# 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 <aneesh.kumar@linux.ibm.com>
# 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 <aneesh.kumar@linux.ibm.com>
#     Tested-by: Breno Leitao <leitao@debian.org>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/i386-linux/bin/i386-linux-gcc --version
# < git log --format=%s --max-count=1 61a8426c92ba30d403a1f072e29d713184539cc1
# < make -s -j 80 ARCH=i386 O=/kisskb/build/powerpc-next_i386_defconfig_i386 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/i386-linux/bin/i386-linux-  i386_defconfig
# make -s -j 80 ARCH=i386 O=/kisskb/build/powerpc-next_i386_defconfig_i386 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/i386-linux/bin/i386-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/rcu/srcutree.c: In function 'init_srcu_struct_fields':
/kisskb/src/kernel/rcu/srcutree.c:152:32: warning: 'levelspread[<U5b40>]' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c:100:6: note: 'levelspread[<U5b40>]' was declared here
/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/arch/x86/kernel/e820.c: In function 'e820__setup_pci_gap':
/kisskb/src/arch/x86/kernel/e820.c:652:2: warning: 'gapstart' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/arch/x86/kernel/apic/io_apic.c: In function 'mp_map_pin_to_irq':
/kisskb/src/arch/x86/kernel/apic/io_apic.c:1034:6: warning: 'irq' 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/sound/hda/hdac_regmap.c: In function 'hda_reg_write':
/kisskb/src/sound/hda/hdac_regmap.c:282:16: warning: 'err' 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/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/drivers/dma-buf/reservation.c: In function 'reservation_object_add_shared_fence':
/kisskb/src/drivers/dma-buf/reservation.c:208:2: warning: 'k' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/dma-buf/reservation.c:161:17: note: 'k' was declared here
/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/net/mac80211/mlme.c: In function 'ieee80211_rx_mgmt_beacon':
/kisskb/src/net/mac80211/mlme.c:1513:3: warning: 'pwr_level_cisco' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/mac80211/mlme.c:1470:6: note: 'pwr_level_cisco' was declared here
Completed OK
# rm -rf /kisskb/build/powerpc-next_i386_defconfig_i386
# Build took: 0:01:32.858729