Re: [PATCH net] ax25: Fix netdev refcount issue

From: patchwork-bot+netdevbpf
Date: Tue Apr 23 2024 - 05:50:38 EST


Hello:

This patch was applied to netdev/net.git (main)
by Paolo Abeni <pabeni@xxxxxxxxxx>:

On Fri, 19 Apr 2024 10:04:56 +0800 you wrote:
> The dev_tracker is added to ax25_cb in ax25_bind(). When the
> ax25 device is detaching, the dev_tracker of ax25_cb should be
> deallocated in ax25_kill_by_device() instead of the dev_tracker
> of ax25_dev. The log reported by ref_tracker is shown below:
>
> [ 80.884935] ref_tracker: reference already released.
> [ 80.885150] ref_tracker: allocated in:
> [ 80.885349] ax25_dev_device_up+0x105/0x540
> [ 80.885730] ax25_device_event+0xa4/0x420
> [ 80.885730] notifier_call_chain+0xc9/0x1e0
> [ 80.885730] __dev_notify_flags+0x138/0x280
> [ 80.885730] dev_change_flags+0xd7/0x180
> [ 80.885730] dev_ifsioc+0x6a9/0xa30
> [ 80.885730] dev_ioctl+0x4d8/0xd90
> [ 80.885730] sock_do_ioctl+0x1c2/0x2d0
> [ 80.885730] sock_ioctl+0x38b/0x4f0
> [ 80.885730] __se_sys_ioctl+0xad/0xf0
> [ 80.885730] do_syscall_64+0xc4/0x1b0
> [ 80.885730] entry_SYSCALL_64_after_hwframe+0x67/0x6f
> [ 80.885730] ref_tracker: freed in:
> [ 80.885730] ax25_device_event+0x272/0x420
> [ 80.885730] notifier_call_chain+0xc9/0x1e0
> [ 80.885730] dev_close_many+0x272/0x370
> [ 80.885730] unregister_netdevice_many_notify+0x3b5/0x1180
> [ 80.885730] unregister_netdev+0xcf/0x120
> [ 80.885730] sixpack_close+0x11f/0x1b0
> [ 80.885730] tty_ldisc_kill+0xcb/0x190
> [ 80.885730] tty_ldisc_hangup+0x338/0x3d0
> [ 80.885730] __tty_hangup+0x504/0x740
> [ 80.885730] tty_release+0x46e/0xd80
> [ 80.885730] __fput+0x37f/0x770
> [ 80.885730] __x64_sys_close+0x7b/0xb0
> [ 80.885730] do_syscall_64+0xc4/0x1b0
> [ 80.885730] entry_SYSCALL_64_after_hwframe+0x67/0x6f
> [ 80.893739] ------------[ cut here ]------------
> [ 80.894030] WARNING: CPU: 2 PID: 140 at lib/ref_tracker.c:255 ref_tracker_free+0x47b/0x6b0
> [ 80.894297] Modules linked in:
> [ 80.894929] CPU: 2 PID: 140 Comm: ax25_conn_rel_6 Not tainted 6.9.0-rc4-g8cd26fd90c1a #11
> [ 80.895190] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qem4
> [ 80.895514] RIP: 0010:ref_tracker_free+0x47b/0x6b0
> [ 80.895808] Code: 83 c5 18 4c 89 eb 48 c1 eb 03 8a 04 13 84 c0 0f 85 df 01 00 00 41 83 7d 00 00 75 4b 4c 89 ff 9
> [ 80.896171] RSP: 0018:ffff888009edf8c0 EFLAGS: 00000286
> [ 80.896339] RAX: 1ffff1100141ac00 RBX: 1ffff1100149463b RCX: dffffc0000000000
> [ 80.896502] RDX: 0000000000000001 RSI: 0000000000000246 RDI: ffff88800a0d6518
> [ 80.896925] RBP: ffff888009edf9b0 R08: ffff88806d3288d3 R09: 1ffff1100da6511a
> [ 80.897212] R10: dffffc0000000000 R11: ffffed100da6511b R12: ffff88800a4a31d4
> [ 80.897859] R13: ffff88800a4a31d8 R14: dffffc0000000000 R15: ffff88800a0d6518
> [ 80.898279] FS: 00007fd88b7fe700(0000) GS:ffff88806d300000(0000) knlGS:0000000000000000
> [ 80.899436] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 80.900181] CR2: 00007fd88c001d48 CR3: 000000000993e000 CR4: 00000000000006f0
> ...
> [ 80.935774] ref_tracker: sp%d@000000000bb9df3d has 1/1 users at
> [ 80.935774] ax25_bind+0x424/0x4e0
> [ 80.935774] __sys_bind+0x1d9/0x270
> [ 80.935774] __x64_sys_bind+0x75/0x80
> [ 80.935774] do_syscall_64+0xc4/0x1b0
> [ 80.935774] entry_SYSCALL_64_after_hwframe+0x67/0x6f
>
> [...]

Here is the summary with links:
- [net] ax25: Fix netdev refcount issue
https://git.kernel.org/netdev/net/c/467324bcfe1a

You are awesome, thank you!
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