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 06F6429A2; Mon, 4 Aug 2025 00:27:24 +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=1754267244; cv=none; b=NI9umBUpSmJ8IxvP8SFwMx7CKtDDG8AoyXdH1PN0bHyZ8hosP9l0WifmkucloU3xiR1gxEig5QLPQJoGrY7jI2S79b6qsD0xAokp9Rm1VO9G8r1qKESy778/ZmQ2AdXyitkYSMmgjthaoV9w9SreSinmckNCJ4DYgPMs119tddQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754267244; c=relaxed/simple; bh=xx+cMnBca5FdB4NqdtJoNYBKpU8YHM9fYDGzhuRR+d8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=CFVoj9p3rEqi6H0HecIsT7CKInwZ8A8P/HTKhC2Nel9Vv8E2k0eZX1zkeoTRLft2T7qVNWGI8Y1zraVsnstaGGqaYvSgLpAK8A4vIaRj1wmGXqxCg3CqoTLO2og6sdWI424F6GEv9Gjn3gMrArng+91JuLqZLzxScCROIzyvh1E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SSGHJJ0+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SSGHJJ0+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88BB9C4CEEB; Mon, 4 Aug 2025 00:27:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754267243; bh=xx+cMnBca5FdB4NqdtJoNYBKpU8YHM9fYDGzhuRR+d8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SSGHJJ0+kKA/MoQ6FUHf5U957BvCVynHBzPZxmkvAEib3Ssl215kO7HJx/x3G6bKi Ks4chw6m1oyhn95kaKfxBU29OsLfk6OK+/rgTdQs8sMSZHtdhszzwzyhuvMvLzBAv3 8VwmKMbzRWiE6JCGFrnNfVOHS2vAsDsl4DBlZAyIDWLiTezkNsbaVVTgRCsbL1oGn2 ywTIpN8DEglDCHGfdE3or7WHtbMsdi/x/kH6uESp+5RlIGKGIerho8qO9HMF4ssk1r eAGkqVKwdh54kgQjnINgwGh+WDDyuclQlQ7YBQta+pjO9NCX+kQtFn61V8XiWIvPUa Y9jmslW293nAg== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Bjorn Andersson , Dmitry Baryshkov , Bjorn Andersson , Sasha Levin , konradybcio@kernel.org, linux-arm-msm@vger.kernel.org Subject: [PATCH AUTOSEL 6.16 77/85] soc: qcom: mdt_loader: Actually use the e_phoff Date: Sun, 3 Aug 2025 20:23:26 -0400 Message-Id: <20250804002335.3613254-77-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250804002335.3613254-1-sashal@kernel.org> References: <20250804002335.3613254-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.16 Content-Transfer-Encoding: 8bit From: Bjorn Andersson [ Upstream commit 47e339cac89143709e84a3b71ba8bd9b2fdd2368 ] Rather than relying/assuming that the tools generating the firmware places the program headers immediately following the ELF header, use e_phoff as intended to find the program headers. Reviewed-by: Dmitry Baryshkov Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20250610-mdt-loader-validation-and-fixes-v2-3-f7073e9ab899@oss.qualcomm.com Signed-off-by: Bjorn Andersson Signed-off-by: Sasha Levin --- LLM Generated explanations, may be completely bogus: Based on my analysis of the commit and code changes, I can now provide my assessment: **Backport Status: YES** This commit should be backported to stable kernel trees for the following reasons: 1. **Bug Fix**: The commit fixes a genuine bug where the code was incorrectly assuming that program headers immediately follow the ELF header instead of using the `e_phoff` (ELF header's program header offset) field. This is a clear violation of the ELF specification. 2. **Security Implications**: The bug could lead to incorrect parsing of firmware files, potentially causing: - Out-of-bounds memory access if `e_phoff` points to a location beyond `sizeof(ehdr)` - Loading incorrect data as program headers - Firmware loading failures or crashes in Qualcomm devices 3. **Minimal Risk**: The fix is simple and contained - it changes 4 lines in the same pattern: ```c - phdrs = (struct elf32_phdr *)(ehdr + 1); + phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff); ``` 4. **Affects Multiple Functions**: The bug affects critical firmware loading functions: - `qcom_mdt_get_size()` - calculates memory requirements - `qcom_mdt_read_metadata()` - reads firmware metadata for authentication - `qcom_mdt_pas_init()` - initializes firmware loading - `qcom_mdt_bins_are_split()` - determines firmware structure - `__qcom_mdt_load()` - performs actual firmware loading 5. **Real-World Impact**: This affects Qualcomm device firmware loading, which is used in many Android devices and embedded systems. Incorrect firmware loading could lead to device failures. 6. **Clear Fix**: The commit message clearly explains the issue and the fix follows ELF specification standards by properly using `e_phoff` instead of making assumptions about file layout. 7. **Stable Tree Criteria Met**: - Fixes a real bug that affects users - Small, self-contained change - No architectural changes - Low risk of regression - Important for device stability The fix ensures proper ELF parsing according to specification and prevents potential security issues from incorrect memory access during firmware loading on Qualcomm platforms. drivers/soc/qcom/mdt_loader.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c index b2c0fb55d4ae..44589d10b15b 100644 --- a/drivers/soc/qcom/mdt_loader.c +++ b/drivers/soc/qcom/mdt_loader.c @@ -83,7 +83,7 @@ ssize_t qcom_mdt_get_size(const struct firmware *fw) int i; ehdr = (struct elf32_hdr *)fw->data; - phdrs = (struct elf32_phdr *)(ehdr + 1); + phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff); for (i = 0; i < ehdr->e_phnum; i++) { phdr = &phdrs[i]; @@ -135,7 +135,7 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len, void *data; ehdr = (struct elf32_hdr *)fw->data; - phdrs = (struct elf32_phdr *)(ehdr + 1); + phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff); if (ehdr->e_phnum < 2) return ERR_PTR(-EINVAL); @@ -215,7 +215,7 @@ int qcom_mdt_pas_init(struct device *dev, const struct firmware *fw, int i; ehdr = (struct elf32_hdr *)fw->data; - phdrs = (struct elf32_phdr *)(ehdr + 1); + phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff); for (i = 0; i < ehdr->e_phnum; i++) { phdr = &phdrs[i]; @@ -270,7 +270,7 @@ static bool qcom_mdt_bins_are_split(const struct firmware *fw, const char *fw_na int i; ehdr = (struct elf32_hdr *)fw->data; - phdrs = (struct elf32_phdr *)(ehdr + 1); + phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff); for (i = 0; i < ehdr->e_phnum; i++) { /* @@ -312,7 +312,7 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw, is_split = qcom_mdt_bins_are_split(fw, fw_name); ehdr = (struct elf32_hdr *)fw->data; - phdrs = (struct elf32_phdr *)(ehdr + 1); + phdrs = (struct elf32_phdr *)(fw->data + ehdr->e_phoff); for (i = 0; i < ehdr->e_phnum; i++) { phdr = &phdrs[i]; -- 2.39.5