In the Linux kernel, the following vulnerability has been resolved:
rcu: Fix buffer overflow in printcpustall_info()
The rcuc-starvation output from printcpustall_info() might overflow the buffer if there is a huge difference in jiffies difference. The situation might seem improbable, but computers sometimes get very confused about time, which can result in full-sized integers, and, in this case, buffer overflow.
Also, the unsigned jiffies difference is printed using %ld, which is normally for signed integers. This is intentional for debugging purposes, but it is not obvious from the code.
This commit therefore changes sprintf() to snprintf() and adds a clarifying comment about intention of %ld format.
Found by Linux Verification Center (linuxtesting.org) with SVACE.