Messages in this thread | | | From | Dmitry Safonov <> | Date | Thu, 21 Nov 2019 22:58:21 +0000 | Subject | Re: [PATCH] ACPI: only free map once in osl.c |
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On Wed, 20 Nov 2019 at 05:50, Francesco Ruggeri <fruggeri@arista.com> wrote: > > acpi_os_map_cleanup checks map->refcount outside of acpi_ioremap_lock > before freeing the map. This creates a race condition the can result > in the map being freed more than once. > A panic can be caused by running > > for ((i=0; i<10; i++)) > do > for ((j=0; j<100000; j++)) > do > cat /sys/firmware/acpi/tables/data/BERT >/dev/null > done & > done > > This patch makes sure that only the process that drops the reference > to 0 does the freeing. > > Fixes: b7c1fadd6c2e ("ACPI: Do not use krefs under a mutex in osl.c") > Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Thanks, Dmitry
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