Re: [syzbot] [fs?] memory leak in fasync_helper (2)

[Christian Brauner]

On Wed, Sep 20, 2023 at 11:52:48PM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    f0b0d403eabb Merge tag 'kbuild-fixes-v6.6' of git://git.ke..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=144e498c680000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=943a94479fa8e863
> dashboard link: https://syzkaller.appspot.com/bug?extid=5f1acda7e06a2298fae6
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=161ac702680000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16515418680000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/47695e593bcd/disk-f0b0d403.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/306f9aca0df9/vmlinux-f0b0d403.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/25549b4deb42/bzImage-f0b0d403.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+5f1acda7e06a2298fae6@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> BUG: memory leak
> unreferenced object 0xffff888114ac69c0 (size 48):
>   comm "syz-executor199", pid 5124, jiffies 4294947402 (age 21.830s)
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 01 46 00 00 03 00 00 00  .........F......
>     00 00 00 00 00 00 00 00 00 81 0f 09 81 88 ff ff  ................
>   backtrace:
>     [<ffffffff816b06bd>] fasync_alloc fs/fcntl.c:892 [inline]
>     [<ffffffff816b06bd>] fasync_add_entry fs/fcntl.c:950 [inline]
>     [<ffffffff816b06bd>] fasync_helper+0x3d/0xc0 fs/fcntl.c:979
>     [<ffffffff83e8f2cb>] sock_fasync+0x4b/0xa0 net/socket.c:1427

#syz set subsystems: net