Created attachment 1116893 [details]
[patch] fix command line parsing

I noticed an out of bounds read access in keyctl when compiling it with
address sanitizer (add -fsanitize=address to cflags).

I figured out it was the code for parsing the command line, here:
        for (cmd = commands; cmd->name; cmd++) {
                if (!cmd->action)
                        continue;
                if (strlen(cmd->name) > n)
                        continue;
                if (memcmp(cmd->name, *argv, n) != 0)
                        continue;

The strlen(cmd->name) > n comparison seems wrong, it must be <. Because
when the cmd->name is shorter than argv there never can be a partial
match, if it is larger then there can be. This error causes the memcmp
command to read invalid memory.

(I reported this a while back directly to the maintainer via email, but received no reply. The last release of keyutils was in 2014.)