From 407c928305c1a37232a63811c400ef616f85ccbc Mon Sep 17 00:00:00 2001 From: Stephan Gerhold Date: Mon, 30 Dec 2024 20:59:35 +0100 Subject: [PATCH] soc: qcom: socinfo: Avoid out of bounds read of serial number commit 22cf4fae6660b6e1a583a41cbf84e3046ca9ccd0 upstream. On MSM8916 devices, the serial number exposed in sysfs is constant and does not change across individual devices. It's always: db410c:/sys/devices/soc0$ cat serial_number 2644893864 The firmware used on MSM8916 exposes SOCINFO_VERSION(0, 8), which does not have support for the serial_num field in the socinfo struct. There is an existing check to avoid exposing the serial number in that case, but it's not correct: When checking the item_size returned by SMEM, we need to make sure the *end* of the serial_num is within bounds, instead of comparing with the *start* offset. The serial_number currently exposed on MSM8916 devices is just an out of bounds read of whatever comes after the socinfo struct in SMEM. Fix this by changing offsetof() to offsetofend(), so that the size of the field is also taken into account. Cc: stable@vger.kernel.org Fixes: efb448d0a3fc ("soc: qcom: Add socinfo driver") Signed-off-by: Stephan Gerhold Reviewed-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20241230-qcom-socinfo-serialno-oob-v1-1-9b7a890da3da@linaro.org Signed-off-by: Bjorn Andersson Signed-off-by: Greg Kroah-Hartman --- drivers/soc/qcom/socinfo.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/soc/qcom/socinfo.c b/drivers/soc/qcom/socinfo.c index ecfd3da9d5e8..c2f2a1ce4194 100644 --- a/drivers/soc/qcom/socinfo.c +++ b/drivers/soc/qcom/socinfo.c @@ -789,7 +789,7 @@ static int qcom_socinfo_probe(struct platform_device *pdev) if (!qs->attr.soc_id || !qs->attr.revision) return -ENOMEM; - if (offsetof(struct socinfo, serial_num) <= item_size) { + if (offsetofend(struct socinfo, serial_num) <= item_size) { qs->attr.serial_number = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%u", le32_to_cpu(info->serial_num));