Messages in this thread Patch in this message | | | From | Alexander Shishkin <> | Subject | [PATCH v3 7/9] stm class: Prevent user-controllable allocations | Date | Tue, 22 Dec 2015 17:25:21 +0200 |
| |
Currently, the character device write method allocates a temporary buffer for user's data, but the user's data size is not sanitized and can cause arbitrarily large allocations via kzalloc() or an integer overflow that will then result in overwriting kernel memory.
This patch trims the input buffer size to avoid these issues.
Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> --- drivers/hwtracing/stm/core.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index 40a8b79ab7..aef8ddb244 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -406,6 +406,9 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf, char *kbuf; int err; + if (count + 1 > PAGE_SIZE) + count = PAGE_SIZE - 1; + /* * if no m/c have been assigned to this writer up to this * point, use "default" policy entry -- 2.6.4
| |