# git rev-parse -q --verify 7685cf1a7140d1cd184e43c747012fa14cb3dd14^{commit} 7685cf1a7140d1cd184e43c747012fa14cb3dd14 already have revision, skipping fetch # git checkout -q -f -B kisskb 7685cf1a7140d1cd184e43c747012fa14cb3dd14 # git clean -qxdf # < git log -1 # commit 7685cf1a7140d1cd184e43c747012fa14cb3dd14 # Author: Alexey Kardashevskiy # Date: Wed Jul 11 21:00:44 2018 +1000 # # KVM: PPC: Check if IOMMU page is contained in the pinned physical page # # A VM which has: # - a DMA capable device passed through to it (eg. network card); # - running a malicious kernel that ignores H_PUT_TCE failure; # - capability of using IOMMU pages bigger that physical pages # can create an IOMMU mapping that exposes (for example) 16MB of # the host physical memory to the device when only 64K was allocated to the VM. # # The remaining 16MB - 64K will be some other content of host memory, possibly # including pages of the VM, but also pages of host kernel memory, host # programs or other VMs. # # The attacking VM does not control the location of the page it can map, # and is only allowed to map as many pages as it has pages of RAM. # # We already have a check in drivers/vfio/vfio_iommu_spapr_tce.c that # an IOMMU page is contained in the physical page so the PCI hardware won't # get access to unassigned host memory; however this check is missing in # the KVM fastpath (H_PUT_TCE accelerated code). We were lucky so far and # did not hit this yet as the very first time when the mapping happens # we do not have tbl::it_userspace allocated yet and fall back to # the userspace which in turn calls VFIO IOMMU driver, this fails and # the guest does not retry, # # This stores the smallest preregistered page size in the preregistered # region descriptor and changes the mm_iommu_xxx API to check this against # the IOMMU page size. # # This calculates maximum page size as a minimum of the natural region # alignment and compound page size. For the page shift this uses the shift # returned by find_linux_pte() which indicates how the page is mapped to # the current userspace - if the page is huge and this is not a zero, then # it is a leaf pte and the page is mapped within the range. # # Signed-off-by: Alexey Kardashevskiy # Reviewed-by: Nicholas Piggin # Reviewed-by: David Gibson # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/gcc-5.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < git log --format=%s --max-count=1 7685cf1a7140d1cd184e43c747012fa14cb3dd14 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc83xx_defconfig_powerpc-5.3 CROSS_COMPILE=/opt/cross/kisskb/gcc-5.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux- mpc83xx_defconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc83xx_defconfig_powerpc-5.3 CROSS_COMPILE=/opt/cross/kisskb/gcc-5.3.0-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter. /kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter. arch/powerpc/boot/mpc832x_rdb.dtb: Warning (interrupts_property): /qe@e0100000/mdio@3120/ethernet-phy@0:#interrupt-cells: size is (4), expected multiple of 8 arch/powerpc/boot/mpc832x_rdb.dtb: Warning (interrupts_property): /qe@e0100000/mdio@3120/ethernet-phy@4:#interrupt-cells: size is (4), expected multiple of 8 INFO: Uncompressed kernel (size 0x607758) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x700000) INFO: Uncompressed kernel (size 0x607758) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x700000) INFO: Uncompressed kernel (size 0x607758) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x700000) INFO: Uncompressed kernel (size 0x607758) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x700000) INFO: Uncompressed kernel (size 0x607758) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x700000) INFO: Uncompressed kernel (size 0x607758) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x700000) INFO: Uncompressed kernel (size 0x5f7040) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x607758) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x700000) Image Name: Linux-4.18.0-rc3-g7685cf1 Created: Tue Jul 17 02:38:12 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3060959 Bytes = 2989.22 kB = 2.92 MB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-4.18.0-rc3-g7685cf1 Created: Tue Jul 17 02:38:12 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3084754 Bytes = 3012.46 kB = 2.94 MB Load Address: 00700000 Entry Point: 007001f4 Image Name: Linux-4.18.0-rc3-g7685cf1 Created: Tue Jul 17 02:38:13 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3084989 Bytes = 3012.68 kB = 2.94 MB Load Address: 00700000 Entry Point: 007001f4 Image Name: Linux-4.18.0-rc3-g7685cf1 Created: Tue Jul 17 02:38:13 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3084916 Bytes = 3012.61 kB = 2.94 MB Load Address: 00700000 Entry Point: 007001f4 Image Name: Linux-4.18.0-rc3-g7685cf1 Created: Tue Jul 17 02:38:13 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3084430 Bytes = 3012.14 kB = 2.94 MB Load Address: 00700000 Entry Point: 007001f4 Image Name: Linux-4.18.0-rc3-g7685cf1 Created: Tue Jul 17 02:38:13 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3084962 Bytes = 3012.66 kB = 2.94 MB Load Address: 00700000 Entry Point: 007001f4 Image Name: Linux-4.18.0-rc3-g7685cf1 Created: Tue Jul 17 02:38:13 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3085333 Bytes = 3013.02 kB = 2.94 MB Load Address: 00700000 Entry Point: 007001f4 Completed OK # rm -rf /kisskb/build/powerpc-fixes_mpc83xx_defconfig_powerpc-5.3 # Build took: 0:00:56.082350