# git rev-parse -q --verify cc7a0bb058b85ea03db87169c60c7cfdd5d34678^{commit} cc7a0bb058b85ea03db87169c60c7cfdd5d34678 already have revision, skipping fetch # git checkout -q -f -B kisskb cc7a0bb058b85ea03db87169c60c7cfdd5d34678 # git clean -qxdf # < git log -1 # commit cc7a0bb058b85ea03db87169c60c7cfdd5d34678 # Author: Tyrel Datwyler # Date: Mon Mar 15 15:48:21 2021 -0600 # # PCI: rpadlpar: Fix potential drc_name corruption in store functions # # Both add_slot_store() and remove_slot_store() try to fix up the # drc_name copied from the store buffer by placing a NUL terminator at # nbyte + 1 or in place of a '\n' if present. However, the static buffer # that we copy the drc_name data into is not zeroed and can contain # anything past the n-th byte. # # This is problematic if a '\n' byte appears in that buffer after nbytes # and the string copied into the store buffer was not NUL terminated to # start with as the strchr() search for a '\n' byte will mark this # incorrectly as the end of the drc_name string resulting in a drc_name # string that contains garbage data after the n-th byte. # # Additionally it will cause us to overwrite that '\n' byte on the stack # with NUL, potentially corrupting data on the stack. # # The following debugging shows an example of the drmgr utility writing # "PHB 4543" to the add_slot sysfs attribute, but add_slot_store() # logging a corrupted string value. # # drmgr: drmgr: -c phb -a -s PHB 4543 -d 1 # add_slot_store: drc_name = PHB 4543°|<82>!, rc = -19 # # Fix this by using strscpy() instead of memcpy() to ensure the string # is NUL terminated when copied into the static drc_name buffer. # Further, since the string is now NUL terminated the code only needs to # change '\n' to '\0' when present. # # Cc: stable@vger.kernel.org # Signed-off-by: Tyrel Datwyler # [mpe: Reformat change log and add mention of possible stack corruption] # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20210315214821.452959-1-tyreld@linux.ibm.com # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 cc7a0bb058b85ea03db87169c60c7cfdd5d34678 # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pasemi_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- pasemi_defconfig # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pasemi_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pasemi_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pasemi_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- Completed OK # rm -rf /kisskb/build/powerpc-fixes_pasemi_defconfig_powerpc-gcc4.9 # Build took: 0:01:50.406285