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authorKees Cook <[email protected]>2023-06-01 09:00:28 -0700
committerKees Cook <[email protected]>2023-06-05 15:31:07 -0700
commit8762606ae22e71ec65249cdbf809e3dc7ea8ea1e (patch)
tree177ad0c0762bddfaab5ce7806f76d334e9d4b1fb
parent4ce1e94175696b8f5f6fa29f09f7ef56724ddc2a (diff)
riscv/purgatory: Do not use fortified string functions
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 <[email protected]> Closes: https://lore.kernel.org/lkml/[email protected]/ Bisected-by: "Joan Bruguera Micó" <[email protected]> Fixes: df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") Cc: Paul Walmsley <[email protected]> Cc: Palmer Dabbelt <[email protected]> Cc: Albert Ou <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Conor Dooley <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Alyssa Ross <[email protected]> Cc: Heiko Stuebner <[email protected]> Cc: "Gustavo A. R. Silva" <[email protected]> Cc: [email protected] Signed-off-by: Kees Cook <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Reviewed-by: Palmer Dabbelt <[email protected]> Acked-by: Palmer Dabbelt <[email protected]> Link: https://lore.kernel.org/r/[email protected]
-rw-r--r--arch/riscv/purgatory/Makefile2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/riscv/purgatory/Makefile b/arch/riscv/purgatory/Makefile
index 5730797a6b40..8c73360c42bb 100644
--- a/arch/riscv/purgatory/Makefile
+++ b/arch/riscv/purgatory/Makefile
@@ -31,7 +31,7 @@ $(obj)/strncmp.o: $(srctree)/arch/riscv/lib/strncmp.S FORCE
$(obj)/sha256.o: $(srctree)/lib/crypto/sha256.c FORCE
$(call if_changed_rule,cc_o_c)
-CFLAGS_sha256.o := -D__DISABLE_EXPORTS
+CFLAGS_sha256.o := -D__DISABLE_EXPORTS -D__NO_FORTIFY
CFLAGS_string.o := -D__DISABLE_EXPORTS
CFLAGS_ctype.o := -D__DISABLE_EXPORTS