Hello.
We are Ubisectech Sirius Team, the vulnerability lab of China ValiantSec. Recently, our team has discovered a issue in Linux kernel 6.7. Attached to the email were a PoC file of the issue.
Stack dump:
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WARNING: CPU: 0 PID: 10070 at fs/crypto/fname.c:573 fscrypt_fname_siphash+0xdf/0x120 fs/crypto/fname.c:573
Modules linked in:
CPU: 0 PID: 10070 Comm: syz-executor.2 Not tainted 6.7.0 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:fscrypt_fname_siphash+0xdf/0x120 fs/crypto/fname.c:573
Code: 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 01 00 75 3f 48 8b 7b 08 48 83 c4 10 5b 5d 41 5c e9 d7 79 6e 08 e8 f2 a2 80 ff 90 <0f> 0b 90 eb 93 48 89 14 24 e8 b3 5b d7 ff 48 8b 14 24 eb b7 e8 48
RSP: 0018:ffffc90002887238 EFLAGS: 00010246
RAX: 0000000000040000 RBX: ffffc900028872d0 RCX: ffffc900030cb000
RDX: 0000000000040000 RSI: ffffffff8209535e RDI: 0000000000000001
RBP: ffff888063065180 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 000000008d4c4d91 R12: 0000000000000000
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff888056aba0c4
FS: 00007ff63b86f640(0000) GS:ffff88802c600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff5442398e0 CR3: 0000000057fd8000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
__ext4fs_dirhash+0x36a/0xb60 fs/ext4/hash.c:268
ext4fs_dirhash+0x246/0x2d0 fs/ext4/hash.c:322
htree_dirblock_to_tree+0x821/0xc90 fs/ext4/namei.c:1124
ext4_htree_fill_tree+0x32d/0xc40 fs/ext4/namei.c:1219
ext4_dx_readdir fs/ext4/dir.c:597 [inline]
ext4_readdir+0x1d2d/0x36a0 fs/ext4/dir.c:142
iterate_dir+0x1f4/0x5c0 fs/readdir.c:106
ovl_dir_read fs/overlayfs/readdir.c:315 [inline]
ovl_indexdir_cleanup+0x2e2/0x940 fs/overlayfs/readdir.c:1183
ovl_get_indexdir fs/overlayfs/super.c:887 [inline]
ovl_fill_super+0x414d/0x6560 fs/overlayfs/super.c:1404
vfs_get_super fs/super.c:1338 [inline]
get_tree_nodev+0xda/0x190 fs/super.c:1357
vfs_get_tree+0x93/0x380 fs/super.c:1771
do_new_mount fs/namespace.c:3337 [inline]
path_mount+0x679/0x1e40 fs/namespace.c:3664
do_mount fs/namespace.c:3677 [inline]
__do_sys_mount fs/namespace.c:3886 [inline]
__se_sys_mount fs/namespace.c:3863 [inline]
__x64_sys_mount+0x287/0x310 fs/namespace.c:3863
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x43/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x6f/0x77
RIP: 0033:0x7ff63aa8fd6d
Code: c3 e8 97 2b 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff63b86f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff63abcc120 RCX: 00007ff63aa8fd6d
RDX: 0000000020000000 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 00007ff63aaf14cd R08: 0000000020000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007ff63abcc120 R15: 00007ff63b84f000
</TASK>
Thank you for taking the time to read this email and we look forward to working with you further.