# git rev-parse -q --verify fa520c47eaa15b9baa8ad66ac18da4a31679693b^{commit} fa520c47eaa15b9baa8ad66ac18da4a31679693b already have revision, skipping fetch # git checkout -q -f -B kisskb fa520c47eaa15b9baa8ad66ac18da4a31679693b # git clean -qxdf # < git log -1 # commit fa520c47eaa15b9baa8ad66ac18da4a31679693b # Author: Eric Sandeen # Date: Wed Oct 17 15:23:59 2018 +0100 # # fscache: Fix out of bound read in long cookie keys # # fscache_set_key() can incur an out-of-bounds read, reported by KASAN: # # BUG: KASAN: slab-out-of-bounds in fscache_alloc_cookie+0x5b3/0x680 [fscache] # Read of size 4 at addr ffff88084ff056d4 by task mount.nfs/32615 # # and also reported by syzbot at https://lkml.org/lkml/2018/7/8/236 # # BUG: KASAN: slab-out-of-bounds in fscache_set_key fs/fscache/cookie.c:120 [inline] # BUG: KASAN: slab-out-of-bounds in fscache_alloc_cookie+0x7a9/0x880 fs/fscache/cookie.c:171 # Read of size 4 at addr ffff8801d3cc8bb4 by task syz-executor907/4466 # # This happens for any index_key_len which is not divisible by 4 and is # larger than the size of the inline key, because the code allocates exactly # index_key_len for the key buffer, but the hashing loop is stepping through # it 4 bytes (u32) at a time in the buf[] array. # # Fix this by calculating how many u32 buffers we'll need by using # DIV_ROUND_UP, and then using kcalloc() to allocate a precleared allocation # buffer to hold the index_key, then using that same count as the hashing # index limit. # # Fixes: ec0328e46d6e ("fscache: Maintain a catalogue of allocated cookies") # Reported-by: syzbot+a95b989b2dde8e806af8@syzkaller.appspotmail.com # Signed-off-by: Eric Sandeen # Cc: stable # Signed-off-by: David Howells # Signed-off-by: Greg Kroah-Hartman # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < git log --format=%s --max-count=1 fa520c47eaa15b9baa8ad66ac18da4a31679693b # < make -s -j 48 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- 44x/fsp2_defconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- INFO: Uncompressed kernel (size 0x8c6c64) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x900000) Image Name: Linux-4.19.0-rc8-gfa520c47eaa1 Created: Fri Oct 19 03:39:24 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 3968822 Bytes = 3875.80 KiB = 3.78 MiB Load Address: 00000000 Entry Point: 00000000 Completed OK # rm -rf /kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 # Build took: 0:00:54.738358