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  1. 17 Jun, 2017 36 commits
  3. 14 Jun, 2017 4 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.4.72 · 30c9187f
      Greg Kroah-Hartman authored
      30c9187f
    • Mark Rutland's avatar
      arm64: ensure extension of smp_store_release value · 4e528eb9
      Mark Rutland authored 
      commit 994870be upstream.

When an inline assembly operand's type is narrower than the register it
is allocated to, the least significant bits of the register (up to the
operand type's width) are valid, and any other bits are permitted to
contain any arbitrary value. This aligns with the AAPCS64 parameter
passing rules.

Our __smp_store_release() implementation does not account for this, and
implicitly assumes that operands have been zero-extended to the width of
the type being stored to. Thus, we may store unknown values to memory
when the value type is narrower than the pointer type (e.g. when storing
a char to a long).

This patch fixes the issue by casting the value operand to the same
width as the pointer operand in all cases, which ensures that the value
is zero-extended as we expect. We use the same union trickery as
__smp_load_acquire and {READ,WRITE}_ONCE() to avoid GCC complaining that
pointers are potentially cast to narrower width integers in unreachable
paths.

A whitespace issue at the top of __smp_store_release() is also
corrected.

No changes are necessary for __smp_load_acquire(). Load instructions
implicitly clear any upper bits of the register, and the compiler will
only consider the least significant bits of the register as valid
regardless.

Fixes: 47933ad4 ("arch: Introduce smp_load_acquire(), smp_store_release()")
Fixes: 878a84d5 ("arm64: add missing data types in smp_load_acquire/smp_store_release")
Cc: <stable@vger.kernel.org> # 3.14.x-
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4e528eb9
    • Mark Rutland's avatar
      arm64: armv8_deprecated: ensure extension of addr · 01ce16f4
      Mark Rutland authored 
      commit 55de49f9 upstream.

Our compat swp emulation holds the compat user address in an unsigned
int, which it passes to __user_swpX_asm(). When a 32-bit value is passed
in a register, the upper 32 bits of the register are unknown, and we
must extend the value to 64 bits before we can use it as a base address.

This patch casts the address to unsigned long to ensure it has been
suitably extended, avoiding the potential issue, and silencing a related
warning from clang.

Fixes: bd35a4ad ("arm64: Port SWP/SWPB emulation support from arm")
Cc: <stable@vger.kernel.org> # 3.19.x-
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      01ce16f4
    • Kees Cook's avatar
      usercopy: Adjust tests to deal with SMAP/PAN · 51ff10e7
      Kees Cook authored 
      commit f5f893c5 upstream.

Under SMAP/PAN/etc, we cannot write directly to userspace memory, so
this rearranges the test bytes to get written through copy_to_user().
Additionally drops the bad copy_from_user() test that would trigger a
memcpy() against userspace on failure.

[arnd: the test module was added in 3.14, and this backported patch
       should apply cleanly on all version from 3.14 to 4.10.
       The original patch was in 4.11 on top of a context change
       I saw the bug triggered with kselftest on a 4.4.y stable kernel]
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      51ff10e7
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