If the sysctl 'kernel.keys.maxkeys' is set to some number n, then
actually users can only add up to 'n - 1' keys. Likewise for
'kernel.keys.maxbytes' and the root_* versions of these sysctls. But
these sysctls are apparently supposed to be *maximums*, as per their
names and all documentation I could find -- the keyrings(7) man page,
Documentation/security/keys/core.rst, and all the mentions of EDQUOT
meaning that the key quota was *exceeded* (as opposed to reached).
Thus, fix the code to allow reaching the quotas exactly.
Fixes: 0b77f5bfb4 ("keys: make the keyring quotas controllable through /proc/sys")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
a08bf91ce2