linux-stable.git/lib, branch v5.4.58

random32: remove net_rand_state from the latent entropy gcc plugin

2020-08-07T07:34:01+00:00

commit 83bdc7275e6206f560d247be856bceba3e1ed8f2 upstream.

It turns out that the plugin right now ends up being really unhappy
about the change from 'static' to 'extern' storage that happened in
commit f227e3ec3b5c ("random32: update the net random state on interrupt
and activity").

This is probably a trivial fix for the latent_entropy plugin, but for
now, just remove net_rand_state from the list of things the plugin
worries about.

Reported-by: Stephen Rothwell 
Cc: Emese Revfy 
Cc: Kees Cook 
Cc: Willy Tarreau 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

random32: update the net random state on interrupt and activity

2020-08-07T07:34:01+00:00

commit f227e3ec3b5cad859ad15666874405e8c1bbc1d4 upstream.

This modifies the first 32 bits out of the 128 bits of a random CPU's
net_rand_state on interrupt or CPU activity to complicate remote
observations that could lead to guessing the network RNG's internal
state.

Note that depending on some network devices' interrupt rate moderation
or binding, this re-seeding might happen on every packet or even almost
never.

In addition, with NOHZ some CPUs might not even get timer interrupts,
leaving their local state rarely updated, while they are running
networked processes making use of the random state.  For this reason, we
also perform this update in update_process_times() in order to at least
update the state when there is user or system activity, since it's the
only case we care about.

Reported-by: Amit Klein 
Suggested-by: Linus Torvalds 
Cc: Eric Dumazet 
Cc: "Jason A. Donenfeld" 
Cc: Andy Lutomirski 
Cc: Kees Cook 
Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: 
Signed-off-by: Willy Tarreau 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

test_objagg: Fix potential memory leak in error handling

2020-06-30T19:37:04+00:00

[ Upstream commit a6379f0ad6375a707e915518ecd5c2270afcd395 ]

In case of failure of check_expect_hints_stats(), the resources
allocated by objagg_hints_get should be freed. The patch fixes
this issue.

Signed-off-by: Aditya Pakki 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

lib/zlib: remove outdated and incorrect pre-increment optimization

2020-06-24T15:50:39+00:00

[ Upstream commit acaab7335bd6f0c0b54ce3a00bd7f18222ce0f5f ]

The zlib inflate code has an old micro-optimization based on the
assumption that for pre-increment memory accesses, the compiler will
generate code that fits better into the processor's pipeline than what
would be generated for post-increment memory accesses.

This optimization was already removed in upstream zlib in 2016:
https://github.com/madler/zlib/commit/9aaec95e8211

This optimization causes UB according to C99, which says in section 6.5.6
"Additive operators": "If both the pointer operand and the result point to
elements of the same array object, or one past the last element of the
array object, the evaluation shall not produce an overflow; otherwise, the
behavior is undefined".

This UB is not only a theoretical concern, but can also cause trouble for
future work on compiler-based sanitizers.

According to the zlib commit, this optimization also is not optimal
anymore with modern compilers.

Replace uses of OFF, PUP and UP_UNALIGNED with their definitions in the
POSTINC case, and remove the macro definitions, just like in the upstream
patch.

Signed-off-by: Jann Horn 
Signed-off-by: Andrew Morton 
Cc: Mikhail Zaslonko 
Link: http://lkml.kernel.org/r/20200507123112.252723-1-jannh@google.com
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

kasan: stop tests being eliminated as dead code with FORTIFY_SOURCE

2020-06-22T07:31:12+00:00

[ Upstream commit adb72ae1915db28f934e9e02c18bfcea2f3ed3b7 ]

Patch series "Fix some incompatibilites between KASAN and FORTIFY_SOURCE", v4.

3 KASAN self-tests fail on a kernel with both KASAN and FORTIFY_SOURCE:
memchr, memcmp and strlen.

When FORTIFY_SOURCE is on, a number of functions are replaced with
fortified versions, which attempt to check the sizes of the operands.
However, these functions often directly invoke __builtin_foo() once they
have performed the fortify check.  The compiler can detect that the
results of these functions are not used, and knows that they have no other
side effects, and so can eliminate them as dead code.

Why are only memchr, memcmp and strlen affected?
================================================

Of string and string-like functions, kasan_test tests:

 * strchr  ->  not affected, no fortified version
 * strrchr ->  likewise
 * strcmp  ->  likewise
 * strncmp ->  likewise

 * strnlen ->  not affected, the fortify source implementation calls the
               underlying strnlen implementation which is instrumented, not
               a builtin

 * strlen  ->  affected, the fortify souce implementation calls a __builtin
               version which the compiler can determine is dead.

 * memchr  ->  likewise
 * memcmp  ->  likewise

 * memset ->   not affected, the compiler knows that memset writes to its
	       first argument and therefore is not dead.

Why does this not affect the functions normally?
================================================

In string.h, these functions are not marked as __pure, so the compiler
cannot know that they do not have side effects.  If relevant functions are
marked as __pure in string.h, we see the following warnings and the
functions are elided:

lib/test_kasan.c: In function `kasan_memchr':
lib/test_kasan.c:606:2: warning: statement with no effect [-Wunused-value]
  memchr(ptr, '1', size + 1);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~
lib/test_kasan.c: In function `kasan_memcmp':
lib/test_kasan.c:622:2: warning: statement with no effect [-Wunused-value]
  memcmp(ptr, arr, size+1);
  ^~~~~~~~~~~~~~~~~~~~~~~~
lib/test_kasan.c: In function `kasan_strings':
lib/test_kasan.c:645:2: warning: statement with no effect [-Wunused-value]
  strchr(ptr, '1');
  ^~~~~~~~~~~~~~~~
...

This annotation would make sense to add and could be added at any point,
so the behaviour of test_kasan.c should change.

The fix
=======

Make all the functions that are pure write their results to a global,
which makes them live.  The strlen and memchr tests now pass.

The memcmp test still fails to trigger, which is addressed in the next
patch.

[dja@axtens.net: drop patch 3]
  Link: http://lkml.kernel.org/r/20200424145521.8203-2-dja@axtens.net
Fixes: 0c96350a2d2f ("lib/test_kasan.c: add tests for several string/memory API functions")
Signed-off-by: Daniel Axtens 
Signed-off-by: Andrew Morton 
Tested-by: David Gow 
Reviewed-by: Dmitry Vyukov 
Cc: Daniel Micay 
Cc: Andrey Ryabinin 
Cc: Alexander Potapenko 
Link: http://lkml.kernel.org/r/20200423154503.5103-1-dja@axtens.net
Link: http://lkml.kernel.org/r/20200423154503.5103-2-dja@axtens.net
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

lib/mpi: Fix 64-bit MIPS build with Clang

2020-06-22T07:31:00+00:00

[ Upstream commit 18f1ca46858eac22437819937ae44aa9a8f9f2fa ]

When building 64r6_defconfig with CONFIG_MIPS32_O32 disabled and
CONFIG_CRYPTO_RSA enabled:

lib/mpi/generic_mpih-mul1.c:37:24: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast
or build with -fheinous-gnu-extensions
                umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
                ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/mpi/longlong.h:664:22: note: expanded from macro 'umul_ppmm'
                 : "=d" ((UDItype)(w0))
                         ~~~~~~~~~~^~~
lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast
or build with -fheinous-gnu-extensions
                umul_ppmm(prod_high, prod_low, s1_ptr[j], s2_limb);
                ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lib/mpi/longlong.h:668:22: note: expanded from macro 'umul_ppmm'
                 : "=d" ((UDItype)(w1))
                         ~~~~~~~~~~^~~
2 errors generated.

This special case for umul_ppmm for MIPS64r6 was added in
commit bbc25bee37d2b ("lib/mpi: Fix umul_ppmm() for MIPS64r6"), due to
GCC being inefficient and emitting a __multi3 intrinsic.

There is no such issue with clang; with this patch applied, I can build
this configuration without any problems and there are no link errors
like mentioned in the commit above (which I can still reproduce with
GCC 9.3.0 when that commit is reverted). Only use this definition when
GCC is being used.

This really should have been caught by commit b0c091ae04f67 ("lib/mpi:
Eliminate unused umul_ppmm definitions for MIPS") when I was messing
around in this area but I was not testing 64-bit MIPS at the time.

Link: https://github.com/ClangBuiltLinux/linux/issues/885
Reported-by: Dmitry Golovin 
Signed-off-by: Nathan Chancellor 
Signed-off-by: Herbert Xu 
Signed-off-by: Sasha Levin

lib/lzo: fix ambiguous encoding bug in lzo-rle

2020-06-17T14:40:28+00:00

commit b5265c813ce4efbfa2e46fd27cdf9a7f44a35d2e upstream.

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 
Signed-off-by: Andrew Morton 
Cc: Mark Rutland 
Cc: Dave Rodgman 
Cc: Willy Tarreau 
Cc: Sergey Senozhatsky 
Cc: Markus F.X.J. Oberhumer 
Cc: Minchan Kim 
Cc: Nitin Gupta 
Cc: Chao Yu 
Cc: 
Link: http://lkml.kernel.org/r/20200507100203.29785-1-dave.rodgman@arm.com
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

vsprintf: don't obfuscate NULL and error pointers

2020-05-27T15:46:43+00:00

commit 7bd57fbc4a4ddedc664cad0bbced1b469e24e921 upstream.

I don't see what security concern is addressed by obfuscating NULL
and IS_ERR() error pointers, printed with %p/%pK.  Given the number
of sites where %p is used (over 10000) and the fact that NULL pointers
aren't uncommon, it probably wouldn't take long for an attacker to
find the hash that corresponds to 0.  Although harder, the same goes
for most common error values, such as -1, -2, -11, -14, etc.

The NULL part actually fixes a regression: NULL pointers weren't
obfuscated until commit 3e5903eb9cff ("vsprintf: Prevent crash when
dereferencing invalid pointers") which went into 5.2.  I'm tacking
the IS_ERR() part on here because error pointers won't leak kernel
addresses and printing them as pointers shouldn't be any different
from e.g. %d with PTR_ERR_OR_ZERO().  Obfuscating them just makes
debugging based on existing pr_debug and friends excruciating.

Note that the "always print 0's for %pK when kptr_restrict == 2"
behaviour which goes way back is left as is.

Example output with the patch applied:

                             ptr         error-ptr              NULL
 %p:            0000000001f8cc5b  fffffffffffffff2  0000000000000000
 %pK, kptr = 0: 0000000001f8cc5b  fffffffffffffff2  0000000000000000
 %px:           ffff888048c04020  fffffffffffffff2  0000000000000000
 %pK, kptr = 1: ffff888048c04020  fffffffffffffff2  0000000000000000
 %pK, kptr = 2: 0000000000000000  0000000000000000  0000000000000000

Fixes: 3e5903eb9cff ("vsprintf: Prevent crash when dereferencing invalid pointers")
Signed-off-by: Ilya Dryomov 
Reviewed-by: Petr Mladek 
Reviewed-by: Sergey Senozhatsky 
Reviewed-by: Andy Shevchenko 
Acked-by: Steven Rostedt (VMware) 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

lib: devres: add a helper function for ioremap_uc

2020-05-10T08:31:30+00:00

[ Upstream commit e537654b7039aacfe8ae629d49655c0e5692ad44 ]

Implement a resource managed strongly uncachable ioremap function.

Cc:  # v4.19+
Tested-by: AceLan Kao 
Signed-off-by: Tuowen Zhao 
Acked-by: Mika Westerberg 
Acked-by: Andy Shevchenko 
Acked-by: Luis Chamberlain 
Signed-off-by: Lee Jones 
Signed-off-by: Sasha Levin

lib/mpi: Fix building for powerpc with clang

2020-05-10T08:31:28+00:00

[ Upstream commit 5990cdee689c6885b27c6d969a3d58b09002b0bc ]

0day reports over and over on an powerpc randconfig with clang:

lib/mpi/generic_mpih-mul1.c:37:13: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast or build with
-fheinous-gnu-extensions

Remove the superfluous casts, which have been done previously for x86
and arm32 in commit dea632cadd12 ("lib/mpi: fix build with clang") and
commit 7b7c1df2883d ("lib/mpi/longlong.h: fix building with 32-bit
x86").

Reported-by: kbuild test robot 
Signed-off-by: Nathan Chancellor 
Acked-by: Herbert Xu 
Signed-off-by: Michael Ellerman 
Link: https://github.com/ClangBuiltLinux/linux/issues/991
Link: https://lore.kernel.org/r/20200413195041.24064-1-natechancellor@gmail.com
Signed-off-by: Sasha Levin