Messages in this thread | | | Date | Thu, 1 Jun 2023 18:34:20 +0100 | From | Conor Dooley <> | Subject | Re: [PATCH v2] riscv/purgatory: Do not use fortified string functions |
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On Thu, Jun 01, 2023 at 09:00:28AM -0700, Kees Cook wrote: > With the addition of -fstrict-flex-arrays=3, struct sha256_state's > trailing array is no longer ignored by CONFIG_FORTIFY_SOURCE: > > struct sha256_state { > u32 state[SHA256_DIGEST_SIZE / 4]; > u64 count; > u8 buf[SHA256_BLOCK_SIZE]; > }; > > This means that the memcpy() calls with "buf" as a destination in > sha256.c's code will attempt to perform run-time bounds checking, which > could lead to calling missing functions, specifically a potential > WARN_ONCE, which isn't callable from purgatory. > > Reported-by: Thorsten Leemhuis <linux@leemhuis.info> > Closes: https://lore.kernel.org/lkml/175578ec-9dec-7a9c-8d3a-43f24ff86b92@leemhuis.info/ > Bisected-by: "Joan Bruguera Micó" <joanbrugueram@gmail.com> > Fixes: df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") > Cc: Paul Walmsley <paul.walmsley@sifive.com> > Cc: Palmer Dabbelt <palmer@dabbelt.com> > Cc: Albert Ou <aou@eecs.berkeley.edu> > Cc: Masahiro Yamada <masahiroy@kernel.org> > Cc: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Thanks for the quick update Kees, Conor. [unhandled content-type:application/pgp-signature] | |