Thomas Gleixner 43be46e896 x86/fpu: Sanitize xstateregs_set() ... xstateregs_set() operates on a stopped task and tries to copy the provided buffer into the task's fpu.state.xsave buffer. Any error while copying or invalid state detected after copying results in wiping the target task's FPU state completely including supervisor states. That's just wrong. The caller supplied invalid data or has a problem with unmapped memory, so there is absolutely no justification to corrupt the target state. Fix this with the following modifications: 1) If data has to be copied from userspace, allocate a buffer and copy from user first. 2) Use copy_kernel_to_xstate() unconditionally so that header checking works correctly. 3) Return on error without corrupting the target state. This prevents corrupting states and lets the caller deal with the problem it caused in the first place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.214903673@linutronix.de		2021-06-23 17:49:46 +02:00
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asm	x86/fpu: Sanitize xstateregs_set()	2021-06-23 17:49:46 +02:00
uapi/asm	x86/elf: Support a new ELF aux vector AT_MINSIGSTKSZ	2021-05-19 12:18:45 +02:00