This is a note to let you know that I've just added the patch titled acpi/nfit, x86/mce: Validate a MCE's address before using it to the 4.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=s... The filename of the patch is: acpi-nfit-x86-mce-validate-a-mce-s-address-before-using-it.patch and it can be found in the queue-4.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org&gt; know about it. From: Vishal Verma <vishal.l.verma(a)intel.com&gt; Date: Thu, 25 Oct 2018 18:37:29 -0600 Subject: acpi/nfit, x86/mce: Validate a MCE's address before using it From: Vishal Verma <vishal.l.verma(a)intel.com&gt; 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 <elliott(a)hpe.com&gt; Signed-off-by: Vishal Verma <vishal.l.verma(a)intel.com&gt; Signed-off-by: Borislav Petkov <bp(a)suse.de&gt; CC: Arnd Bergmann <arnd(a)arndb.de&gt; Cc: Dan Williams <dan.j.williams(a)intel.com&gt; CC: Dave Jiang <dave.jiang(a)intel.com&gt; CC: elliott(a)hpe.com CC: "H. Peter Anvin" <hpa(a)zytor.com&gt; CC: Ingo Molnar <mingo(a)redhat.com&gt; CC: Len Brown <lenb(a)kernel.org&gt; CC: linux-acpi(a)vger.kernel.org CC: linux-edac <linux-edac(a)vger.kernel.org&gt; CC: linux-nvdimm(a)lists.01.org CC: Qiuxu Zhuo <qiuxu.zhuo(a)intel.com&gt; CC: "Rafael J. Wysocki" <rjw(a)rjwysocki.net&gt; CC: Ross Zwisler <zwisler(a)kernel.org&gt; CC: stable <stable(a)vger.kernel.org&gt; CC: Thomas Gleixner <tglx(a)linutronix.de&gt; CC: Tony Luck <tony.luck(a)intel.com&gt; CC: x86-ml <x86(a)kernel.org&gt; CC: Yazen Ghannam <yazen.ghannam(a)amd.com&gt; Link: http://lkml.kernel.org/r/20181026003729.8420-2-vishal.l.verma@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org&gt; --- 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(-) --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -217,6 +217,7 @@ static inline int umc_normaddr_to_sysadd 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); --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -489,7 +489,7 @@ static void mce_report_event(struct pt_r * 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; @@ -509,6 +509,7 @@ static int mce_usable_address(struct mce return 1; } +EXPORT_SYMBOL_GPL(mce_usable_address); bool mce_is_memory_error(struct mce *m) { --- a/drivers/acpi/nfit/mce.c +++ b/drivers/acpi/nfit/mce.c @@ -29,6 +29,10 @@ static int nfit_handle_mce(struct notifi 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 Patches currently in stable-queue which might be from vishal.l.verma(a)intel.com are queue-4.18/acpi-nfit-x86-mce-validate-a-mce-s-address-before-using-it.patch queue-4.18/acpi-nfit-x86-mce-handle-only-uncorrectable-machine-checks.patch