Messages in this thread | | | From | Anton Volkov <> | Subject | Possible race in pc87413_wdt.ko | Date | Mon, 7 Aug 2017 16:22:17 +0300 |
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Hello.
While searching for races in the Linux kernel I've come across "drivers/watchdog/pc87413_wdt.ko" module. Here is a question that I came up with while analyzing results. Lines are given using the info from Linux v4.12.
Consider the following case:
Thread 1: Thread 2: pc87413_init misc_register(&pc87413_miscdev) -> pc87413_get_swc_base_addr pc87413_open -> pc87413_refresh -> pc87413_swc_bank3 swc_base_addr = ... <read access to swc_base_addr> (pc87413_wdt.c: line 133) (pc87413_wdt.c: line 146)
So in this case preemptive registration of the device leads to a possibility of race between the initialization process and a callback to the registered device.
Is this race feasible from your point of view? And if it is, is it possible to move the device registration a bit further down in the pc87413_init function?
Thank you for your time.
-- Anton Volkov Linux Verification Center, ISPRAS web: http://linuxtesting.org e-mail: avolkov@ispras.ru
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