linux-stable.git/Makefile, branch v6.18.38

Linux 6.18.38

2026-07-04T11:44:22+00:00

Link: https://lore.kernel.org/r/20260702155112.110058792@linuxfoundation.org
Tested-by: Brett A C Sheffield 
Tested-by: Peter Schneider 
Tested-by: Miguel Ojeda 
Tested-by: Shung-Hsi Yu 
Link: https://lore.kernel.org/r/20260703072816.644513463@linuxfoundation.org
Tested-by: Brett A C Sheffield 
Tested-by: Mark Brown 
Tested-by: Ron Economos 
Tested-by: Wentao Guan 
Tested-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

gcov: use atomic counter updates to fix concurrent access crashes

2026-07-04T11:44:17+00:00

commit 56cb9b7d96b28a1173a510ab25354b6599ad3a33 upstream.

GCC's GCOV instrumentation can merge global branch counters with loop
induction variables as an optimization.  In inflate_fast(), the inner copy
loops get transformed so that the GCOV counter value is loaded multiple
times to compute the loop base address, start index, and end bound.  Since
GCOV counters are global (not per-CPU), concurrent execution on different
CPUs causes the counter to change between loads, producing inconsistent
values and out-of-bounds memory writes.

The crash manifests during IPComp (IP Payload Compression) processing when
inflate_fast() runs concurrently on multiple CPUs:

  BUG: unable to handle page fault for address: ffffd0a3c0902ffa
  RIP: inflate_fast+1431
  Call Trace:
   zlib_inflate
   __deflate_decompress
   crypto_comp_decompress
   ipcomp_decompress [xfrm_ipcomp]
   ipcomp_input [xfrm_ipcomp]
   xfrm_input

At the crash point, the compiler generated three loads from the same
global GCOV counter (__gcov0.inflate_fast+216) to compute base, start, and
end for an indexed loop.  Another CPU modified the counter between loads,
making the values inconsistent - the write went 3.4 MB past a 65 KB
buffer.

Add -fprofile-update=prefer-atomic to CFLAGS_GCOV at the global level in
the top-level Makefile, guarded by a try-run compile test.  The test
compiles a minimal program with and without -fprofile-update=prefer-atomic
using the full KBUILD_CFLAGS, then compares undefined symbols in the
resulting object files.  If prefer-atomic introduces new undefined
references (such as __atomic_fetch_add_8 on i386 or __aarch64_ldadd8_relax
on arm64 with outline-atomics), the flag is not added -- the kernel does
not link against libatomic.

On architectures where GCC inlines 64-bit atomic counter updates (x86_64,
s390, ...) the test passes and the flag is enabled, preventing the
compiler from merging counters with loop induction variables and fixing
the observed concurrent-access crash.

On architectures where the flag would introduce libatomic dependencies, it
is silently omitted and behaviour is no worse than before this patch.

Move the CFLAGS_GCOV block from its original position (before the arch
Makefile include) to after the core KBUILD_CFLAGS assignments but before
the scripts/Makefile.gcc-plugins include.  This placement ensures the
try-run test sees arch-specific flags (-m32, -march=,
-mno-outline-atomics) while avoiding GCC plugin flags (-fplugin=) that
would break the test on clean builds when plugin shared objects do not yet
exist.

Link: https://lore.kernel.org/20260511105052.417187-2-khorenko@virtuozzo.com
Signed-off-by: Konstantin Khorenko 
Tested-by: Arnd Bergmann 
Tested-by: Peter Oberparleiter 
Reviewed-by: Peter Oberparleiter 
Cc: Masahiro Yamada 
Cc: Miguel Ojeda 
Cc: Mikhail Zaslonko 
Cc: Nathan Chancellor 
Cc: Pavel Tikhomirov 
Cc: Thomas Weißschuh 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

Linux 6.18.37

2026-06-27T10:06:50+00:00

Link: https://lore.kernel.org/r/20260625125645.554579168@linuxfoundation.org
Tested-by: Florian Fainelli 
Tested-by: Brett A C Sheffield 
Tested-by: Peter Schneider 
Tested-by: Shuah Khan 
Tested-by: Ron Economos 
Tested-by: Miguel Ojeda 
Tested-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

Linux 6.18.36

2026-06-19T11:44:16+00:00

Link: https://lore.kernel.org/r/20260616145057.827196531@linuxfoundation.org
Tested-by: Brett A C Sheffield 
Tested-by: Shung-Hsi Yu 
Tested-by: Wentao Guan 
Tested-by: Miguel Ojeda 
Tested-by: Mark Brown 
Tested-by: Shuah Khan 
Tested-by: Peter Schneider 
Tested-by: Ron Economos 
Tested-by: Pavel Machek (CIP) 
Tested-by: Florian Fainelli 
Tested-by: Willy Tarreau 
Signed-off-by: Greg Kroah-Hartman

rust: kasan/kbuild: fix rustc-option when cross-compiling

2026-06-19T11:44:03+00:00

commit 4a44b17406cb5a93f90af3df9392b3a45eb336fb upstream.

The Makefile version of rustc-option currently checks whether the option
exists for the host target instead of the target actually being compiled
for. It was done this way in commit 46e24a545cdb ("rust: kasan/kbuild:
fix missing flags on first build") to avoid a circular dependency on
target.json. However, because of this, rustc-option currently does not
function when cross-compiling from x86_64 to aarch64 if
CONFIG_SHADOW_CALL_STACK is enabled. This is because KBUILD_RUSTFLAGS
contains -Zfixed-x18 under this configuration. Since that flag does not
exist on the host target, rustc-option runs into a compilation failure
every time, leading to all flags being rejected as unsupported.

To fix this, update rustc-option to pass a --target parameter so that
the host target is not used. For targets using target.json, use a
built-in target that is as close as possible to the target created with
target.json to avoid the circular dependency on target.json.

One scenario where this causes a boot failure:
* Cross-compiled from x86_64 to aarch64.
* With CONFIG_SHADOW_CALL_STACK=y
* With CONFIG_KASAN_SW_TAGS=y
* With CONFIG_KASAN_INLINE=n
Then the resulting kernel image will fail to boot when it first calls
into Rust code with a crash along the lines of "Unable to handle kernel
paging request at virtual address 0ffffffc08541796". This is because the
call threshold is not specified, so rustc will inline kasan operations,
but the kasan shadow offset is not specified, which leads to the inlined
kasan instructions being incorrect.

Note that the -Zsanitizer=kernel-hwaddress parameter itself does not
lead to a rustc-option failure despite being aarch64-specific because
RUSTFLAGS_KASAN has not yet been added to KBUILD_RUSTFLAGS when
rustc-option is evaluated by the kasan Makefile.

Cc: stable@vger.kernel.org
Fixes: 46e24a545cdb ("rust: kasan/kbuild: fix missing flags on first build")
Signed-off-by: Alice Ryhl 
Link: https://patch.msgid.link/20260507-rustc-option-cross-v2-1-2f650a49c2b5@google.com
[ Edited slightly:
    - Reset variable to avoid using the environment.
    - Use a simply expanded variable flavor for simplicity.
    - Export variable so that behavior in sub-`make`s is consistent.
Signed-off-by: Greg Kroah-Hartman 

  This matches other variables. - Miguel ]
Signed-off-by: Miguel Ojeda

Linux 6.18.35

2026-06-09T10:28:53+00:00

Link: https://lore.kernel.org/r/20260607095727.528828913@linuxfoundation.org
Tested-by: Miguel Ojeda 
Tested-by: Peter Schneider 
Tested-by: Wentao Guan 
Tested-by: Ron Economos 
Tested-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

Linux 6.18.34

2026-06-01T15:51:08+00:00

Link: https://lore.kernel.org/r/20260528194638.371537336@linuxfoundation.org
Tested-by: Ron Economos 
Tested-by: Miguel Ojeda 
Tested-by: Brett A C Sheffield 
Tested-by: Pavel Machek (CIP) 
Tested-by: Peter Schneider 
Tested-by: Wentao Guan 
Tested-by: Florian Fainelli 
Tested-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

Linux 6.18.33

2026-05-23T11:07:21+00:00

Link: https://lore.kernel.org/r/20260520162134.554764788@linuxfoundation.org
Tested-by: Florian Fainelli 
Tested-by: Wentao Guan 
Tested-by: Pavel Machek (CIP) 
Tested-by: Jon Hunter 
Tested-by: Peter Schneider 
Tested-by: Mark Brown 
Tested-by: Brett A C Sheffield 
Tested-by: Ron Economos 
Signed-off-by: Greg Kroah-Hartman

kbuild: Never respect CONFIG_WERROR / W=e to fixdep

2026-05-23T11:07:06+00:00

[ Upstream commit 75f7c47ccd78c947cf1b6ddb18ea453ff0555716 ]

The fixdep hostprog may be built multiple times during a single build.
Once during the configuration phase and later during the regular phase.
As only the regular build phase respects CONFIG_WERROR / W=e, the
compiler flags might change between the phases, leading to rebuilds.

Example, the rebuilds will happen twice on each invocation of the build:

  $ make allyesconfig prepare
  make[1]: Entering directory '/tmp/deleteme'
    HOSTCC  scripts/basic/fixdep
  #
  # No change to .config
  #
    HOSTCC  scripts/basic/fixdep
    DESCEND objtool
    INSTALL libsubcmd_headers
  make[1]: Leaving directory '/tmp/deleteme'

Fix the compilation flags used for scripts/basic/ before
scripts/Makefile.warn is evaluated to stop CONFIG_WERROR / W=e
influencing the fixdep build to avoid the spurious rebuilds.

Fixes: 7ded7d37e5f5 ("scripts/Makefile.extrawarn: Respect CONFIG_WERROR / W=e for hostprogs")
Signed-off-by: Thomas Weißschuh 
Reviewed-by: Nathan Chancellor 
Link: https://patch.msgid.link/20260422-kbuild-scripts-basic-werror-v1-1-8c6912ff22e0@weissschuh.net
Signed-off-by: Nicolas Schier 
Signed-off-by: Sasha Levin

Linux 6.18.32

2026-05-17T15:15:37+00:00

Link: https://lore.kernel.org/r/20260515154657.309489048@linuxfoundation.org
Tested-by: Florian Fainelli 
Tested-by: Pavel Machek (CIP) 
Tested-by: Shuah Khan 
Tested-by: Miguel Ojeda 
Tested-by: Mark Brown 
Tested-by: Brett A C Sheffield 
Link: https://lore.kernel.org/r/20260516102236.209957148@linuxfoundation.org
Tested-by: Brett A C Sheffield 
Tested-by: Ron Economos 
Tested-by: Peter Schneider 
Tested-by: Miguel Ojeda 
Tested-by: Wentao Guan 
Signed-off-by: Greg Kroah-Hartman