Use grub_divmod64() for the 64-bit modulus to prevent creation of special division calls such as __umoddi3() and __aeabi_uldivmod() on 32-bit platforms.
Signed-off-by: Gary Lin <[email protected]> Reviewed-by: Daniel Kiper <[email protected]> --- conf/Makefile.extra-dist | 1 + .../12-kdf-use-grub_divmod64.patch | 79 +++++++++++++++++++ 2 files changed, 80 insertions(+) create mode 100644 grub-core/lib/libgcrypt-patches/12-kdf-use-grub_divmod64.patch diff --git a/conf/Makefile.extra-dist b/conf/Makefile.extra-dist index bc6768549..48c2b75f8 100644 --- a/conf/Makefile.extra-dist +++ b/conf/Makefile.extra-dist @@ -46,6 +46,7 @@ EXTRA_DIST += grub-core/lib/libgcrypt-patches/08_sexp_leak.patch EXTRA_DIST += grub-core/lib/libgcrypt-patches/09-blake2b-hash-buffers.patch EXTRA_DIST += grub-core/lib/libgcrypt-patches/10-kdf-use-GPG-errs.patch EXTRA_DIST += grub-core/lib/libgcrypt-patches/11-kdf-remove-unsupported-kdfs.patch +EXTRA_DIST += grub-core/lib/libgcrypt-patches/12-kdf-use-grub_divmod64.patch EXTRA_DIST += grub-core/lib/libtasn1-patches/0001-libtasn1-disable-code-not-needed-in-grub.patch EXTRA_DIST += grub-core/lib/libtasn1-patches/0002-libtasn1-replace-strcat-with-strcpy-in-_asn1_str_cat.patch diff --git a/grub-core/lib/libgcrypt-patches/12-kdf-use-grub_divmod64.patch b/grub-core/lib/libgcrypt-patches/12-kdf-use-grub_divmod64.patch new file mode 100644 index 000000000..644485ebf --- /dev/null +++ b/grub-core/lib/libgcrypt-patches/12-kdf-use-grub_divmod64.patch @@ -0,0 +1,79 @@ +From 990a5f7df076200aa031b1bcde6bc4b13d4f198e Mon Sep 17 00:00:00 2001 +From: Gary Lin <[email protected]> +Date: Mon, 25 Aug 2025 16:01:45 +0800 +Subject: [PATCH 4/4] libgcrypt/kdf: Fix 64-bit modulus on 32-bit platforms + +Use grub_divmod64() for the 64-bit modulus to prevent creation of +special division calls such as __umoddi3() and __aeabi_uldivmod() on +32-bit platforms. + +Signed-off-by: Gary Lin <[email protected]> +--- + grub-core/lib/libgcrypt-grub/cipher/kdf.c | 16 ++++++++++++---- + 1 file changed, 12 insertions(+), 4 deletions(-) + +diff --git a/grub-core/lib/libgcrypt-grub/cipher/kdf.c b/grub-core/lib/libgcrypt-grub/cipher/kdf.c +index c51a70eff..f4bb51809 100644 +--- a/grub-core/lib/libgcrypt-grub/cipher/kdf.c ++++ b/grub-core/lib/libgcrypt-grub/cipher/kdf.c +@@ -375,6 +375,7 @@ index_alpha (argon2_ctx_t a, const struct argon2_thread_data *t, + u32 reference_area_size; + u64 relative_position; + u32 start_position; ++ u64 remainder; + + if (t->pass == 0) + { +@@ -411,7 +412,8 @@ index_alpha (argon2_ctx_t a, const struct argon2_thread_data *t, + ? 0 + : (t->slice + 1) * a->segment_length; + +- return (start_position + relative_position) % a->lane_length; ++ grub_divmod64 (start_position + relative_position, a->lane_length, &remainder); ++ return remainder; + } + + static void +@@ -425,6 +427,7 @@ argon2_compute_segment (void *priv) + u64 input_block[1024/sizeof (u64)]; + u64 address_block[1024/sizeof (u64)]; + u64 *random_block = NULL; ++ u64 remainder; + + if (a->hash_type == GCRY_KDF_ARGON2I + || (a->hash_type == GCRY_KDF_ARGON2ID && t->pass == 0 && t->slice < 2)) +@@ -449,7 +452,8 @@ argon2_compute_segment (void *priv) + i = 0; + + curr_offset = t->lane * a->lane_length + t->slice * a->segment_length + i; +- if ((curr_offset % a->lane_length)) ++ grub_divmod64 (curr_offset, a->lane_length, &remainder); ++ if (remainder) + prev_offset = curr_offset - 1; + else + prev_offset = curr_offset + a->lane_length - 1; +@@ -459,7 +463,8 @@ argon2_compute_segment (void *priv) + u64 *ref_block, *curr_block; + u64 rand64; + +- if ((curr_offset % a->lane_length) == 1) ++ grub_divmod64 (curr_offset, a->lane_length, &remainder); ++ if (remainder == 1) + prev_offset = curr_offset - 1; + + if (random_block) +@@ -475,7 +480,10 @@ argon2_compute_segment (void *priv) + if (t->pass == 0 && t->slice == 0) + ref_lane = t->lane; + else +- ref_lane = (rand64 >> 32) % a->lanes; ++ { ++ grub_divmod64 (rand64 >> 32, a->lanes, &remainder); ++ ref_lane = remainder; ++ } + + ref_index = index_alpha (a, t, i, (rand64 & 0xffffffff), + ref_lane == t->lane); +-- +2.51.0 + -- 2.51.0 _______________________________________________ Grub-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/grub-devel
