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Aaron TomlinandGreg Kroah-Hartman
15ba8053fe
commit98e37db4a3upstream. This patch addresses a critical memory management flaw. When CONFIG_CPUMASK_OFFSTACK is enabled, cpumask_var_t is a pointer. Consequently, sizeof(new_mask) evaluates to the pointer size, causing copy_from_user() to clobber the mask pointer. Furthermore, the old logic performed copy_from_user() before allocating the mask. Fix this by allocating new_mask first. To handle variable-sized user masks correctly, use cpumask_size() to truncate overly large user masks or pad undersized masks with zeros before copying the data directly into the allocated buffer. Fixes:295cbf6d63("[MIPS] Move FPU affinity code into separate file.") Cc: stable@vger.kernel.org Signed-off-by: Aaron Tomlin <atomlin@atomlin.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>