b5265c813c
In some rare cases, for input data over 32 KB, lzo-rle could encode two different inputs to the same compressed representation, so that decompression is then ambiguous (i.e. data may be corrupted - although zram is not affected because it operates over 4 KB pages). This modifies the compressor without changing the decompressor or the bitstream format, such that: - there is no change to how data produced by the old compressor is decompressed - an old decompressor will correctly decode data from the updated compressor - performance and compression ratio are not affected - we avoid introducing a new bitstream format In testing over 12.8M real-world files totalling 903 GB, three files were affected by this bug. I also constructed 37M semi-random 64 KB files totalling 2.27 TB, and saw no affected files. Finally I tested over files constructed to contain each of the ~1024 possible bad input sequences; for all of these cases, updated lzo-rle worked correctly. There is no significant impact to performance or compression ratio. Signed-off-by: Dave Rodgman <dave.rodgman@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Dave Rodgman <dave.rodgman@arm.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Markus F.X.J. Oberhumer <markus@oberhumer.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Chao Yu <yuchao0@huawei.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200507100203.29785-1-dave.rodgman@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
ABI | ||
accounting | ||
admin-guide | ||
arm | ||
arm64 | ||
block | ||
bpf | ||
cdrom | ||
core-api | ||
cpu-freq | ||
crypto | ||
dev-tools | ||
devicetree | ||
doc-guide | ||
driver-api | ||
fault-injection | ||
fb | ||
features | ||
filesystems | ||
firmware_class | ||
firmware-guide | ||
fpga | ||
gpu | ||
hid | ||
hwmon | ||
i2c | ||
ia64 | ||
ide | ||
iio | ||
infiniband | ||
input | ||
isdn | ||
kbuild | ||
kernel-hacking | ||
leds | ||
livepatch | ||
locking | ||
m68k | ||
maintainer | ||
mhi | ||
mips | ||
misc-devices | ||
netlabel | ||
networking | ||
nios2 | ||
nvdimm | ||
openrisc | ||
parisc | ||
PCI | ||
pcmcia | ||
power | ||
powerpc | ||
process | ||
RCU | ||
riscv | ||
s390 | ||
scheduler | ||
scsi | ||
security | ||
sh | ||
sound | ||
sparc | ||
sphinx | ||
sphinx-static | ||
spi | ||
target | ||
timers | ||
trace | ||
translations | ||
usb | ||
userspace-api | ||
virt | ||
vm | ||
w1 | ||
watchdog | ||
x86 | ||
xtensa | ||
.gitignore | ||
asm-annotations.rst | ||
atomic_bitops.txt | ||
atomic_t.txt | ||
bus-virt-phys-mapping.txt | ||
Changes | ||
CodingStyle | ||
conf.py | ||
COPYING-logo | ||
crc32.txt | ||
docutils.conf | ||
dontdiff | ||
index.rst | ||
Kconfig | ||
kprobes.txt | ||
logo.gif | ||
lzo.txt | ||
mailbox.txt | ||
Makefile | ||
memory-barriers.txt | ||
nommu-mmap.txt | ||
remoteproc.txt | ||
rpmsg.txt | ||
speculation.txt | ||
static-keys.txt | ||
SubmittingPatches | ||
tee.txt | ||
this_cpu_ops.txt | ||
xz.txt |