Re: [syzbot] memory leak in nilfs_sysfs_create_device_group

[Ryusuke Konishi]

On Wed, Oct 5, 2022 at 5:44 PM syzbot wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    a5088ee7251e Merge tag 'thermal-6.1-rc1' of git://git.kern..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=153f2492880000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=21254cf9c7c084e0
> dashboard link: https://syzkaller.appspot.com/bug?extid=2e2f697dbd0f429d5dae
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1556a368880000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/c2d2c6d22fae/disk-a5088ee7.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/3c66d2393267/vmlinux-a5088ee7.xz
> mounted in repro: https://storage.googleapis.com/syzbot-assets/f2050cc3fa6c/mount_0.gz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+2e2f697dbd0f429d5dae@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> BUG: memory leak
> unreferenced object 0xffff888119526520 (size 32):
>   comm "syz-executor.4", pid 4168, jiffies 4294949450 (age 9.260s)
>   hex dump (first 32 bytes):
>     6c 6f 6f 70 34 00 00 00 00 00 00 00 00 00 00 00  loop4...........
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace:
>     [<ffffffff814c5b86>] kstrdup+0x36/0x70 mm/util.c:61
>     [<ffffffff814c5c13>] kstrdup_const+0x53/0x80 mm/util.c:84
>     [<ffffffff823af0e2>] kvasprintf_const+0xc2/0x110 lib/kasprintf.c:48
>     [<ffffffff824a442b>] kobject_set_name_vargs+0x3b/0xe0 lib/kobject.c:257
>     [<ffffffff824a48ad>] kobject_add_varg lib/kobject.c:352 [inline]
>     [<ffffffff824a48ad>] kobject_init_and_add+0x6d/0xc0 lib/kobject.c:441
>     [<ffffffff81e217ba>] nilfs_sysfs_create_device_group+0x9a/0x3d0 fs/nilfs2/sysfs.c:991
>     [<ffffffff81e0a03c>] init_nilfs+0x51c/0x680 fs/nilfs2/the_nilfs.c:637
>     [<ffffffff81df608b>] nilfs_fill_super fs/nilfs2/super.c:1047 [inline]
>     [<ffffffff81df608b>] nilfs_mount+0x51b/0x890 fs/nilfs2/super.c:1317
>     [<ffffffff8164f4ab>] legacy_get_tree+0x2b/0x90 fs/fs_context.c:610
>     [<ffffffff815e8c48>] vfs_get_tree+0x28/0x100 fs/super.c:1530
>     [<ffffffff8162cbd7>] do_new_mount fs/namespace.c:3040 [inline]
>     [<ffffffff8162cbd7>] path_mount+0xc37/0x10d0 fs/namespace.c:3370
>     [<ffffffff8162d7be>] do_mount fs/namespace.c:3383 [inline]
>     [<ffffffff8162d7be>] __do_sys_mount fs/namespace.c:3591 [inline]
>     [<ffffffff8162d7be>] __se_sys_mount fs/namespace.c:3568 [inline]
>     [<ffffffff8162d7be>] __x64_sys_mount+0x18e/0x1d0 fs/namespace.c:3568
>     [<ffffffff845ebbf5>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>     [<ffffffff845ebbf5>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
>     [<ffffffff84800087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
>
>
> ---
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>
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#syz dup: memory leak in kobject_set_name_vargs (5)

Looks like the same issue as above.  I'm now digging into it.

Ryusuke Konishi