[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH] device-tree/kernel: Use memcpy in output_length()
- To: <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- From: Michal Orzel <michal.orzel@xxxxxxx>
- Date: Tue, 22 Jul 2025 09:46:45 +0200
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=lists.xenproject.org smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0)
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=xiBxvP0ulKFVy2knXstA/RqmX83330Ik+q0BkaDar1I=; b=R3vtW0Mjm7A4D8dorVu60L5om9roRgmGx/qcUmvNJjU2DhQpWDk48ruEmtHOhP0zmotUok7kQS+CJdOb5yk55m9MDZxLI+SLEWvmzEk1UdzoR7+chhusKVNwX3Kqzh6dRpgVDfIuPwIHLk7cTksZLr0AonQ9/ayp+DZR4EzvRcKXmncp09lH9/uL1jHM9chMRRw2/MvRnoXBfgLx4Bm1EaS+4RKc99pDxcgv4agYFQ1hVO3BvCb6KC7HNq9DAHCfEpV++UeFmVLr/PCYcLM0vxnSzhAZBehgveSFUrj9LWV64UM+28c2ohhFQUaTjKh+PjGC80u0QNDjzN+uolyA3w==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=BSx3vZ5PyojecJvjsnm8lPwvYuLWaEMmoKgYtPgkmUT2aGQW61/OhImDSRVUh4taof+3/ngKWWcXWe++8XZhQRDbalKrgag+6bpUNx3DdwoEuSNbtz/7o7RsCcNoFd1ec5Nfi82TjI+ziseyVrxo8mLxQcfVBrzkk229BiYg82eGfUK9K1AYK5VlnVdyBNXBw+uElNT+0/eP6EA0sOqgEw0rQzLAm+m63IfNtgDT8ClyJaBwxEZy7JWtqnoTmgSpN5FedsSIui1SCHLY6U0AfyYhPZuSVOWqeb7lE/njir1Mk0u3/gTEHJgOF2brRxgxocW8SvYkVbo/ikbDkhCgpw==
- Cc: Michal Orzel <michal.orzel@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Julien Grall <julien@xxxxxxx>, Bertrand Marquis <bertrand.marquis@xxxxxxx>
- Delivery-date: Tue, 22 Jul 2025 07:47:01 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
Trying to boot a compressed kernel with UBSAN enabled, results in the
following warning:
(XEN) UBSAN: Undefined behaviour in common/device-tree/kernel.c:21:12
(XEN) load of misaligned address 00000a0040f89867 for type 'uint32_t'
(XEN) which requires 4 byte alignment
...
(XEN) [<00000a0000529964>] kernel_decompress+0x2bc/0x5bc
(XEN) [<00000a000052a354>] kernel_probe+0x6f0/0x734
(XEN) [<00000a0000528714>] dom0less-build.c#construct_domU+0x188/0x9d8
If &image[image_len - 4] is not aligned to 4B boundary it causes
unaligned access which is undefined behavior on Arm. Use memcpy instead
to be safe.
Fixes: c1be0b102e0e ("xen/arm: support gzip compressed kernels")
Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
---
xen/common/device-tree/kernel.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/xen/common/device-tree/kernel.c b/xen/common/device-tree/kernel.c
index ef393182b691..28096121a52d 100644
--- a/xen/common/device-tree/kernel.c
+++ b/xen/common/device-tree/kernel.c
@@ -18,7 +18,11 @@
static uint32_t __init output_length(char *image, unsigned long image_len)
{
- return *(uint32_t *)&image[image_len - 4];
+ uint32_t val;
+
+ memcpy(&val, &image[image_len - 4], sizeof(val));
+
+ return val;
}
int __init kernel_decompress(struct boot_module *mod, uint32_t offset)
--
2.43.0
|
