Re: [PATCH] efi_loader: Fix buffer underflow If the array index 'i' < 128, the 'codepage' array is accessed using [-128...-1] in efi_unicode_collation.c:262. This can lead to a buffer overflow. Negative index in efi_unicode_collation.c:262. The index of the 'codepage' array should be c-0x80 instead of i-0x80.

On 11/22/22 08:33, Mikhail Ilin wrote:

Fixes: 0bc4b0da7b59 ("efi_loader: EFI_UNICODE_COLLATION_PROTOCOL")

Thank you for reporting the problem.

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Otherwise: Reviewed-by: Heinrich Schuchardt xypron.glpk@gmx.de

Signed-off-by: Mikhail Ilin ilin.mikhail.ol@gmail.com

lib/efi_loader/efi_unicode_collation.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/efi_loader/efi_unicode_collation.c b/lib/efi_loader/efi_unicode_collation.c index c700be8756..282045b556 100644 --- a/lib/efi_loader/efi_unicode_collation.c +++ b/lib/efi_loader/efi_unicode_collation.c @@ -259,7 +259,7 @@ static void EFIAPI efi_fat_to_str(struct efi_unicode_collation_protocol *this, for (i = 0; i < fat_size; ++i) { c = (unsigned char)fat[i]; if (c > 0x80)

• 	c = codepage[i - 0x80];
  

• 	c = codepage[c - 0x80];
  

  string[i] = c; if (!c) break;