# git rev-parse -q --verify 61a8426c92ba30d403a1f072e29d713184539cc1^{commit} 61a8426c92ba30d403a1f072e29d713184539cc1 already have revision, skipping fetch # git checkout -q -f -B kisskb 61a8426c92ba30d403a1f072e29d713184539cc1 # git clean -qxdf # < git log -1 # commit 61a8426c92ba30d403a1f072e29d713184539cc1 # Author: Aneesh Kumar K.V # Date: Mon Nov 26 20:05:04 2018 +0530 # # powerpc/mm/hash: Handle user access of kernel address gracefully # # In commit 2865d08dd9ea ("powerpc/mm: Move the DSISR_PROTFAULT sanity # check") we moved the protection fault access check before the vma # lookup. That means we hit that WARN_ON when user space accesses a # kernel address. Before that commit this was handled by find_vma() not # finding vma for the kernel address and considering that access as bad # area access. # # Avoid the confusing WARN_ON and convert that to a ratelimited printk. # # With the patch we now get: # # for load: # a.out[5997]: User access of kernel address (c00000000000dea0) - exploit attempt? (uid: 1000) # a.out[5997]: segfault (11) at c00000000000dea0 nip 1317c0798 lr 7fff80d6441c code 1 in a.out[1317c0000+10000] # a.out[5997]: code: 60000000 60420000 3c4c0002 38427790 4bffff20 3c4c0002 38427784 fbe1fff8 # a.out[5997]: code: f821ffc1 7c3f0b78 60000000 e9228030 <89290000> 993f002f 60000000 383f0040 # # for exec: # a.out[6067]: User access of kernel address (c00000000000dea0) - exploit attempt? (uid: 1000) # a.out[6067]: segfault (11) at c00000000000dea0 nip c00000000000dea0 lr 129d507b0 code 1 # a.out[6067]: Bad NIP, not dumping instructions. # # Fixes: 2865d08dd9ea ("powerpc/mm: Move the DSISR_PROTFAULT sanity check") # Signed-off-by: Aneesh Kumar K.V # Tested-by: Breno Leitao # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < git log --format=%s --max-count=1 61a8426c92ba30d403a1f072e29d713184539cc1 # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_pseries_defconfig+NO_MEMORY_HOTREMOVE_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- pseries_defconfig # Added to kconfig CONFIG_MEMORY_HOTPLUG=y # Added to kconfig CONFIG_MEMORY_HOTREMOVE=n # yes \n | make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_pseries_defconfig+NO_MEMORY_HOTREMOVE_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- oldconfig yes: standard output: Broken pipe # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_pseries_defconfig+NO_MEMORY_HOTREMOVE_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/kernel/cgroup/cgroup-v1.c: In function 'cgroup1_mount': /kisskb/src/kernel/cgroup/cgroup-v1.c:1256:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized] /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/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2594:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1855:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1433:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' 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:341:21: note: 'pdeo' 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] /kisskb/src/net/bridge/br_netlink.c: In function 'br_afspec': /kisskb/src/net/bridge/br_netlink.c:647:7: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc': /kisskb/src/fs/nfsd/nfs4xdr.c:2076:9: warning: 'str' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:227:19: note: 'i' was declared here /kisskb/src/drivers/net/tun.c: In function 'tun_get_user': /kisskb/src/drivers/net/tun.c:1819:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1729:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] Completed OK # rm -rf /kisskb/build/powerpc-next_pseries_defconfig+NO_MEMORY_HOTREMOVE_powerpc # Build took: 0:01:25.191889