# git rev-parse -q --verify 7e1ed4da4a16e035a76001461fbd75c453b73206^{commit} 7e1ed4da4a16e035a76001461fbd75c453b73206 already have revision, skipping fetch # git checkout -q -f -B kisskb 7e1ed4da4a16e035a76001461fbd75c453b73206 # git clean -qxdf # < git log -1 # commit 7e1ed4da4a16e035a76001461fbd75c453b73206 # Author: Breno Leitao # Date: Wed Jan 30 10:46:00 2019 -0200 # # powerpc/ptrace: Mitigate potential Spectre v1 # # 'regno' is directly controlled by user space, hence leading to a potential # exploitation of the Spectre variant 1 vulnerability. # # On PTRACE_SETREGS and PTRACE_GETREGS requests, user space passes the # register number that would be read or written. This register number is # called 'regno' which is part of the 'addr' syscall parameter. # # This 'regno' value is checked against the maximum pt_regs structure size, # and then used to dereference it, which matches the initial part of a # Spectre v1 (and Spectre v1.1) attack. The dereferenced value, then, # is returned to userspace in the GETREGS case. # # This patch sanitizes 'regno' before using it to dereference pt_reg. # # Notice that given that speculation windows are large, the policy is # to kill the speculation on the first load and not worry if it can be # completed with a dependent load/store [1]. # # [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 # # Signed-off-by: Breno Leitao # Acked-by: Gustavo A. R. Silva # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 7e1ed4da4a16e035a76001461fbd75c453b73206 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_randconfig+ppc64le_ppc64le-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- randconfig KCONFIG_SEED=0xA52BCA05 # Added to kconfig CONFIG_STANDALONE=y # Added to kconfig CONFIG_BUILD_DOCSRC=n # Added to kconfig CONFIG_MODULE_SIG=n # Added to kconfig CONFIG_CPU_BIG_ENDIAN=n # Added to kconfig CONFIG_CPU_LITTLE_ENDIAN=y # Added to kconfig CONFIG_PPC64=y # Added to kconfig CONFIG_PPC_BOOK3E_64=n # Added to kconfig CONFIG_PPC_BOOK3S_64=y # Added to kconfig CONFIG_PPC_DISABLE_WERROR=y # Added to kconfig CONFIG_SECTION_MISMATCH_WARN_ONLY=y # Added to kconfig CONFIG_PREVENT_FIRMWARE_BUILD=y # Added to kconfig CONFIG_LD_HEAD_STUB_CATCH=y # yes \n | make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_randconfig+ppc64le_ppc64le-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- oldconfig yes: standard output: Broken pipe # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_randconfig+ppc64le_ppc64le-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/fs/jffs2/xattr.c: In function 'jffs2_build_xattr_subsystem': /kisskb/src/fs/jffs2/xattr.c:887:1: warning: the frame size of 1072 bytes is larger than 1024 bytes [-Wframe-larger-than=] } ^ WARNING: vmlinux.o(.text+0x2cb4): Section mismatch in reference from the variable __boot_from_prom to the function .init.text:prom_init() The function __boot_from_prom() references the function __init prom_init(). This is often because __boot_from_prom lacks a __init annotation or the annotation of prom_init is wrong. WARNING: vmlinux.o(.text+0x2f44): Section mismatch in reference from the variable start_here_multiplatform to the function .init.text:early_setup() The function start_here_multiplatform() references the function __init early_setup(). This is often because start_here_multiplatform lacks a __init annotation or the annotation of early_setup is wrong. WARNING: vmlinux.o(.text+0x2f78): Section mismatch in reference from the variable start_here_common to the function .init.text:start_kernel() The function start_here_common() references the function __init start_kernel(). This is often because start_here_common lacks a __init annotation or the annotation of start_kernel is wrong. Completed OK # rm -rf /kisskb/build/powerpc-next-rand_randconfig+ppc64le_ppc64le-gcc5 # Build took: 0:04:46.611558