# git rev-parse -q --verify 6e693b3ffecb0b478c7050b44a4842854154f715^{commit} 6e693b3ffecb0b478c7050b44a4842854154f715 already have revision, skipping fetch # git checkout -q -f -B kisskb 6e693b3ffecb0b478c7050b44a4842854154f715 # git clean -qxdf # < git log -1 # commit 6e693b3ffecb0b478c7050b44a4842854154f715 # Author: Will Deacon # Date: Sat Jan 19 21:56:05 2019 +0000 # # x86: uaccess: Inhibit speculation past access_ok() in user_access_begin() # # Commit 594cc251fdd0 ("make 'user_access_begin()' do 'access_ok()'") # makes the access_ok() check part of the user_access_begin() preceding a # series of 'unsafe' accesses. This has the desirable effect of ensuring # that all 'unsafe' accesses have been range-checked, without having to # pick through all of the callsites to verify whether the appropriate # checking has been made. # # However, the consolidated range check does not inhibit speculation, so # it is still up to the caller to ensure that they are not susceptible to # any speculative side-channel attacks for user addresses that ultimately # fail the access_ok() check. # # This is an oversight, so use __uaccess_begin_nospec() to ensure that # speculation is inhibited until the access_ok() check has passed. # # Reported-by: Julien Thierry # Signed-off-by: Will Deacon # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-gcc --version # < /opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-ld --version # < git log --format=%s --max-count=1 6e693b3ffecb0b478c7050b44a4842854154f715 # < make -s -j 48 ARCH=mips O=/kisskb/build/linus_mips-allnoconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux- allnoconfig # make -s -j 48 ARCH=mips O=/kisskb/build/linus_mips-allnoconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux- FIT description: Linux 5.0.0-rc2+ Created: Sun Jan 20 16:17:58 2019 Image 0 (kernel@0) Description: Linux 5.0.0-rc2+ Created: Sun Jan 20 16:17:58 2019 Type: Kernel Image Compression: gzip compressed Data Size: 631728 Bytes = 616.92 KiB = 0.60 MiB Architecture: MIPS OS: Linux Load Address: 0x80100000 Entry Point: 0x8021ae80 Hash algo: sha1 Hash value: 0ff1f052fd8d5339e7c102f711959383c85592ae Default Configuration: 'conf@default' Configuration 0 (conf@default) Description: Generic Linux kernel Kernel: kernel@0 Completed OK # rm -rf /kisskb/build/linus_mips-allnoconfig_mipsel # Build took: 0:00:16.375059