comm: syz-executor244 Not tainted 6.14.0-rc4-syzkaller-g017f704fbfb1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : bch2_dirent_name_bytes fs/bcachefs/dirent.c:23 [inline]
pc : bch2_dirent_get_name fs/bcachefs/dirent.c:37 [inline]
pc : bch2_dirent_to_text+0xcc/0x2f4 fs/bcachefs/dirent.c:152
lr : bch2_dirent_get_name fs/bcachefs/dirent.c:37 [inline]
lr : bch2_dirent_to_text+0xbc/0x2f4 fs/bcachefs/dirent.c:152
sp : ffff8000a4b06560
x29: ffff8000a4b06570 x28: ffff0000c6e1ca74 x27: ffff0000c6e1cad0
x26: ffff8000a4b06eac x25: ffff8000a4b06ea8 x24: dfff800000000000
x23: dfff800000000000 x22: 0000000000000000 x21: ffff0008c6e1cac8
x20: ffff0000c6e1caf8 x19: ffff8000a4b06ea0 x18: ffff0000cc7be858
x17: 7972746e655f7465 x16: ffff80008b79c320 x15: 0000000000000001
x14: 0000000000000001 x13: 0000000000000000 x12: 0000000000000007
x11: 0000000000000020 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : 1fffe00118dc3959 x7 : ffff8000a4b06480 x6 : 000000000000003a
x5 : ffff0000c69bc830 x4 : ffff80008bd08da2 x3 : ffff0000c6e1caf8
x2 : ffff0000c6e1cad0 x1 : ffffffffffffffd8 x0 : 0000000000000009
Call trace:
 bch2_dirent_name_bytes fs/bcachefs/dirent.c:23 [inline] (P)
 bch2_dirent_get_name fs/bcachefs/dirent.c:37 [inline] (P)
 bch2_dirent_to_text+0xcc/0x2f4 fs/bcachefs/dirent.c:152 (P)
 bch2_val_to_text fs/bcachefs/bkey_methods.c:305 [inline]
 bch2_bkey_val_to_text+0xfc/0x140 fs/bcachefs/bkey_methods.c:315
 journal_entry_btree_keys_to_text+0x460/0x9ac fs/bcachefs/journal_io.c:427
 journal_entry_btree_root_to_text+0x34/0x48 fs/bcachefs/journal_io.c:471
 bch2_journal_entry_to_text+0xe8/0x160 fs/bcachefs/journal_io.c:850
 bch2_sb_clean_to_text+0x130/0x224 fs/bcachefs/sb-clean.c:256
 __bch2_sb_field_to_text fs/bcachefs/super-io.c:1316 [inline]
 bch2_sb_field_to_text+0x1a4/0x234 fs/bcachefs/super-io.c:1332
 bch2_sb_field_validate+0x1d8/0x2a8 fs/bcachefs/super-io.c:1299
 bch2_sb_validate+0xd54/0x1098 fs/bcachefs/super-io.c:517
 __bch2_read_super+0x9a8/0x1074 fs/bcachefs/super-io.c:878
 bch2_read_super+0x38/0x4c fs/bcachefs/super-io.c:898
 bch2_fs_open+0x238/0x299c fs/bcachefs/super.c:2032
 bch2_fs_get_tree+0x58c/0x11d4 fs/bcachefs/fs.c:2190
 vfs_get_tree+0x90/0x28c fs/super.c:1814
 do_new_mount+0x278/0x900 fs/namespace.c:3560
 path_mount+0x590/0xe04 fs/namespace.c:3887
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount fs/namespace.c:4088 [inline]
 __arm64_sys_mount+0x4f4/0x5d0 fs/namespace.c:4088
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Code: 51001ac8 531d72d6 8b284e95 d343fea8 (38776908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	51001ac8 	sub	w8, w22, #0x6
   4:	531d72d6 	lsl	w22, w22, #3
   8:	8b284e95 	add	x21, x20, w8, uxtw #3
   c:	d343fea8 	lsr	x8, x21, #3
* 10:	38776908 	ldrb	w8, [x8, x23] <-- trapping instruction

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/28 21:36 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 017f704fbfb1 1e7a43e1 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bch2_dirent_to_text
2024/07/17 09:09 upstream 0434dbe32053 215bec2d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs BUG: unable to handle kernel paging request in bch2_dirent_to_text
2024/07/17 08:00 upstream 0434dbe32053 215bec2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs BUG: unable to handle kernel paging request in bch2_dirent_to_text
* Struck through repros no longer work on HEAD.