[RFC PATCH 6/8] KEYS: Prevent overflow of user->qnbytes in key_alloc()

[Jarkko Sakkinen]

Add the missing check rejecting resulting byte counts above INT_MAX.

Cc: stable at vger.kernel.org
Assisted-by: LLM
Fixes: 7e047ef5fe2d ("[PATCH] keys: sort out key quota system")
Signed-off-by: Jarkko Sakkinen <jarkko at kernel.org>
---
 security/keys/key.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/security/keys/key.c b/security/keys/key.c
index 18043251365f..5afc16425daf 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -263,7 +263,8 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 			key_quota_root_maxbytes : key_quota_maxbytes;
 
 		spin_lock_irqsave(&user->lock, irqflags);
-		if (user->qnkeys == INT_MAX)
+		if (user->qnkeys == INT_MAX ||
+		    quotalen > INT_MAX - user->qnbytes)
 			goto no_quota;
 
 		if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) {
-- 
2.47.3