Buildresult: powerpc-next/powerpc-allnoconfig/powerpc-gcc4.6 built on Dec 13 2018, 01:12

kisskb

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Status:	OK
Date/Time:	Dec 13 2018, 01:12
Duration:	0:00:09.869814
Builder:	ka4
Revision:	powerpc/mm/hash: Handle user access of kernel address gracefully (`61a8426c92ba30d403a1f072e29d713184539cc1)`
Target:	powerpc-next/powerpc-allnoconfig/powerpc-gcc4.6
Branch:	powerpc-next
Compiler:	powerpc-gcc4.6 (powerpc-linux-gcc (GCC) 4.6.3)
Config:	allnoconfig (download)
Log:	Download original Possible warnings (1) kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] Full Log # 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/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_powerpc-allnoconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- allnoconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_powerpc-allnoconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /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] Completed OK # rm -rf /kisskb/build/powerpc-next_powerpc-allnoconfig_powerpc # Build took: 0:00:09.869814

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