# git rev-parse -q --verify a8318c13e79badb92bc6640704a64cc022a6eb97^{commit} a8318c13e79badb92bc6640704a64cc022a6eb97 already have revision, skipping fetch # git checkout -q -f -B kisskb a8318c13e79badb92bc6640704a64cc022a6eb97 # git clean -qxdf # < git log -1 # commit a8318c13e79badb92bc6640704a64cc022a6eb97 # Author: Gustavo Romero # Date: Wed Sep 4 00:55:28 2019 -0400 # # powerpc/tm: Fix restoring FP/VMX facility incorrectly on interrupts # # When in userspace and MSR FP=0 the hardware FP state is unrelated to # the current process. This is extended for transactions where if tbegin # is run with FP=0, the hardware checkpoint FP state will also be # unrelated to the current process. Due to this, we need to ensure this # hardware checkpoint is updated with the correct state before we enable # FP for this process. # # Unfortunately we get this wrong when returning to a process from a # hardware interrupt. A process that starts a transaction with FP=0 can # take an interrupt. When the kernel returns back to that process, we # change to FP=1 but with hardware checkpoint FP state not updated. If # this transaction is then rolled back, the FP registers now contain the # wrong state. # # The process looks like this: # Userspace: Kernel # # Start userspace # with MSR FP=0 TM=1 # < ----- # ... # tbegin # bne # Hardware interrupt # ---- > # # .... # ret_from_except # restore_math() # /* sees FP=0 */ # restore_fp() # tm_active_with_fp() # /* sees FP=1 (Incorrect) */ # load_fp_state() # FP = 0 -> 1 # < ----- # Return to userspace # with MSR TM=1 FP=1 # with junk in the FP TM checkpoint # TM rollback # reads FP junk # # When returning from the hardware exception, tm_active_with_fp() is # incorrectly making restore_fp() call load_fp_state() which is setting # FP=1. # # The fix is to remove tm_active_with_fp(). # # tm_active_with_fp() is attempting to handle the case where FP state # has been changed inside a transaction. In this case the checkpointed # and transactional FP state is different and hence we must restore the # FP state (ie. we can't do lazy FP restore inside a transaction that's # used FP). It's safe to remove tm_active_with_fp() as this case is # handled by restore_tm_state(). restore_tm_state() detects if FP has # been using inside a transaction and will set load_fp and call # restore_math() to ensure the FP state (checkpoint and transaction) is # restored. # # This is a data integrity problem for the current process as the FP # registers are corrupted. It's also a security problem as the FP # registers from one process may be leaked to another. # # Similarly for VMX. # # A simple testcase to replicate this will be posted to # tools/testing/selftests/powerpc/tm/tm-poison.c # # This fixes CVE-2019-15031. # # Fixes: a7771176b439 ("powerpc: Don't enable FP/Altivec if not checkpointed") # Cc: stable@vger.kernel.org # 4.15+ # Signed-off-by: Gustavo Romero # Signed-off-by: Michael Neuling # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20190904045529.23002-2-gromero@linux.vnet.ibm.com # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 a8318c13e79badb92bc6640704a64cc022a6eb97 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- mpc85xx_defconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:194:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2591:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1852:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': /kisskb/src/sound/soc/codecs/wm8960.c:800:70: warning: 'j' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/wm8960.c:797:68: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1465:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/ethernet/freescale/fs_enet/mac-scc.c: In function 'allocate_bd': /kisskb/src/drivers/net/ethernet/freescale/fs_enet/mac-scc.c:139:6: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:248:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:228:19: note: 'i' was declared here /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:338:21: note: 'pdeo' was declared here /kisskb/src/drivers/usb/core/devio.c: In function 'async_completed': /kisskb/src/drivers/usb/core/devio.c:613:23: warning: 'errno' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8541cds.dts:330.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8555cds.dts:330.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) INFO: Uncompressed kernel (size 0xc29680) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5892074 Bytes = 5753.98 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5891868 Bytes = 5753.78 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002e8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5891538 Bytes = 5753.46 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002e8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5892937 Bytes = 5754.82 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5893324 Bytes = 5755.20 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5892141 Bytes = 5754.04 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5891527 Bytes = 5753.44 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5892217 Bytes = 5754.12 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002e8 INFO: Uncompressed kernel (size 0xc18eb8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xd00000) Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:50 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5891885 Bytes = 5753.79 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:51 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5859978 Bytes = 5722.63 KiB = 5.59 MiB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:51 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5891536 Bytes = 5753.45 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002e8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:51 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5892982 Bytes = 5754.87 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:51 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5892640 Bytes = 5754.53 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:51 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5893663 Bytes = 5755.53 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:51 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5892070 Bytes = 5753.97 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002e8 Image Name: Linux-5.3.0-rc2-ga8318c13e79b Created: Wed Sep 4 23:47:51 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5892177 Bytes = 5754.08 KiB = 5.62 MiB Load Address: 00d00000 Entry Point: 00d002a8 Completed OK # rm -rf /kisskb/build/powerpc-fixes_mpc85xx_defconfig_powerpc-gcc4.6 # Build took: 0:01:54.005274