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authorLukasz Odzioba <lukasz.odzioba@intel.com>2016-12-28 14:55:40 +0100
committerIngo Molnar <mingo@kernel.org>2017-01-05 08:54:34 +0100
commitdd853fd216d1485ed3045ff772079cc8689a9a4a (patch)
tree4b351982ec908b819b9f3dff707fc99f1830d910 /arch/xtensa
parente02003b515e8d95f40f20f213622bb82510873d2 (diff)
downloadop-kernel-dev-dd853fd216d1485ed3045ff772079cc8689a9a4a.zip
op-kernel-dev-dd853fd216d1485ed3045ff772079cc8689a9a4a.tar.gz
x86/cpu: Fix bootup crashes by sanitizing the argument of the 'clearcpuid=' command-line option
A negative number can be specified in the cmdline which will be used as setup_clear_cpu_cap() argument. With that we can clear/set some bit in memory predceeding boot_cpu_data/cpu_caps_cleared which may cause kernel to misbehave. This patch adds lower bound check to setup_disablecpuid(). Boris Petkov reproduced a crash: [ 1.234575] BUG: unable to handle kernel paging request at ffffffff858bd540 [ 1.236535] IP: memcpy_erms+0x6/0x10 Signed-off-by: Lukasz Odzioba <lukasz.odzioba@intel.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: andi.kleen@intel.com Cc: bp@alien8.de Cc: dave.hansen@linux.intel.com Cc: luto@kernel.org Cc: slaoub@gmail.com Fixes: ac72e7888a61 ("x86: add generic clearcpuid=... option") Link: http://lkml.kernel.org/r/1482933340-11857-1-git-send-email-lukasz.odzioba@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/xtensa')
0 files changed, 0 insertions, 0 deletions
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