syzbot


stack segment fault in release_metapage

Status: upstream: reported C repro on 2025/08/20 09:22
Subsystems: jfs
[Documentation on labels]
Reported-by: syzbot+43706fd1eb4c8dccdfe6@syzkaller.appspotmail.com
First crash: 14d, last: 3d20h
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [jfs?] stack segment fault in release_metapage 0 (1) 2025/08/20 09:22

Sample crash report:
Oops: stack segment: 0000 [#1] SMP KASAN [   95.155857][  T122] Oops: stack segment: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 122 Comm: jfsCommit Tainted: G        W           syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:folio_flags include/linux/page-flags.h:360 [inline]
RIP: 0010:folio_trylock include/linux/pagemap.h:1096 [inline]
RIP: 0010:folio_lock include/linux/pagemap.h:1132 [inline]
RIP: 0010:release_metapage+0x9e/0xab0 fs/jfs/jfs_metapage.c:870
Code: 04 00 00 e8 b4 c9 87 fe 48 c7 c7 51 f4 05 8d be 6b 04 00 00 e8 43 ba 5a fe 2e 2e 2e 31 c0 49 8d 5c 24 08 48 89 dd 48 c1 ed 03 <42> 80 7c 2d 00 00 74 08 48 89 df e8 a2 fc e6 fe 4c 8b 3b 4c 89 fe
RSP: 0018:ffffc900039976d8 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000008 RCX: ffff88801ebc3b80
RDX: ffff88801ebc3b80 RSI: 000000000000046b RDI: ffffffff8d05f451
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100b48576e R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88805a42bb48 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881269c5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555561a8e648 CR3: 0000000023fb6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 xtTruncate+0xe84/0x2e70 fs/jfs/jfs_xtree.c:-1
 jfs_free_zero_link+0x33a/0x4a0 fs/jfs/namei.c:759
 jfs_evict_inode+0x363/0x440 fs/jfs/inode.c:153
 evict+0x501/0x9c0 fs/inode.c:810
 txLazyCommit fs/jfs/jfs_txnmgr.c:2664 [inline]
 jfs_lazycommit+0x3f1/0xa10 fs/jfs/jfs_txnmgr.c:2733
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:folio_flags include/linux/page-flags.h:360 [inline]
RIP: 0010:folio_trylock include/linux/pagemap.h:1096 [inline]
RIP: 0010:folio_lock include/linux/pagemap.h:1132 [inline]
RIP: 0010:release_metapage+0x9e/0xab0 fs/jfs/jfs_metapage.c:870
Code: 04 00 00 e8 b4 c9 87 fe 48 c7 c7 51 f4 05 8d be 6b 04 00 00 e8 43 ba 5a fe 2e 2e 2e 31 c0 49 8d 5c 24 08 48 89 dd 48 c1 ed 03 <42> 80 7c 2d 00 00 74 08 48 89 df e8 a2 fc e6 fe 4c 8b 3b 4c 89 fe
RSP: 0018:ffffc900039976d8 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000008 RCX: ffff88801ebc3b80
RDX: ffff88801ebc3b80 RSI: 000000000000046b RDI: ffffffff8d05f451
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100b48576e R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88805a42bb48 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881269c5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555561a8e648 CR3: 00000000366e0000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	04 00                	add    $0x0,%al
   2:	00 e8                	add    %ch,%al
   4:	b4 c9                	mov    $0xc9,%ah
   6:	87 fe                	xchg   %edi,%esi
   8:	48 c7 c7 51 f4 05 8d 	mov    $0xffffffff8d05f451,%rdi
   f:	be 6b 04 00 00       	mov    $0x46b,%esi
  14:	e8 43 ba 5a fe       	call   0xfe5aba5c
  19:	2e 2e 2e 31 c0       	cs cs cs xor %eax,%eax
  1e:	49 8d 5c 24 08       	lea    0x8(%r12),%rbx
  23:	48 89 dd             	mov    %rbx,%rbp
  26:	48 c1 ed 03          	shr    $0x3,%rbp
* 2a:	42 80 7c 2d 00 00    	cmpb   $0x0,0x0(%rbp,%r13,1) <-- trapping instruction
  30:	74 08                	je     0x3a
  32:	48 89 df             	mov    %rbx,%rdi
  35:	e8 a2 fc e6 fe       	call   0xfee6fcdc
  3a:	4c 8b 3b             	mov    (%rbx),%r15
  3d:	4c 89 fe             	mov    %r15,%rsi

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/20 09:21 upstream b19a97d57c15 79512909 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-upstream-fs stack segment fault in release_metapage
2025/08/21 16:20 upstream 068a56e56fa8 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs stack segment fault in release_metapage
2025/08/20 04:50 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs stack segment fault in release_metapage
2025/08/10 17:52 upstream 2b38afce25c4 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs stack segment fault in release_metapage
* Struck through repros no longer work on HEAD.