From 8c54762464516cb7e6b0adee0ae192a508554b5f Mon Sep 17 00:00:00 2001 From: Vishal Verma Date: Thu, 25 Oct 2018 18:37:29 -0600 Subject: [PATCH] acpi/nfit, x86/mce: Validate a MCE's address before using it commit e8a308e5f47e545e0d41d0686c00f5f5217c5f61 upstream. The NFIT machine check handler uses the physical address from the mce structure, and compares it against information in the ACPI NFIT table to determine whether that location lies on an NVDIMM. The mce->addr field however may not always be valid, and this is indicated by the MCI_STATUS_ADDRV bit in the status field. Export mce_usable_address() which already performs validation for the address, and use it in the NFIT handler. Fixes: 6839a6d96f4e ("nfit: do an ARS scrub on hitting a latent media error") Reported-by: Robert Elliott Signed-off-by: Vishal Verma Signed-off-by: Borislav Petkov CC: Arnd Bergmann Cc: Dan Williams CC: Dave Jiang CC: elliott@hpe.com CC: "H. Peter Anvin" CC: Ingo Molnar CC: Len Brown CC: linux-acpi@vger.kernel.org CC: linux-edac CC: linux-nvdimm@lists.01.org CC: Qiuxu Zhuo CC: "Rafael J. Wysocki" CC: Ross Zwisler CC: stable CC: Thomas Gleixner CC: Tony Luck CC: x86-ml CC: Yazen Ghannam Link: http://lkml.kernel.org/r/20181026003729.8420-2-vishal.l.verma@intel.com Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/mce.h | 1 + arch/x86/kernel/cpu/mcheck/mce.c | 3 ++- drivers/acpi/nfit/mce.c | 4 ++++ 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 3111b3c..eb786f9 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -217,6 +217,7 @@ static inline int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8 umc, u64 *s int mce_available(struct cpuinfo_x86 *c); bool mce_is_memory_error(struct mce *m); bool mce_is_correctable(struct mce *m); +int mce_usable_address(struct mce *m); DECLARE_PER_CPU(unsigned, mce_exception_count); DECLARE_PER_CPU(unsigned, mce_poll_count); diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 2701594..cdbedeb 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -485,7 +485,7 @@ static void mce_report_event(struct pt_regs *regs) * be somewhat complicated (e.g. segment offset would require an instruction * parser). So only support physical addresses up to page granuality for now. */ -static int mce_usable_address(struct mce *m) +int mce_usable_address(struct mce *m) { if (!(m->status & MCI_STATUS_ADDRV)) return 0; @@ -505,6 +505,7 @@ static int mce_usable_address(struct mce *m) return 1; } +EXPORT_SYMBOL_GPL(mce_usable_address); bool mce_is_memory_error(struct mce *m) { diff --git a/drivers/acpi/nfit/mce.c b/drivers/acpi/nfit/mce.c index 7a51707..d6c1b10 100644 --- a/drivers/acpi/nfit/mce.c +++ b/drivers/acpi/nfit/mce.c @@ -29,6 +29,10 @@ static int nfit_handle_mce(struct notifier_block *nb, unsigned long val, if (!mce_is_memory_error(mce) || mce_is_correctable(mce)) return NOTIFY_DONE; + /* Verify the address reported in the MCE is valid. */ + if (!mce_usable_address(mce)) + return NOTIFY_DONE; + /* * mce->addr contains the physical addr accessed that caused the * machine check. We need to walk through the list of NFITs, and see -- 2.7.4