From 123e44b9a49a42ff5313ec65256f1540d7c52fa0 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 15 Dec 2023 13:24:10 -0700 Subject: cred: switch to using atomic_long_t commit f8fa5d76925991976b3e7076f9d1052515ec1fca upstream. There are multiple ways to grab references to credentials, and the only protection we have against overflowing it is the memory required to do so. With memory sizes only moving in one direction, let's bump the reference count to 64-bit and move it outside the realm of feasibly overflowing. Signed-off-by: Jens Axboe Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/cred.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/cred.h b/include/linux/cred.h index 4b081e4911c8..62509a19ea08 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -114,7 +114,7 @@ static inline int groups_search(const struct group_info *group_info, kgid_t grp) * same context as task->real_cred. */ struct cred { - atomic_t usage; + atomic_long_t usage; #ifdef CONFIG_DEBUG_CREDENTIALS atomic_t subscribers; /* number of processes subscribed */ void *put_addr; @@ -231,7 +231,7 @@ static inline bool cap_ambient_invariant_ok(const struct cred *cred) */ static inline struct cred *get_new_cred(struct cred *cred) { - atomic_inc(&cred->usage); + atomic_long_inc(&cred->usage); return cred; } @@ -275,7 +275,7 @@ static inline void put_cred(const struct cred *_cred) if (cred) { validate_creds(cred); - if (atomic_dec_and_test(&(cred)->usage)) + if (atomic_long_dec_and_test(&(cred)->usage)) __put_cred(cred); } } -- cgit v1.2.3