Re: [PATCH] net-sysfs: Fix mem leak in netdev_register_kobject

[David Miller]

From: Yue Haibing <yuehaibing@xxxxxxxxxx>
Date: Sat, 2 Mar 2019 10:34:55 +0800

> From: YueHaibing <yuehaibing@xxxxxxxxxx>
> 
> syzkaller report this:
> BUG: memory leak
> unreferenced object 0xffff88837a71a500 (size 256):
>   comm "syz-executor.2", pid 9770, jiffies 4297825125 (age 17.843s)
>   hex dump (first 32 bytes):
>     00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
>     ff ff ff ff ff ff ff ff 20 c0 ef 86 ff ff ff ff  ........ .......
>   backtrace:
>     [<00000000db12624b>] netdev_register_kobject+0x124/0x2e0 net/core/net-sysfs.c:1751
>     [<00000000dc49a994>] register_netdevice+0xcc1/0x1270 net/core/dev.c:8516
>     [<00000000e5f3fea0>] tun_set_iff drivers/net/tun.c:2649 [inline]
>     [<00000000e5f3fea0>] __tun_chr_ioctl+0x2218/0x3d20 drivers/net/tun.c:2883
>     [<000000001b8ac127>] vfs_ioctl fs/ioctl.c:46 [inline]
>     [<000000001b8ac127>] do_vfs_ioctl+0x1a5/0x10e0 fs/ioctl.c:690
>     [<0000000079b269f8>] ksys_ioctl+0x89/0xa0 fs/ioctl.c:705
>     [<00000000de649beb>] __do_sys_ioctl fs/ioctl.c:712 [inline]
>     [<00000000de649beb>] __se_sys_ioctl fs/ioctl.c:710 [inline]
>     [<00000000de649beb>] __x64_sys_ioctl+0x74/0xb0 fs/ioctl.c:710
>     [<000000007ebded1e>] do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
>     [<00000000db315d36>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
>     [<00000000115be9bb>] 0xffffffffffffffff
> 
> It should call kset_unregister to free 'dev->queues_kset'
> in error path of register_queue_kobjects, otherwise will cause a mem leak.
> 
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>

Wow, what an ancient bug.

Applied and queued up for -stable, thanks.