From 5cab6121156eeaa5c4c839775bcb7df74d584a33 Mon Sep 17 00:00:00 2001 From: Sergey Shtylyov Date: Fri, 21 Jun 2024 10:35:47 +0800 Subject: [PATCH] of: module: add buffer overflow check in of_modalias() mainline inclusion from mainline-v6.10-rc1 commit cf7385cb26ac4f0ee6c7385960525ad534323252 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6SDQ CVE: CVE-2024-38541 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cf7385cb26ac4f0ee6c7385960525ad534323252 --------------------------- In of_modalias(), if the buffer happens to be too small even for the 1st snprintf() call, the len parameter will become negative and str parameter (if not NULL initially) will point beyond the buffer's end. Add the buffer overflow check after the 1st snprintf() call and fix such check after the strlen() call (accounting for the terminating NUL char). Fixes: bc575064d688 ("of/device: use of_property_for_each_string to parse compatible strings") Signed-off-by: Sergey Shtylyov Link: https://lore.kernel.org/r/bbfc6be0-c687-62b6-d015-5141b93f313e@omp.ru Signed-off-by: Rob Herring Conflicts: drivers/of/module.c [of_modalias() was in drivers/of/device.c before commit bd7a7ed774af ("of: Move of_modalias() to module.c") and was named as of_device_get_modalias() before commit 5c3d15e127eb ("of: Update of_device_get_modalias()"). Both commits are in v6.4.] Signed-off-by: GONG, Ruiqi --- drivers/of/device.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/of/device.c b/drivers/of/device.c index 3a547793135c..93f08f18f6b3 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -231,14 +231,15 @@ static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T', of_node_get_device_type(dev->of_node)); tsize = csize; + if (csize >= len) + csize = len > 0 ? len - 1 : 0; len -= csize; - if (str) - str += csize; + str += csize; of_property_for_each_string(dev->of_node, "compatible", p, compat) { csize = strlen(compat) + 1; tsize += csize; - if (csize > len) + if (csize >= len) continue; csize = snprintf(str, len, "C%s", compat); -- Gitee