# git rev-parse -q --verify ae085d7f9365de7da27ab5c0d16b12d51ea7fca9^{commit} ae085d7f9365de7da27ab5c0d16b12d51ea7fca9 already have revision, skipping fetch # git checkout -q -f -B kisskb ae085d7f9365de7da27ab5c0d16b12d51ea7fca9 # git clean -qxdf # < git log -1 # commit ae085d7f9365de7da27ab5c0d16b12d51ea7fca9 # Author: Muchun Song # Date: Sun Mar 27 13:18:52 2022 +0800 # # mm: kfence: fix missing objcg housekeeping for SLAB # # The objcg is not cleared and put for kfence object when it is freed, # which could lead to memory leak for struct obj_cgroup and wrong # statistics of NR_SLAB_RECLAIMABLE_B or NR_SLAB_UNRECLAIMABLE_B. # # Since the last freed object's objcg is not cleared, # mem_cgroup_from_obj() could return the wrong memcg when this kfence # object, which is not charged to any objcgs, is reallocated to other # users. # # A real word issue [1] is caused by this bug. # # Link: https://lore.kernel.org/all/000000000000cabcb505dae9e577@google.com/ [1] # Reported-by: syzbot+f8c45ccc7d5d45fc5965@syzkaller.appspotmail.com # Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB") # Signed-off-by: Muchun Song # Cc: Dmitry Vyukov # Cc: Marco Elver # Cc: Andrew Morton # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/s390-linux/bin/s390-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/s390-linux/bin/s390-linux-ld --version # < git log --format=%s --max-count=1 ae085d7f9365de7da27ab5c0d16b12d51ea7fca9 # < make -s -j 48 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/s390-linux/bin/s390-linux- defconfig # Added to kconfig CONFIG_DEBUG_INFO_BTF=n # Added to kconfig # < make -s -j 48 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/s390-linux/bin/s390-linux- help # make -s -j 48 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/s390-linux/bin/s390-linux- olddefconfig # make -s -j 48 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/s390-linux/bin/s390-linux- /kisskb/src/arch/s390/kernel/machine_kexec.c: In function '__do_machine_kdump': /kisskb/src/arch/s390/kernel/machine_kexec.c:57:9: warning: 'memcpy' offset [0, 511] is out of the bounds [0, 0] [-Warray-bounds] 57 | memcpy((void *) __LC_FPREGS_SAVE_AREA, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 58 | (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Completed OK # rm -rf /kisskb/build/linus_s390-defconfig_s390x-gcc11 # Build took: 0:05:50.860737