CVE-2021-47357 Information

Description

In the Linux kernel the following vulnerability has been resolved:

atm: iphase: fix possible use-after-free in ia_module_exit()

This module’s remove path calls del_timer(). However that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver’s remove function has finished which would result in a use-after-free.

Fix by calling del_timer_sync() which makes sure the timer handler has finished and unable to re-schedule itself.

Reference

https://git.kernel.org/stable/c/9e161687855175334ca93c6c3ccb221731194479 https://git.kernel.org/stable/c/a832ee2f2145f57443b2d565f8cb5490e8339f42 https://git.kernel.org/stable/c/bcdd2be48edd8c6867fb44112cb8d18086beae29 https://git.kernel.org/stable/c/89ce0b0747f319eb70f85bc820dcc43cebbd5417 https://git.kernel.org/stable/c/c9172498d4d62c9b64e5fb37c1ee0343e65fe51b https://git.kernel.org/stable/c/e759ff76ebbbfcdcf83b6634c54dc47828573d8b https://git.kernel.org/stable/c/b58d246a058ae88484758cd4ab27b3180fd5ecf8 https://git.kernel.org/stable/c/d1fb12412874c94ad037e11d0ecdd1140a439297 https://git.kernel.org/stable/c/1c72e6ab66b9598cac741ed397438a52065a8f1f