linux-kernel - [PATCH v2 08/29] sev-dev: avoid pointless cred reference count bump

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Message-Id: <20241125-work-cred-v2-8-68b9d38bb5b2@kernel.org>
Date: Mon, 25 Nov 2024 15:10:04 +0100
From: Christian Brauner <brauner@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Amir Goldstein <amir73il@...il.com>, Miklos Szeredi <miklos@...redi.hu>, 
 Al Viro <viro@...iv.linux.org.uk>, Jens Axboe <axboe@...nel.dk>, 
 linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org, 
 Christian Brauner <brauner@...nel.org>
Subject: [PATCH v2 08/29] sev-dev: avoid pointless cred reference count
 bump

and fix a memory leak while at it. The new creds are created via
prepare_creds() and then reverted via put_cred(revert_creds()). The
additional reference count bump from override_creds() wasn't even taken
into account before.

Signed-off-by: Christian Brauner <brauner@...nel.org>
---
 drivers/crypto/ccp/sev-dev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 187c34b02442dd50640f88713bc5f6f88a1990f4..2e87ca0e292a1c1706a8e878285159b481b68a6f 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -244,7 +244,7 @@ static struct file *open_file_as_root(const char *filename, int flags, umode_t m
 	if (!cred)
 		return ERR_PTR(-ENOMEM);
 	cred->fsuid = GLOBAL_ROOT_UID;
-	old_cred = override_creds(get_new_cred(cred));
+	old_cred = override_creds(cred);
 
 	fp = file_open_root(&root, filename, flags, mode);
 	path_put(&root);

-- 
2.45.2