Messages in this thread Patch in this message | | | Subject | [PATCH 1/4] KEYS: allow reaching the keys quotas exactly | From | David Howells <> | Date | Thu, 14 Feb 2019 16:19:16 +0000 |
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From: Eric Biggers <ebiggers@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: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@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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