[syzbot] [fscrypt?] [f2fs?] memory leak in fscrypt_setup_filename

[syzbot] [fscrypt?] [f2fs?] memory leak in fscrypt_setup_filename

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    af4e9ef3d784 uaccess: Fix scoped_user_read_access() for 'p..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12506d5a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2c6ad6fefffa76b1
dashboard link: https://syzkaller.appspot.com/bug?extid=cf7946ab25b21abc4b66
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=160a18d6580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14e2b0ba580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/70cb2ebe1e6e/disk-af4e9ef3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/945fea3c8a6d/vmlinux-af4e9ef3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fa6a6a5cbcc8/bzImage-af4e9ef3.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/c12ae92fa9b6/mount_0.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=10e1d202580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cf7946ab25b21abc4b66@syzkaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff888127f70830 (size 16):
  comm "syz.0.23", pid 6144, jiffies 4294943712
  hex dump (first 16 bytes):
    3c af 57 72 5b e6 8f ad 6e 8e fd 33 42 39 03 ff  <.Wr[...n..3B9..
  backtrace (crc 925f8a80):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4520 [inline]
    slab_alloc_node mm/slub.c:4844 [inline]
    __do_kmalloc_node mm/slub.c:5237 [inline]
    __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5250
    kmalloc_noprof include/linux/slab.h:954 [inline]
    fscrypt_setup_filename+0x15e/0x3b0 fs/crypto/fname.c:364
    f2fs_setup_filename+0x52/0xb0 fs/f2fs/dir.c:143
    f2fs_rename+0x159/0xca0 fs/f2fs/namei.c:961
    f2fs_rename2+0xd5/0xf20 fs/f2fs/namei.c:1308
    vfs_rename+0x7ff/0x1250 fs/namei.c:6026
    filename_renameat2+0x4f4/0x660 fs/namei.c:6144
    __do_sys_renameat2 fs/namei.c:6173 [inline]
    __se_sys_renameat2 fs/namei.c:6168 [inline]
    __x64_sys_renameat2+0x59/0x80 fs/namei.c:6168
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [fscrypt?] [f2fs?] memory leak in fscrypt_setup_filename

[Eric Biggers]

On Tue, Mar 03, 2026 at 02:25:37PM -0800, syzbot wrote:
> BUG: memory leak
> unreferenced object 0xffff888127f70830 (size 16):
>   comm "syz.0.23", pid 6144, jiffies 4294943712
>   hex dump (first 16 bytes):
>     3c af 57 72 5b e6 8f ad 6e 8e fd 33 42 39 03 ff  <.Wr[...n..3B9..
>   backtrace (crc 925f8a80):
>     kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>     slab_post_alloc_hook mm/slub.c:4520 [inline]
>     slab_alloc_node mm/slub.c:4844 [inline]
>     __do_kmalloc_node mm/slub.c:5237 [inline]
>     __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5250
>     kmalloc_noprof include/linux/slab.h:954 [inline]
>     fscrypt_setup_filename+0x15e/0x3b0 fs/crypto/fname.c:364
>     f2fs_setup_filename+0x52/0xb0 fs/f2fs/dir.c:143
>     f2fs_rename+0x159/0xca0 fs/f2fs/namei.c:961
>     f2fs_rename2+0xd5/0xf20 fs/f2fs/namei.c:1308

The following commit added a call to f2fs_setup_filename() without a
matching call to f2fs_free_filename():

    commit 40b2d55e045222dd6de2a54a299f682e0f954b03
    Author: Chao Yu <chao@kernel.org>
    Date:   Wed Feb 7 15:05:48 2024 +0800

        f2fs: fix to create selinux label during whiteout initialization

Chao, do you want to handle fixing this?

- Eric

Re: [syzbot] [fscrypt?] [f2fs?] memory leak in fscrypt_setup_filename

[Chao Yu]

On 2026/3/4 08:35, Eric Biggers wrote:
> On Tue, Mar 03, 2026 at 02:25:37PM -0800, syzbot wrote:
>> BUG: memory leak
>> unreferenced object 0xffff888127f70830 (size 16):
>>    comm "syz.0.23", pid 6144, jiffies 4294943712
>>    hex dump (first 16 bytes):
>>      3c af 57 72 5b e6 8f ad 6e 8e fd 33 42 39 03 ff  <.Wr[...n..3B9..
>>    backtrace (crc 925f8a80):
>>      kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>>      slab_post_alloc_hook mm/slub.c:4520 [inline]
>>      slab_alloc_node mm/slub.c:4844 [inline]
>>      __do_kmalloc_node mm/slub.c:5237 [inline]
>>      __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5250
>>      kmalloc_noprof include/linux/slab.h:954 [inline]
>>      fscrypt_setup_filename+0x15e/0x3b0 fs/crypto/fname.c:364
>>      f2fs_setup_filename+0x52/0xb0 fs/f2fs/dir.c:143
>>      f2fs_rename+0x159/0xca0 fs/f2fs/namei.c:961
>>      f2fs_rename2+0xd5/0xf20 fs/f2fs/namei.c:1308
> 
> The following commit added a call to f2fs_setup_filename() without a
> matching call to f2fs_free_filename():
> 
>      commit 40b2d55e045222dd6de2a54a299f682e0f954b03
>      Author: Chao Yu <chao@kernel.org>
>      Date:   Wed Feb 7 15:05:48 2024 +0800
> 
>          f2fs: fix to create selinux label during whiteout initialization
> 
> Chao, do you want to handle fixing this?

Oh, my bad, let me fix this ASAP.

Thanks Eric for the reminder.

Thanks,

> 
> - Eric

Re: [syzbot] [fscrypt?] [f2fs?] memory leak in fscrypt_setup_filename

[Chao Yu]

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot

On 2026/3/4 06:25, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    af4e9ef3d784 uaccess: Fix scoped_user_read_access() for 'p..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=12506d5a580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2c6ad6fefffa76b1
> dashboard link: https://syzkaller.appspot.com/bug?extid=cf7946ab25b21abc4b66
> compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=160a18d6580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14e2b0ba580000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/70cb2ebe1e6e/disk-af4e9ef3.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/945fea3c8a6d/vmlinux-af4e9ef3.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/fa6a6a5cbcc8/bzImage-af4e9ef3.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/c12ae92fa9b6/mount_0.gz
>    fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=10e1d202580000)
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+cf7946ab25b21abc4b66@syzkaller.appspotmail.com
> 
> BUG: memory leak
> unreferenced object 0xffff888127f70830 (size 16):
>    comm "syz.0.23", pid 6144, jiffies 4294943712
>    hex dump (first 16 bytes):
>      3c af 57 72 5b e6 8f ad 6e 8e fd 33 42 39 03 ff  <.Wr[...n..3B9..
>    backtrace (crc 925f8a80):
>      kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
>      slab_post_alloc_hook mm/slub.c:4520 [inline]
>      slab_alloc_node mm/slub.c:4844 [inline]
>      __do_kmalloc_node mm/slub.c:5237 [inline]
>      __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5250
>      kmalloc_noprof include/linux/slab.h:954 [inline]
>      fscrypt_setup_filename+0x15e/0x3b0 fs/crypto/fname.c:364
>      f2fs_setup_filename+0x52/0xb0 fs/f2fs/dir.c:143
>      f2fs_rename+0x159/0xca0 fs/f2fs/namei.c:961
>      f2fs_rename2+0xd5/0xf20 fs/f2fs/namei.c:1308
>      vfs_rename+0x7ff/0x1250 fs/namei.c:6026
>      filename_renameat2+0x4f4/0x660 fs/namei.c:6144
>      __do_sys_renameat2 fs/namei.c:6173 [inline]
>      __se_sys_renameat2 fs/namei.c:6168 [inline]
>      __x64_sys_renameat2+0x59/0x80 fs/namei.c:6168
>      do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>      do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
>      entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
> 
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
> 
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
> 
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
> 
> If you want to undo deduplication, reply with:
> #syz undup

Re: [syzbot] [fscrypt?] [f2fs?] memory leak in fscrypt_setup_filename

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+cf7946ab25b21abc4b66@syzkaller.appspotmail.com
Tested-by: syzbot+cf7946ab25b21abc4b66@syzkaller.appspotmail.com

Tested on:

commit:         be41931c f2fs: fix to avoid memory leak in f2fs_rename()
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/syzbot
console output: https://syzkaller.appspot.com/x/log.txt?x=135fb006580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9d985797319d4da8
dashboard link: https://syzkaller.appspot.com/bug?extid=cf7946ab25b21abc4b66
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.