# git rev-parse -q --verify 467f8165a2b0e6accf3d0dd9c8089b1dbde29f7f^{commit}
467f8165a2b0e6accf3d0dd9c8089b1dbde29f7f
already have revision, skipping fetch
# git checkout -q -f -B kisskb 467f8165a2b0e6accf3d0dd9c8089b1dbde29f7f
# git clean -qxdf
# < git log -1
# commit 467f8165a2b0e6accf3d0dd9c8089b1dbde29f7f
# Merge: 3872f516aab3 6abc20f8f879
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Sat Dec 19 13:03:12 2020 -0800
# 
#     Merge tag 'close-range-cloexec-unshare-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
#     
#     Pull close_range fix from Christian Brauner:
#      "syzbot reported a bug when asking close_range() to unshare the file
#       descriptor table and making all fds close-on-exec.
#     
#       If CLOSE_RANGE_UNSHARE the caller will receive a private file
#       descriptor table in case their file descriptor table is currently
#       shared before operating on the requested file descriptor range.
#     
#       For the case where the caller has requested all file descriptors to be
#       actually closed via e.g. close_range(3, ~0U, CLOSE_RANGE_UNSHARE) the
#       kernel knows that the caller does not need any of the file descriptors
#       anymore and will optimize the close operation by only copying all
#       files in the range from 0 to 3 and no others.
#     
#       However, if the caller requested CLOSE_RANGE_CLOEXEC together with
#       CLOSE_RANGE_UNSHARE the caller wants to still make use of the file
#       descriptors so the kernel needs to copy all of them and can't
#       optimize.
#     
#       The original patch didn't account for this and thus could cause oopses
#       as evidenced by the syzbot report because it assumed that all fds had
#       been copied. Fix this by handling the CLOSE_RANGE_CLOEXEC case and
#       copying all fds if the two flags are specified together.
#     
#       This should've been caught in the selftests but the original patch
#       didn't cover this case and I didn't catch it during review. So in
#       addition to the bugfix I'm also adding selftests. They will reliably
#       reproduce the bug on a non-fixed kernel and allows us to catch
#       regressions and verify correct behavior.
#     
#       Note, the kernel selftest tree contained a bunch of changes that made
#       the original selftest fail to compile so there are small fixups in
#       here make them compile without warnings"
#     
#     * tag 'close-range-cloexec-unshare-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
#       selftests/core: add regression test for CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC
#       selftests/core: add test for CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC
#       selftests/core: handle missing syscall number for close_range
#       selftests/core: fix close_range_test build after XFAIL removal
#       close_range: unshare all fds for CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC
# < /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 467f8165a2b0e6accf3d0dd9c8089b1dbde29f7f
# < make -s -j 120 ARCH=powerpc O=/kisskb/build/linus_corenet32_smp_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  corenet32_smp_defconfig
# make -s -j 120 ARCH=powerpc O=/kisskb/build/linus_corenet32_smp_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  
INFO: Uncompressed kernel (size 0xe6a73c) overlaps the address of the wrapper(0x400000)
INFO: Fixing the link_address of wrapper to (0xf00000)
Image Name:   Linux-5.10.0-g467f8165a2b0
Created:      Sun Dec 20 08:51:48 2020
Image Type:   PowerPC Linux Kernel Image (gzip compressed)
Data Size:    6794451 Bytes = 6635.21 KiB = 6.48 MiB
Load Address: 00000000
Entry Point:  00000000
Completed OK
# rm -rf /kisskb/build/linus_corenet32_smp_defconfig_powerpc-gcc4.9
# Build took: 0:01:19.625913