Messages in this thread | | | Date | Mon, 11 Jan 2021 11:52:31 -0800 | From | Kees Cook <> | Subject | Re: [PATCH mips-fixes] MIPS: relocatable: fix possible boot hangup with KASLR enabled |
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On Sun, Jan 10, 2021 at 02:21:05PM +0000, Alexander Lobakin wrote: > LLVM-built Linux triggered a boot hangup with KASLR enabled. > > arch/mips/kernel/relocate.c:get_random_boot() uses linux_banner, > which is a string constant, as a random seed, but accesses it > as an array of unsigned long (in rotate_xor()). > When the address of linux_banner is not aligned to sizeof(long), > such access emits unaligned access exception and hangs the kernel. > > Use PTR_ALIGN() to align input address to sizeof(long) and also > align down the input length to prevent possible access-beyond-end. > > Fixes: 405bc8fd12f5 ("MIPS: Kernel: Implement KASLR using CONFIG_RELOCATABLE") > Cc: stable@vger.kernel.org # 4.7+ > Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Reviewed-by: Kees Cook <keescook@chromium.org>
-- Kees Cook
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