[PATCH 5.10 06/29] Revert "ucounts: Increase ucounts reference counter before the security hook"

Greg Kroah-Hartman
2021-09-06T12:57:08Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit b493af3a66e067f93e5e03465507866ddeabff9e which is
commit bbb6d0f3e1feb43d663af089c7dedb23be6a04fb upstream.

The "original" commit 905ae01c4ae2 ("Add a reference to ucounts for each
cred"), should not have been applied to the 5.10.y tree, so revert it,
and the follow-on fixup patches as well.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/87v93k4bl6.fsf@disp2133
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/cred.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -286,11 +286,11 @@ struct cred *prepare_creds(void)
new->security = NULL;
#endif

- new->ucounts = get_ucounts(new->ucounts);
- if (!new->ucounts)
+ if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
goto error;

- if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
+ new->ucounts = get_ucounts(new->ucounts);
+ if (!new->ucounts)
goto error;

validate_creds(new);
@@ -753,11 +753,11 @@ struct cred *prepare_kernel_cred(struct
#ifdef CONFIG_SECURITY
new->security = NULL;
#endif
- new->ucounts = get_ucounts(new->ucounts);
- if (!new->ucounts)
+ if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
goto error;

- if (security_prepare_creds(new, old, GFP_KERNEL_ACCOUNT) < 0)
+ new->ucounts = get_ucounts(new->ucounts);
+ if (!new->ucounts)
goto error;

put_cred(old);