| From 9b16d7bcad1c7fea7f26eb2fb3af1a5ca70ba34e Mon Sep 17 00:00:00 2001 |
| From: Darren Kenny <darren.kenny@oracle.com> |
| Date: Tue, 3 Nov 2020 16:43:37 +0000 |
| Subject: [PATCH] libgcrypt/mpi: Fix possible unintended sign extension |
| |
| The array of unsigned char gets promoted to a signed 32-bit int before |
| it is finally promoted to a size_t. There is the possibility that this |
| may result in the signed-bit being set for the intermediate signed |
| 32-bit int. We should ensure that the promotion is to the correct type |
| before we bitwise-OR the values. |
| |
| Fixes: CID 96697 |
| |
| Signed-off-by: Darren Kenny <darren.kenny@oracle.com> |
| Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> |
| |
| Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=e8814c811132a70f9b55418f7567378a34ad3883] |
| Signed-off-by: Marta Rybczynska <marta.rybczynska@huawei.com> |
| |
| --- |
| grub-core/lib/libgcrypt/mpi/mpicoder.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/grub-core/lib/libgcrypt/mpi/mpicoder.c b/grub-core/lib/libgcrypt/mpi/mpicoder.c |
| index a3435ed..7ecad27 100644 |
| --- a/grub-core/lib/libgcrypt/mpi/mpicoder.c |
| +++ b/grub-core/lib/libgcrypt/mpi/mpicoder.c |
| @@ -458,7 +458,7 @@ gcry_mpi_scan (struct gcry_mpi **ret_mpi, enum gcry_mpi_format format, |
| if (len && len < 4) |
| return gcry_error (GPG_ERR_TOO_SHORT); |
| |
| - n = (s[0] << 24 | s[1] << 16 | s[2] << 8 | s[3]); |
| + n = ((size_t)s[0] << 24 | (size_t)s[1] << 16 | (size_t)s[2] << 8 | (size_t)s[3]); |
| s += 4; |
| if (len) |
| len -= 4; |