[PATCH v2 21/29] smb: avoid pointless cred reference count bump

Christian Brauner
2024-11-25T14:11:09Z

The creds are allocated via prepare_kernel_cred() which has already
taken a reference.

This also removes a pointless check that gives the impression that
override_creds() can ever be called on a task with current->cred NULL.
That's not possible afaict. Remove the check to not imply that there can
be a dangling pointer in current->cred.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
fs/smb/server/smb_common.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c
index f1d770a214c8b2c7d7dd4083ef57c7130bbce52c..a92e3081cead250dac89a0dc00fcee8444465b8a 100644
--- a/fs/smb/server/smb_common.c
+++ b/fs/smb/server/smb_common.c
@@ -780,11 +780,7 @@ int __ksmbd_override_fsids(struct ksmbd_work *work,
cred->cap_effective = cap_drop_fs_set(cred->cap_effective);

WARN_ON(work->saved_cred);
- work->saved_cred = override_creds(get_new_cred(cred));
- if (!work->saved_cred) {
- abort_creds(cred);
- return -EINVAL;
- }
+ work->saved_cred = override_creds(cred);
return 0;
}

@@ -796,13 +792,11 @@ int ksmbd_override_fsids(struct ksmbd_work *work)
void ksmbd_revert_fsids(struct ksmbd_work *work)
{
const struct cred *cred;
-
WARN_ON(!work->saved_cred);

- cred = current_cred();
- put_cred(revert_creds(work->saved_cred));
- put_cred(cred);
+ cred = revert_creds(work->saved_cred);
work->saved_cred = NULL;
+ put_cred(cred);
}

__le32 smb_map_generic_desired_access(__le32 daccess)

--
2.45.2