syzbot


WARNING in fscrypt_fname_siphash

Status: upstream: reported C repro on 2025/07/17 06:42
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+29b46d845126c2686055@syzkaller.appspotmail.com
First crash: 8d23h, last: 5d18h
Bug presence (2)
Date Name Commit Repro Result
2025/07/20 linux-6.6.y (ToT) d96eb99e2f0e C [report] WARNING in fscrypt_fname_siphash
2025/07/20 upstream (ToT) f4a40a4282f4 C Didn't crash
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in fscrypt_fname_siphash origin:lts-only -1 C done 28 9d03h 278d 0/3 upstream: reported C repro on 2024/10/20 08:52
upstream WARNING in fscrypt_fname_siphash ext4 fscrypt -1 C unreliable 32 328d 422d 28/29 fixed on 2024/10/22 11:57
linux-6.1 WARNING in fscrypt_fname_siphash -1 1 424d 424d 0/3 auto-obsoleted due to no activity on 2024/09/04 07:37
linux-6.1 WARNING in fscrypt_fname_siphash (2) origin:lts-only -1 C done 18 3d03h 258d 0/3 upstream: reported C repro on 2024/11/10 06:13

Sample crash report:
EXT4-fs (loop0): encrypted files will use data=ordered instead of data journaling mode
EXT4-fs (loop0): 1 truncate cleaned up
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
fscrypt: AES-256-CTS-CBC using implementation "cts-cbc-aes-aesni"
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5947 at fs/crypto/fname.c:567 fscrypt_fname_siphash+0xa8/0xe0 fs/crypto/fname.c:567
Modules linked in:
CPU: 1 PID: 5947 Comm: syz.0.16 Not tainted 6.6.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:fscrypt_fname_siphash+0xa8/0xe0 fs/crypto/fname.c:567
Code: 48 89 d8 48 c1 e8 03 42 0f b6 04 20 84 c0 75 32 8b 33 49 83 c6 40 4c 89 f2 5b 41 5c 41 5e 41 5f e9 cd 1e 5a 08 e8 d8 46 82 ff <0f> 0b eb b3 44 89 f9 80 e1 07 38 c1 7c 9e 4c 89 ff e8 f2 8b d9 ff
RSP: 0018:ffffc90003456dd8 EFLAGS: 00010293
RAX: ffffffff82034f58 RBX: ffffc90003456ee0 RCX: ffff8880236d5a00
RDX: 0000000000000000 RSI: ffffc90003456ee0 RDI: ffff888070f066b0
RBP: ffffc90003456f50 R08: ffff8880236d5a00 R09: 0000000000000007
R10: 0000000000000006 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88802edb6c08 R14: ffff888070fe5000 R15: ffff888070fe5050
FS:  0000555584fd1500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcb75afa440 CR3: 000000002c421000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 __ext4fs_dirhash+0x33f/0xe20 fs/ext4/hash.c:268
 ext4fs_dirhash+0x144/0x2c0 fs/ext4/hash.c:322
 htree_dirblock_to_tree+0x6cd/0xe70 fs/ext4/namei.c:1125
 ext4_htree_fill_tree+0x5db/0x10f0 fs/ext4/namei.c:1220
 ext4_dx_readdir fs/ext4/dir.c:608 [inline]
 ext4_readdir+0x2b1d/0x39d0 fs/ext4/dir.c:145
 iterate_dir+0x1c2/0x580 fs/readdir.c:106
 ovl_dir_read+0xfc/0x560 fs/overlayfs/readdir.c:309
 ovl_check_d_type_supported+0x99/0x100 fs/overlayfs/readdir.c:1065
 ovl_make_workdir fs/overlayfs/super.c:733 [inline]
 ovl_get_workdir+0x487/0x1740 fs/overlayfs/super.c:874
 ovl_fill_super+0x1345/0x3560 fs/overlayfs/super.c:1427
 vfs_get_super fs/super.c:1346 [inline]
 get_tree_nodev+0xb5/0x140 fs/super.c:1365
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3366
 do_mount fs/namespace.c:3706 [inline]
 __do_sys_mount fs/namespace.c:3915 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3892
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe61398e9a9
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:00007ffc3fede488 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe613bb5fa0 RCX: 00007fe61398e9a9
RDX: 0000200000000b80 RSI: 0000200000000100 RDI: 0000000000000000
RBP: 00007fe613a10d69 R08: 0000200000000200 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe613bb5fa0 R14: 00007fe613bb5fa0 R15: 0000000000000005
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/19 12:55 linux-6.6.y d96eb99e2f0e 7117feec .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (clean fs)] ci2-linux-6-6-kasan WARNING in fscrypt_fname_siphash
2025/07/17 06:41 linux-6.6.y 9247f4e6573a 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in fscrypt_fname_siphash
2025/07/17 06:41 linux-6.6.y 9247f4e6573a 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in fscrypt_fname_siphash
* Struck through repros no longer work on HEAD.