Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller [off-list ref]:

On Thu, 17 Feb 2022 09:43:03 +0800 you wrote:

When a 6pack device is detaching, the sixpack_close() will act to cleanup
necessary resources. Although del_timer_sync() in sixpack_close()
won't return if there is an active timer, one could use mod_timer() in
sp_xmit_on_air() to wake up timer again by calling userspace syscall such
as ax25_sendmsg(), ax25_connect() and ax25_ioctl().

This unexpected waked handler, sp_xmit_on_air(), realizes nothing about
the undergoing cleanup and may still call pty_write() to use driver layer
resources that have already been released.

[...]

Here is the summary with links:
  - [V3] drivers: hamradio: 6pack: fix UAF bug caused by mod_timer()
    https://git.kernel.org/netdev/net/c/efe4186e6a1b

You are awesome, thank you!
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