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| author | Andy Lutomirski <luto@kernel.org> | 2015-09-20 16:32:05 -0700 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-10-27 22:14:57 -0400 |
| commit | a70046a8f849fb1a98c5aee0c3504ddf61461eab (patch) | |
| tree | ac2544692b3ebdbada055e768807df84b0578cc2 /lib/mpi/mpi-cmp.c | |
| parent | c735802ffff335a033b1fba5efd26d778d7b43d6 (diff) | |
x86/nmi/64: Fix a paravirt stack-clobbering bug in the NMI code
[ Upstream commit 83c133cf11fb0e68a51681447e372489f052d40e ]
The NMI entry code that switches to the normal kernel stack needs to
be very careful not to clobber any extra stack slots on the NMI
stack. The code is fine under the assumption that SWAPGS is just a
normal instruction, but that assumption isn't really true. Use
SWAPGS_UNSAFE_STACK instead.
This is part of a fix for some random crashes that Sasha saw.
Fixes: 9b6e6a8334d5 ("x86/nmi/64: Switch stacks on userspace NMI entry")
Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/974bc40edffdb5c2950a5c4977f821a446b76178.1442791737.git.luto@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'lib/mpi/mpi-cmp.c')
0 files changed, 0 insertions, 0 deletions