| Message ID | bbfc6be0-c687-62b6-d015-5141b93f313e@omp.ru |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [RESEND] of: module: add buffer overflow check in of_modalias() | expand |
| Context | Check | Description |
|---|---|---|
| robh/checkpatch | warning | total: 0 errors, 1 warnings, 18 lines checked |
| robh/patch-applied | fail | build log |
On Sun, Apr 14, 2024 at 11:51:39AM +0300, Sergey Shtylyov wrote: > 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 <s.shtylyov@omp.ru> > > --- > The patch is against the dt/linus branch of Rob Herring's linux.git repo... > > drivers/of/module.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) Applied, thanks.
Index: linux/drivers/of/module.c =================================================================== --- linux.orig/drivers/of/module.c +++ linux/drivers/of/module.c @@ -29,14 +29,15 @@ ssize_t of_modalias(const struct device_ csize = snprintf(str, len, "of:N%pOFn%c%s", np, 'T', of_node_get_device_type(np)); tsize = csize; + if (csize >= len) + csize = len > 0 ? len - 1 : 0; len -= csize; - if (str) - str += csize; + str += csize; of_property_for_each_string(np, "compatible", p, compat) { csize = strlen(compat) + 1; tsize += csize; - if (csize > len) + if (csize >= len) continue; csize = snprintf(str, len, "C%s", compat);
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 <s.shtylyov@omp.ru> --- The patch is against the dt/linus branch of Rob Herring's linux.git repo... drivers/of/module.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)