From: Eric Biggers <ebigg...@google.com>

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: 0b77f5bfb45c ("keys: make the keyring quotas controllable through 
/proc/sys")
Cc: sta...@vger.kernel.org
Signed-off-by: Eric Biggers <ebigg...@google.com>
Signed-off-by: David Howells <dhowe...@redhat.com>
---

 security/keys/key.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/keys/key.c b/security/keys/key.c
index 44a80d6741a1..0ec9322af4f9 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -265,8 +265,8 @@ struct key *key_alloc(struct key_type *type, const char 
*desc,
 
                spin_lock(&user->lock);
                if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) {
-                       if (user->qnkeys + 1 >= maxkeys ||
-                           user->qnbytes + quotalen >= maxbytes ||
+                       if (user->qnkeys + 1 > maxkeys ||
+                           user->qnbytes + quotalen > maxbytes ||
                            user->qnbytes + quotalen < user->qnbytes)
                                goto no_quota;
                }

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