Commit acd9910c authored by Yang Zhong's avatar Yang Zhong Committed by Aichun Shi
Browse files

x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation 

mainline inclusion
from mainline-v5.18-rc1
commit 063452fd
category: bugfix
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I590ZC


CVE: NA

Intel-SIG: commit 063452fd x86/fpu/xstate: Fix the ARCH_REQ_XCOMP_PERM implementation.

--------------------------------

ARCH_REQ_XCOMP_PERM is supposed to add the requested feature to the
permission bitmap of thread_group_leader()->fpu. But the code overwrites
the bitmap with the requested feature bit only rather than adding it.

Fix the code to add the requested feature bit to the master bitmask.

Fixes: db8268df ("x86/arch_prctl: Add controls for dynamic XSTATE components")
Signed-off-by: default avatarYang Zhong <yang.zhong@intel.com>
Signed-off-by: default avatarChang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Paolo Bonzini <bonzini@gnu.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220129173647.27981-2-chang.seok.bae@intel.com


Signed-off-by: default avatarLin Wang <lin.x.wang@intel.com>
Signed-off-by: default avatarAichun Shi <aichun.shi@intel.com>
parent 34eeaa4f

arch/x86/kernel/fpu/xstate.c

+1 −1
Original line number Diff line number Diff line
@@ -1626,7 +1626,7 @@ static int __xstate_request_perm(u64 permitted, u64 requested) 
		return ret;



	/* Pairs with the READ_ONCE() in xstate_get_group_perm() */

	WRITE_ONCE(fpu->perm.__state_perm, requested);

	WRITE_ONCE(fpu->perm.__state_perm, mask);

	/* Protected by sighand lock */

	fpu->perm.__state_size = ksize;

	fpu->perm.__user_state_size = usize;