From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6979933FE09; Wed, 21 Jan 2026 18:18:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769019485; cv=none; b=kE5Z/tluaoakx8qM38+9etKA/7EF/d9frbpDaCNSmYdFMV4uUOylAtCZoSnWzIM8EMlHLN+dDfEVlSLaKSDHvapd41ctSSQlPXhXECn+nS9luh12GWtGRA4HOn/HHwYTmuNQY3XsJvVxUFrYnJ0f8TMio3GP/iFzvCRPTgtrOw8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769019485; c=relaxed/simple; bh=DJQdbZWJKwFZQnx9KyYvMGaaO+w/ERxAAhzUKewt0x0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=skI10WFeuvvWO7QuDpdkuSNBPuv1gfrsG8QNe3ZNhlG8Oz8z9upCJYmBE1lYfuqCAUWab5dSZ1f01ZOjzmWLrL5VdQngHVXNQTotmYVZremfgQP8ekkRNQOTPxpx6zNH03stIqLSw7FTbqrYmjpkZwUbJE4rknIbmkPpSayBJSk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=XpiMLGQ1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="XpiMLGQ1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6847FC4CEF1; Wed, 21 Jan 2026 18:18:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769019484; bh=DJQdbZWJKwFZQnx9KyYvMGaaO+w/ERxAAhzUKewt0x0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XpiMLGQ1QpkMzkKiH85SjoCJJ7suLc0Qh6zMWQ9x58jsIEWjiLlVIHMKZxkHtXvCa 4GczKXqhoilzve9gVLDoVUXwmkNGDpnUKmf56IPp5mD5Z/0PhyqiAhkzLf2Yl5T3Zq 5Bd0aXDsTLLYM5mHpYFDWe0uCGtHl5+ac5Eo+yRI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Morduan Zang , Ard Biesheuvel Subject: [PATCH 6.12 002/139] efi/cper: Fix cper_bits_to_str buffer handling and return value Date: Wed, 21 Jan 2026 19:14:10 +0100 Message-ID: <20260121181411.544361197@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260121181411.452263583@linuxfoundation.org> References: <20260121181411.452263583@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Morduan Zang commit d7f1b4bdc7108be1b178e1617b5f45c8918e88d7 upstream. The return value calculation was incorrect: `return len - buf_size;` Initially `len = buf_size`, then `len` decreases with each operation. This results in a negative return value on success. Fix by returning `buf_size - len` which correctly calculates the actual number of bytes written. Fixes: a976d790f494 ("efi/cper: Add a new helper function to print bitmasks") Signed-off-by: Morduan Zang Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/efi/cper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -162,7 +162,7 @@ int cper_bits_to_str(char *buf, int buf_ len -= size; str += size; } - return len - buf_size; + return buf_size - len; } EXPORT_SYMBOL_GPL(cper_bits_to_str);