# 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/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-ld --version # < git log --format=%s --max-count=1 6e693b3ffecb0b478c7050b44a4842854154f715 # < make -s -j 48 ARCH=arm O=/kisskb/build/linus_lart_defconfig_arm CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi- lart_defconfig # make -s -j 48 ARCH=arm O=/kisskb/build/linus_lart_defconfig_arm CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi- /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:339:21: note: 'pdeo' was declared here /kisskb/src/net/ipv4/ip_output.c: In function '__ip_append_data': /kisskb/src/include/linux/skbuff.h:1338:6: warning: 'extra_uref' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/ipv4/ip_output.c:885:14: note: 'extra_uref' was declared here /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] Completed OK # rm -rf /kisskb/build/linus_lart_defconfig_arm # Build took: 0:00:36.568174