Commits
![Francesco Ruggeri](https://secure.gravatar.com/avatar/e8bc8de67a96f586b35f3270e6555b68.jpg?s=96&d=mm)
Francesco Ruggeri committed b8b5c898b00
ACPI: OSL: only free map once in osl.c commit 833a426cc471b6088011b3d67f1dc4e147614647 upstream. 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> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>