2021-03-02 18:56:20 +00:00
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Darren Kenny <darren.kenny@oracle.com>
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Date: Tue, 3 Nov 2020 16:43:37 +0000
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Subject: [PATCH] libgcrypt/mpi: Fix possible unintended sign extension
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The array of unsigned char gets promoted to a signed 32-bit int before
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it is finally promoted to a size_t. There is the possibility that this
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may result in the signed-bit being set for the intermediate signed
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32-bit int. We should ensure that the promotion is to the correct type
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before we bitwise-OR the values.
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Fixes: CID 96697
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Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
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Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
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---
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grub-core/lib/libgcrypt/mpi/mpicoder.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/grub-core/lib/libgcrypt/mpi/mpicoder.c b/grub-core/lib/libgcrypt/mpi/mpicoder.c
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2022-05-10 07:20:45 +00:00
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index a3435ed14..7ecad27b2 100644
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2021-03-02 18:56:20 +00:00
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--- a/grub-core/lib/libgcrypt/mpi/mpicoder.c
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+++ b/grub-core/lib/libgcrypt/mpi/mpicoder.c
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@@ -458,7 +458,7 @@ gcry_mpi_scan (struct gcry_mpi **ret_mpi, enum gcry_mpi_format format,
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if (len && len < 4)
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return gcry_error (GPG_ERR_TOO_SHORT);
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- n = (s[0] << 24 | s[1] << 16 | s[2] << 8 | s[3]);
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+ n = ((size_t)s[0] << 24 | (size_t)s[1] << 16 | (size_t)s[2] << 8 | (size_t)s[3]);
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s += 4;
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if (len)
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len -= 4;
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