On 2023/2/4 1:10, David Hildenbrand wrote: > On 28.01.23 07:32, Wupeng Ma wrote: >> From: Ma Wupeng <mawupeng1@xxxxxxxxxx> >> >> While testing mlock, we have a problem if the len of mlock is ULONG_MAX. >> The return value of mlock is zero. But nothing will be locked since the >> len in do_mlock overflows to zero due to the following code in mlock: >> >> len = PAGE_ALIGN(len + (offset_in_page(start))); >> >> The same problem happens in munlock. >> >> Add new check and return -EINVAL to fix this overflowing scenarios since >> they are absolutely wrong. >> >> Similar logic is used to fix problems with multiple syscalls. >> >> Changelog since v2[2]: >> - modified the way of checking overflows based on Andrew's comments >> >> Changelog since v1[1]: >> - only check overflow rather than access_ok to keep backward-compatibility > > Do you have some test cases and could we add them to LTP, for example? The basic idea is setting param len to ULONG_MAX. while will overflow if PAGE_ALIGN(len). Here are some simple examples: mlock(addr, ULONG_MAX); set_mempolicy_home_node(addr, ULONG_MAX, 0, 0); mbind(addr, ULONG_MAX, MPOL_BIND, &nodemask, max_node, MPOL_MF_MOVE_ALL); msync(addr, ULONG_MAX, MS_ASYNC); >
