From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [62.89.141.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CB26D22F177; Sat, 29 Nov 2025 17:01:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.89.141.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764435702; cv=none; b=uHcGbN54WTpMvqyMiFdLfAd9/xm7DdqWUdjYvuEUFOhBkX7PqE5eqn8OhxkfKxMPvLTOjRp5hPDb+NAq8oxfrT9i1pP0up3bCv27jmsZ0EeCji9TBf+II0ksJu6LYl7CKtbFFtKMgZi533qx366NC+K9uNHQ9g5K0OWs1t0Fwbk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764435702; c=relaxed/simple; bh=xXjiSJqz9atJbTcDg9W0bbHB5PBDXejQhA3es4Oab4s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HUHnYEhl/y4TFdx4Uc6/wKUCVYWPXZLvEjFVqLLd1vwipx+CSWEc2iCGpCNtTe1aOVEMEdqjpJKzDmdQYj1Ns1A5TUWhCfYwYXnRyH8GJikzDzynOQfqL8uf0loQ3fEgFjTWCW0SgkhjZ8HDMKcfp1hyU6rgZOvubeZbcYCf0NQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk; spf=none smtp.mailfrom=ftp.linux.org.uk; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b=HFl38DU2; arc=none smtp.client-ip=62.89.141.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=ftp.linux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linux.org.uk header.i=@linux.org.uk header.b="HFl38DU2" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=linux.org.uk; s=zeniv-20220401; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=2LzmL8ymMOWR0VR+c5QLErm3uhF2BblZGtoWhaq1f0I=; b=HFl38DU2N8ROp8wh8HImOY03Kb ZjO5ADk0TYtcCEdiinFbMmdoq+Oykw6V8mH6F93CKF1+PghIW8Jp5wrzHSxw+dGGYEzAqZXv+KB6g XKdCQBNl1G2FVGkYukcjB5TJeSy7pj0eR1uSVsJ6RnqFVQM0PU/6+2BLBtkD6EAfveQQ9N9PGCMtt mFODHxoxa0S+HFMcO3rIYFxETYwTJMRPI5OhFpVeaHeXcZWqJerQZCpKPIJtYzEFasCYF2wJ9z+Jv b6kuvFhsbF/1qkmJpnMLN0L5PE3P9dVX6IleLzX7LtxCunoXYNlz77LNKyMl+iap9+w1KP/MmP9cW lgE5LWNQ==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.99 #2 (Red Hat Linux)) id 1vPOKN-00000000dDA-32N8; Sat, 29 Nov 2025 17:01:43 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: torvalds@linux-foundation.org, brauner@kernel.org, jack@suse.cz, mjguzik@gmail.com, paul@paul-moore.com, axboe@kernel.dk, audit@vger.kernel.org, io-uring@vger.kernel.org Subject: [RFC PATCH v2 13/18] getname_flags() massage, part 2 Date: Sat, 29 Nov 2025 17:01:37 +0000 Message-ID: <20251129170142.150639-14-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251129170142.150639-1-viro@zeniv.linux.org.uk> References: <20251129170142.150639-1-viro@zeniv.linux.org.uk> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: Al Viro Take the "long name" case into a helper (getname_long()). In case of failure have the caller deal with freeing the original struct filename. Signed-off-by: Al Viro --- fs/namei.c | 56 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 29 insertions(+), 27 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index bc5fe9732949..62e992e4f152 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -131,6 +131,32 @@ static inline void initname(struct filename *name) atomic_set(&name->refcnt, 1); } +static struct filename *getname_long(struct filename *old, + const char __user *filename) +{ + int len; + /* + * size is chosen that way we to guarantee that + * p->iname[0] is within the same object and that + * p->name can't be equal to p->iname, no matter what. + */ + const size_t size = offsetof(struct filename, iname[1]); + struct filename *p __free(kfree) = kzalloc(size, GFP_KERNEL); + if (unlikely(!p)) + return ERR_PTR(-ENOMEM); + + memmove(old, &old->iname, EMBEDDED_NAME_MAX); + p->name = (char *)old; + len = strncpy_from_user((char *)old + EMBEDDED_NAME_MAX, + filename + EMBEDDED_NAME_MAX, + PATH_MAX - EMBEDDED_NAME_MAX); + if (unlikely(len < 0)) + return ERR_PTR(len); + if (unlikely(len == PATH_MAX - EMBEDDED_NAME_MAX)) + return ERR_PTR(-ENAMETOOLONG); + return no_free_ptr(p); +} + struct filename * getname_flags(const char __user *filename, int flags) { @@ -173,34 +199,10 @@ getname_flags(const char __user *filename, int flags) * userland. */ if (unlikely(len == EMBEDDED_NAME_MAX)) { - const size_t size = offsetof(struct filename, iname[1]); - struct filename *p; - - /* - * size is chosen that way we to guarantee that - * result->iname[0] is within the same object and that - * kname can't be equal to result->iname, no matter what. - */ - p = kzalloc(size, GFP_KERNEL); - if (unlikely(!p)) { - __putname(result); - return ERR_PTR(-ENOMEM); - } - memmove(result, &result->iname, EMBEDDED_NAME_MAX); - kname = (char *)result; - p->name = kname; - len = strncpy_from_user(kname + EMBEDDED_NAME_MAX, - filename + EMBEDDED_NAME_MAX, - PATH_MAX - EMBEDDED_NAME_MAX); - if (unlikely(len < 0)) { - kfree(p); - __putname(result); - return ERR_PTR(len); - } - if (unlikely(len == PATH_MAX - EMBEDDED_NAME_MAX)) { - kfree(p); + struct filename *p = getname_long(result, filename); + if (IS_ERR(p)) { __putname(result); - return ERR_PTR(-ENAMETOOLONG); + return p; } result = p; } -- 2.47.3