syzbot


kernel BUG in ocfs2_page_mkwrite (3)

Status: upstream: reported on 2025/11/01 09:03
Subsystems: ocfs2
[Documentation on labels]
Reported-by: syzbot+ea5aff81e35d189b9335@syzkaller.appspotmail.com
First crash: 57d, last: 22d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ocfs2?] kernel BUG in ocfs2_page_mkwrite (3) 0 (1) 2025/11/01 09:03
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in ocfs2_page_mkwrite (2) ocfs2 -1 C 112 151d 349d 0/29 auto-obsoleted due to no activity on 2025/10/04 07:06
upstream kernel BUG in ocfs2_page_mkwrite ocfs2 -1 1 455d 451d 0/29 auto-obsoleted due to no activity on 2025/01/03 15:18

Sample crash report:
loop0: detected capacity change from 0 to 32768
=======================================================
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
ocfs2: Unknown parameter './bus'
loop0: detected capacity change from 32768 to 0
(syz.0.0,5334,0):ocfs2_extend_trans:460 ERROR: status = -30
(syz.0.0,5334,0):ocfs2_try_to_merge_extent:3817 ERROR: status = -30
(syz.0.0,5334,0):__ocfs2_journal_access:727 ERROR: Error -30 getting 1 access to buffer!
(syz.0.0,5334,0):ocfs2_write_end_nolock:1944 ERROR: status = -30
------------[ cut here ]------------
kernel BUG at fs/ocfs2/mmap.c:107!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5334 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__ocfs2_page_mkwrite fs/ocfs2/mmap.c:107 [inline]
RIP: 0010:ocfs2_page_mkwrite+0xc37/0xc40 fs/ocfs2/mmap.c:144
Code: 07 e8 ed 16 16 fe eb 0d 48 ff cb e8 e3 16 16 fe 48 89 5c 24 08 49 be 00 00 00 00 00 fc ff df e9 cb f4 ff ff e8 ca 16 16 fe 90 <0f> 0b cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000d2b74e0 EFLAGS: 00010246
RAX: ffffffff83aa7626 RBX: 00000000ffffffe2 RCX: 0000000000100000
RDX: ffffc9000e352000 RSI: 00000000000fffff RDI: 0000000000100000
RBP: ffffc9000d2b7680 R08: ffffffff8f7d1277 R09: 1ffffffff1efa24e
R10: dffffc0000000000 R11: fffffbfff1efa24f R12: ffffea00014fc440
R13: 0000000000000100 R14: 0000000000000000 R15: 00000000000000f4
FS:  00007fe511fe56c0(0000) GS:ffff88808d722000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000100000 CR3: 0000000000ce3000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 do_page_mkwrite+0x14d/0x310 mm/memory.c:3489
 do_shared_fault mm/memory.c:5792 [inline]
 do_fault mm/memory.c:5854 [inline]
 do_pte_missing mm/memory.c:4362 [inline]
 handle_pte_fault mm/memory.c:6195 [inline]
 __handle_mm_fault+0x1916/0x5400 mm/memory.c:6336
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6505
 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74
Code: cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 <f3> a4 e9 bf 31 04 00 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48
RSP: 0018:ffffc9000d2b7ae8 EFLAGS: 00050246
RAX: ffffffff848cd301 RBX: 0000000000000040 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffffc9000d2b7b80 RDI: 0000200000100000
RBP: ffffc9000d2b7c30 R08: ffffc9000d2b7bbf R09: 1ffff92001a56f77
R10: dffffc0000000000 R11: fffff52001a56f78 R12: 0000200000100040
R13: 00007ffffffff000 R14: ffffc9000d2b7b80 R15: 0000200000100000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
 _inline_copy_to_user include/linux/uaccess.h:197 [inline]
 _copy_to_user+0x8a/0xb0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 rng_dev_read+0x3f2/0x770 drivers/char/hw_random/core.c:258
 do_loop_readv_writev fs/read_write.c:847 [inline]
 vfs_readv+0x5aa/0x850 fs/read_write.c:1020
 do_preadv fs/read_write.c:1132 [inline]
 __do_sys_preadv fs/read_write.c:1179 [inline]
 __se_sys_preadv fs/read_write.c:1174 [inline]
 __x64_sys_preadv+0x197/0x2a0 fs/read_write.c:1174
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe51118f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe511fe5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007fe5113e5fa0 RCX: 00007fe51118f7c9
RDX: 0000000000000001 RSI: 0000200000000240 RDI: 000000000000000a
RBP: 00007fe511213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe5113e6038 R14: 00007fe5113e5fa0 R15: 00007ffe26280928
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__ocfs2_page_mkwrite fs/ocfs2/mmap.c:107 [inline]
RIP: 0010:ocfs2_page_mkwrite+0xc37/0xc40 fs/ocfs2/mmap.c:144
Code: 07 e8 ed 16 16 fe eb 0d 48 ff cb e8 e3 16 16 fe 48 89 5c 24 08 49 be 00 00 00 00 00 fc ff df e9 cb f4 ff ff e8 ca 16 16 fe 90 <0f> 0b cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000d2b74e0 EFLAGS: 00010246
RAX: ffffffff83aa7626 RBX: 00000000ffffffe2 RCX: 0000000000100000
RDX: ffffc9000e352000 RSI: 00000000000fffff RDI: 0000000000100000
RBP: ffffc9000d2b7680 R08: ffffffff8f7d1277 R09: 1ffffffff1efa24e
R10: dffffc0000000000 R11: fffffbfff1efa24f R12: ffffea00014fc440
R13: 0000000000000100 R14: 0000000000000000 R15: 00000000000000f4
FS:  00007fe511fe56c0(0000) GS:ffff88808d722000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000100000 CR3: 0000000000ce3000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	cc                   	int3
   1:	cc                   	int3
   2:	cc                   	int3
   3:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
   a:	00 00 00
   d:	0f 1f 00             	nopl   (%rax)
  10:	48 8b 06             	mov    (%rsi),%rax
  13:	48 89 07             	mov    %rax,(%rdi)
  16:	48 83 c6 08          	add    $0x8,%rsi
  1a:	48 83 c7 08          	add    $0x8,%rdi
  1e:	83 e9 08             	sub    $0x8,%ecx
  21:	74 db                	je     0xfffffffe
  23:	83 f9 08             	cmp    $0x8,%ecx
  26:	73 e8                	jae    0x10
  28:	eb c5                	jmp    0xffffffef
* 2a:	f3 a4                	rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction
  2c:	e9 bf 31 04 00       	jmp    0x431f0
  31:	48 8b 06             	mov    (%rsi),%rax
  34:	48 89 07             	mov    %rax,(%rdi)
  37:	48 8d 47 08          	lea    0x8(%rdi),%rax
  3b:	48 83 e0 f8          	and    $0xfffffffffffffff8,%rax
  3f:	48                   	rex.W

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/02 05:23 upstream 1d18101a644e d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in ocfs2_page_mkwrite
2025/11/04 18:29 upstream c9cfc122f037 686bf657 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in ocfs2_page_mkwrite
2025/10/28 08:58 upstream fd57572253bc fd2207e7 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root kernel BUG in ocfs2_page_mkwrite
* Struck through repros no longer work on HEAD.