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panic: item_ops-NUM direntry_check_left: free space NUM, entry_count NUM

Status: upstream: reported C repro on 2025/11/12 05:44
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+0538b14992b3023e8bd1@syzkaller.appspotmail.com
First crash: 34d, last: 13d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/11/16 linux-5.15.y (ToT) cc5ec8769306 C [report] panic: item_ops-NUM direntry_check_left: free space NUM, entry_count NUM
2025/11/16 upstream (ToT) 6a23ae0a96a6 C Didn't crash
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream panic: item_ops-NUM direntry_check_left: free space NUM, entry_count NUM fs 2 1 1051d 1047d 0/29 auto-obsoleted due to no activity on 2023/05/29 16:12
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/12/02 12:48 10m retest repro linux-5.15.y report log
2025/12/02 12:48 12m retest repro linux-5.15.y report log
2025/12/02 12:48 10m retest repro linux-5.15.y report log

Sample crash report:
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using tea hash to sort names
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
REISERFS warning: vs-16090 direntry_bytes_number: bytes number is asked for direntry
REISERFS panic: item_ops-1 direntry_check_left: free space 124, entry_count 3
------------[ cut here ]------------
kernel BUG at fs/reiserfs/prints.c:390!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4349 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__reiserfs_panic+0xf7/0x140 fs/reiserfs/prints.c:390
Code: 1b 8a 48 c7 c2 e0 4e 1b 8a 48 0f 44 d0 4c 0f 44 f0 48 c7 c7 00 50 1b 8a 4c 89 f6 48 89 d9 49 c7 c0 20 9e 1e 96 e8 d9 51 ff ff <0f> 0b e8 e2 2e d8 f7 49 81 c7 a8 06 00 00 4d 85 f6 48 c7 c0 c0 4e
RSP: 0018:ffffc900032fe980 EFLAGS: 00010246
RAX: 000000000000004d RBX: ffffffff8bb719d7 RCX: 06aa523b839c5300
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900032fea68 R08: dffffc0000000000 R09: ffffed10172067b0
R10: ffffed10172067b0 R11: 1ffff110172067af R12: ffffffff8a1ba960
R13: ffffc900032fe9a0 R14: ffffffff8a1ba940 R15: 0000000000000000
FS:  00005555886bc500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f42df6ac000 CR3: 0000000072b16000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 direntry_check_left+0x273/0x300 fs/reiserfs/item_ops.c:542
 get_num_ver+0x618/0xfd0 fs/reiserfs/fix_node.c:515
 ip_check_balance fs/reiserfs/fix_node.c:1523 [inline]
 check_balance fs/reiserfs/fix_node.c:2083 [inline]
 fix_nodes+0x2867/0x82d0 fs/reiserfs/fix_node.c:2635
 reiserfs_paste_into_item+0x5c8/0x7e0 fs/reiserfs/stree.c:2130
 reiserfs_get_block+0x1bde/0x4100 fs/reiserfs/inode.c:1077
 __block_write_begin_int+0x54e/0x15a0 fs/buffer.c:2012
 reiserfs_write_begin+0x34b/0x810 fs/reiserfs/inode.c:2790
 generic_cont_expand_simple+0xe9/0x190 fs/buffer.c:2362
 reiserfs_setattr+0x42f/0x1010 fs/reiserfs/inode.c:3319
 notify_change+0xbcd/0xee0 fs/attr.c:505
 do_truncate+0x197/0x220 fs/open.c:65
 do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f94715de6c9
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:00007ffdcf92d7d8 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f9471834fa0 RCX: 00007f94715de6c9
RDX: 0000000000000000 RSI: 0000000008008976 RDI: 0000000000000006
RBP: 00007f9471660f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9471834fa0 R14: 00007f9471834fa0 R15: 0000000000000002
 </TASK>
Modules linked in:
---[ end trace 9ae833b970a76332 ]---
RIP: 0010:__reiserfs_panic+0xf7/0x140 fs/reiserfs/prints.c:390
Code: 1b 8a 48 c7 c2 e0 4e 1b 8a 48 0f 44 d0 4c 0f 44 f0 48 c7 c7 00 50 1b 8a 4c 89 f6 48 89 d9 49 c7 c0 20 9e 1e 96 e8 d9 51 ff ff <0f> 0b e8 e2 2e d8 f7 49 81 c7 a8 06 00 00 4d 85 f6 48 c7 c0 c0 4e
RSP: 0018:ffffc900032fe980 EFLAGS: 00010246
RAX: 000000000000004d RBX: ffffffff8bb719d7 RCX: 06aa523b839c5300
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900032fea68 R08: dffffc0000000000 R09: ffffed10172067b0
R10: ffffed10172067b0 R11: 1ffff110172067af R12: ffffffff8a1ba960
R13: ffffc900032fe9a0 R14: ffffffff8a1ba940 R15: 0000000000000000
FS:  00005555886bc500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f42df6ac000 CR3: 0000000072b16000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/12 09:55 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan panic: item_ops-NUM direntry_check_left: free space NUM, entry_count NUM
2025/11/12 08:56 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan panic: item_ops-NUM direntry_check_left: free space NUM, entry_count NUM
2025/11/12 07:49 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan panic: item_ops-NUM direntry_check_left: free space NUM, entry_count NUM
2025/11/12 06:46 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan panic: item_ops-NUM direntry_check_left: free space NUM, entry_count NUM
2025/11/12 05:43 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan panic: item_ops-NUM direntry_check_left: free space NUM, entry_count NUM
* Struck through repros no longer work on HEAD.