Buildresult: linus/ppc64le_defconfig/powerpc-gcc5 built on Jan 9 2019, 13:42
kisskb
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Status:
OK
Date/Time:
Jan 9 2019, 13:42
Duration:
0:03:54.120609
Builder:
ka2
Revision:
fork: record start_time late (
7b55851367136b1efd84d98fea81ba57a98304cf)
Target:
linus/ppc64le_defconfig/powerpc-gcc5
Branch:
linus
Compiler:
powerpc-gcc5
(powerpc64-linux-gcc (GCC) 5.5.0 / GNU ld (GNU Binutils) 2.29.1.20170915)
Config:
ppc64le_defconfig
(
download
)
Log:
Download original
Possible warnings (1)
WARNING: modpost: Found 3 section mismatch(es).
Full Log
# git rev-parse -q --verify 7b55851367136b1efd84d98fea81ba57a98304cf^{commit} 7b55851367136b1efd84d98fea81ba57a98304cf already have revision, skipping fetch # git checkout -q -f -B kisskb 7b55851367136b1efd84d98fea81ba57a98304cf # git clean -qxdf # < git log -1 # commit 7b55851367136b1efd84d98fea81ba57a98304cf # Author: David Herrmann <dh.herrmann@gmail.com> # Date: Tue Jan 8 13:58:52 2019 +0100 # # fork: record start_time late # # This changes the fork(2) syscall to record the process start_time after # initializing the basic task structure but still before making the new # process visible to user-space. # # Technically, we could record the start_time anytime during fork(2). But # this might lead to scenarios where a start_time is recorded long before # a process becomes visible to user-space. For instance, with # userfaultfd(2) and TLS, user-space can delay the execution of fork(2) # for an indefinite amount of time (and will, if this causes network # access, or similar). # # By recording the start_time late, it much closer reflects the point in # time where the process becomes live and can be observed by other # processes. # # Lastly, this makes it much harder for user-space to predict and control # the start_time they get assigned. Previously, user-space could fork a # process and stall it in copy_thread_tls() before its pid is allocated, # but after its start_time is recorded. This can be misused to later-on # cycle through PIDs and resume the stalled fork(2) yielding a process # that has the same pid and start_time as a process that existed before. # This can be used to circumvent security systems that identify processes # by their pid+start_time combination. # # Even though user-space was always aware that start_time recording is # flaky (but several projects are known to still rely on start_time-based # identification), changing the start_time to be recorded late will help # mitigate existing attacks and make it much harder for user-space to # control the start_time a process gets assigned. # # Reported-by: Jann Horn <jannh@google.com> # Signed-off-by: Tom Gundersen <teg@jklm.no> # Signed-off-by: David Herrmann <dh.herrmann@gmail.com> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 7b55851367136b1efd84d98fea81ba57a98304cf # < make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_ppc64le_defconfig_ppc64le-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- ppc64le_defconfig # make -s -j 8 ARCH=powerpc O=/kisskb/build/linus_ppc64le_defconfig_ppc64le-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- WARNING: modpost: Found 3 section mismatch(es). To see full details build your kernel with: 'make CONFIG_DEBUG_SECTION_MISMATCH=y' Completed OK # rm -rf /kisskb/build/linus_ppc64le_defconfig_ppc64le-gcc5 # Build took: 0:03:54.120609
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