From: Yang Xu xuyang2018.jy@cn.fujitsu.com
stable inclusion from linux-4.19.116 commit 14b96359440421c4d84033933a2a5de73de1510d
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commit 2e356101e72ab1361821b3af024d64877d9a798d upstream.
Currently, when we add a new user key, the calltrace as below:
add_key() key_create_or_update() key_alloc() __key_instantiate_and_link generic_key_instantiate key_payload_reserve ......
Since commit a08bf91ce28e ("KEYS: allow reaching the keys quotas exactly"), we can reach max bytes/keys in key_alloc, but we forget to remove this limit when we reserver space for payload in key_payload_reserve. So we can only reach max keys but not max bytes when having delta between plen and type->def_datalen. Remove this limit when instantiating the key, so we can keep consistent with key_alloc.
Also, fix the similar problem in keyctl_chown_key().
Fixes: 0b77f5bfb45c ("keys: make the keyring quotas controllable through /proc/sys") Fixes: a08bf91ce28e ("KEYS: allow reaching the keys quotas exactly") Cc: stable@vger.kernel.org # 5.0.x Cc: Eric Biggers ebiggers@google.com Signed-off-by: Yang Xu xuyang2018.jy@cn.fujitsu.com Reviewed-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Reviewed-by: Eric Biggers ebiggers@google.com Signed-off-by: Jarkko Sakkinen jarkko.sakkinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- security/keys/key.c | 2 +- security/keys/keyctl.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/security/keys/key.c b/security/keys/key.c index 749a5cf27a19..d5fa8c4fc554 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -383,7 +383,7 @@ int key_payload_reserve(struct key *key, size_t datalen) spin_lock(&key->user->lock);
if (delta > 0 && - (key->user->qnbytes + delta >= maxbytes || + (key->user->qnbytes + delta > maxbytes || key->user->qnbytes + delta < key->user->qnbytes)) { ret = -EDQUOT; } diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index edbbc5055976..9394d72a77e8 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -948,8 +948,8 @@ long keyctl_chown_key(key_serial_t id, uid_t user, gid_t group) key_quota_root_maxbytes : key_quota_maxbytes;
spin_lock(&newowner->lock); - if (newowner->qnkeys + 1 >= maxkeys || - newowner->qnbytes + key->quotalen >= maxbytes || + if (newowner->qnkeys + 1 > maxkeys || + newowner->qnbytes + key->quotalen > maxbytes || newowner->qnbytes + key->quotalen < newowner->qnbytes) goto quota_overrun;