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| author | Misono Tomohiro <misono.tomohiro@jp.fujitsu.com> | 2021-01-27 21:24:56 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-04 11:37:26 +0100 |
| commit | ad71e4decf494cc34f2b8ec6f68c8d71f1548bc3 (patch) | |
| tree | 05684cf678198575e6c45e202afd4ebfdd823488 | |
| parent | 56ef08902f0dcc77a28e0c75ed28357b3ead074b (diff) | |
| download | kernel_replicant_linux-ad71e4decf494cc34f2b8ec6f68c8d71f1548bc3.tar.gz kernel_replicant_linux-ad71e4decf494cc34f2b8ec6f68c8d71f1548bc3.tar.bz2 kernel_replicant_linux-ad71e4decf494cc34f2b8ec6f68c8d71f1548bc3.zip | |
x86/MSR: Filter MSR writes through X86_IOC_WRMSR_REGS ioctl too
[ Upstream commit 02a16aa13574c8526beadfc9ae8cc9b66315fa2d ]
Commit
a7e1f67ed29f ("x86/msr: Filter MSR writes")
introduced a module parameter to disable writing to the MSR device file
and tainted the kernel upon writing. As MSR registers can be written by
the X86_IOC_WRMSR_REGS ioctl too, the same filtering and tainting should
be applied to the ioctl as well.
[ bp: Massage commit message and space out statements. ]
Fixes: a7e1f67ed29f ("x86/msr: Filter MSR writes")
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210127122456.13939-1-misono.tomohiro@jp.fujitsu.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/x86/kernel/msr.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index c0d409810658..79f900ffde4c 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -184,6 +184,13 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg) err = security_locked_down(LOCKDOWN_MSR); if (err) break; + + err = filter_write(regs[1]); + if (err) + return err; + + add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK); + err = wrmsr_safe_regs_on_cpu(cpu, regs); if (err) break; |