# git rev-parse -q --verify a68a0262abdaa251e12c53715f48e698a18ef402^{commit}
a68a0262abdaa251e12c53715f48e698a18ef402
already have revision, skipping fetch
# git checkout -q -f -B kisskb a68a0262abdaa251e12c53715f48e698a18ef402
# git clean -qxdf
# < git log -1
# commit a68a0262abdaa251e12c53715f48e698a18ef402
# Author: Minchan Kim <minchan@kernel.org>
# Date:   Tue Dec 8 20:57:18 2020 -0800
# 
#     mm/madvise: remove racy mm ownership check
#     
#     Jann spotted the security hole due to race of mm ownership check.
#     
#     If the task is sharing the mm_struct but goes through execve() before
#     mm_access(), it could skip process_madvise_behavior_valid check.  That
#     makes *any advice hint* to reach into the remote process.
#     
#     This patch removes the mm ownership check.  With it, it will lose the
#     ability that local process could give *any* advice hint with vector
#     interface for some reason (e.g., performance).  Since there is no
#     concrete example in upstream yet, it would be better to remove the
#     abiliity at this moment and need to review when such new advice comes
#     up.
#     
#     Fixes: ecb8ac8b1f14 ("mm/madvise: introduce process_madvise() syscall: an external memory hinting API")
#     Reported-by: Jann Horn <jannh@google.com>
#     Suggested-by: Jann Horn <jannh@google.com>
#     Signed-off-by: Minchan Kim <minchan@kernel.org>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux-ld --version
# < git log --format=%s --max-count=1 a68a0262abdaa251e12c53715f48e698a18ef402
# < make -s -j 40 ARCH=sh O=/kisskb/build/linus_rsk7201_defconfig_sh4-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux-  rsk7201_defconfig
# make -s -j 40 ARCH=sh O=/kisskb/build/linus_rsk7201_defconfig_sh4-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/sh4-linux/bin/sh4-linux-  
  Generating include/generated/machtypes.h
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
/kisskb/src/drivers/tty/serial/sh-sci.c: In function 'sci_remap_port':
/kisskb/src/drivers/tty/serial/sh-sci.c:2677:19: warning: unused variable 'sport' [-Wunused-variable]
  struct sci_port *sport = to_sci_port(port);
                   ^
Image Name:   Linux-5.10.0-rc7+
Created:      Wed Dec  9 19:27:50 2020
Image Type:   SuperH Linux Kernel Image (gzip compressed)
Data Size:    1701777 Bytes = 1661.89 KiB = 1.62 MiB
Load Address: 08001000
Entry Point:  08002000
  Image arch/sh/boot/uImage is ready
Completed OK
# rm -rf /kisskb/build/linus_rsk7201_defconfig_sh4-gcc4.9
# Build took: 0:00:17.102310