From patchwork Sat Nov 2 05:08:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 13859946 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 7DE2A1AC8AE; Sat, 2 Nov 2024 05:08:47 +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=1730524129; cv=none; b=Sjn1mflHgxrifsPZ06j0PVB/2ekH5pwyIqJCHp+abE/QzAosF7JhjhVkghgArVCKlGOEPOwaOOckIHdakYfzj9CeV7z9BC0qxWxCyaXvqI4lqn2TwPZ9Yg6LrO04+n6Q6Ao87glHUqS4HX8YTC+DvrwyebgBhCjQn/IljctHwik= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730524129; c=relaxed/simple; bh=sIsbHOCdc77aqOwzZ9NdzfWbaJOX5esYl6OGr+8g17w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bs65So6NS46gMA01gAFBbNAmaIiEJ3BbahXTfGEA7FG4G+po29VYXZKA3bGZRPHuF7ld5cyrMgiXYMKivoXpYV3PVhTYQjMpNAz5LY6nOPsXJhF25r+MJLgwNOLiOjnGiQDgvCFE7ORIf40znZSytPxii1/n9jVtPqXmckyMjRc= 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=a4xaumWi; 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="a4xaumWi" 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=EYGEzTbzCwoX59fmg/fy+A0M2cH27/fC1+I1UrCmDZc=; b=a4xaumWihzxkWK0sSVMGC09NKL /EsiX3Dv1qIhCPhGLJUqveSVG6gtBNZ1U93ayc7VzB9EgmgXdfbFST0I3zU+9qpSPpj/EUeuXlqIx Fnyp/bs4rZTmQ47+xzgW7rRAjr5j8FEseJlNADJiY/fv/BDNRH88f6gSL6KPdvBBzDlVBBsLyjzkk fP/fibZTx0A/vhFAcheY5lQxujutQNbon/Mm236ocUpZruF+bKXt0TmhNhrHVYo7eVv/SeGQ8KH+4 g+uQWinRficKJPYDWd7Q4JFj+CvmXIztzmdlGYHSgtOgVi4dL5DA4p08buP+34xGVLU0PPh/KaS/U hXCzdZ5Q==; Received: from viro by zeniv.linux.org.uk with local (Exim 4.98 #2 (Red Hat Linux)) id 1t76N9-0000000AHmC-3giW; Sat, 02 Nov 2024 05:08:27 +0000 From: Al Viro To: linux-fsdevel@vger.kernel.org Cc: viro@zeniv.linux.org.uk, brauner@kernel.org, cgroups@vger.kernel.org, kvm@vger.kernel.org, netdev@vger.kernel.org, torvalds@linux-foundation.org Subject: [PATCH v3 06/28] do_mq_notify(): saner skb freeing on failures Date: Sat, 2 Nov 2024 05:08:04 +0000 Message-ID: <20241102050827.2451599-6-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241102050827.2451599-1-viro@zeniv.linux.org.uk> References: <20241102050219.GA2450028@ZenIV> <20241102050827.2451599-1-viro@zeniv.linux.org.uk> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Sender: Al Viro cleanup is convoluted enough as it is; it's easier to have early failure outs do explicit kfree_skb(nc), rather than going to contortions needed to reuse the cleanup from late failures. Signed-off-by: Al Viro --- ipc/mqueue.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/ipc/mqueue.c b/ipc/mqueue.c index fd05e3d4f7b6..48640a362637 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -1347,8 +1347,8 @@ static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification) if (copy_from_user(nc->data, notification->sigev_value.sival_ptr, NOTIFY_COOKIE_LEN)) { - ret = -EFAULT; - goto free_skb; + kfree_skb(nc); + return -EFAULT; } /* TODO: add a header? */ @@ -1357,16 +1357,14 @@ static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification) retry: sock = netlink_getsockbyfd(notification->sigev_signo); if (IS_ERR(sock)) { - ret = PTR_ERR(sock); - goto free_skb; + kfree_skb(nc); + return PTR_ERR(sock); } timeo = MAX_SCHEDULE_TIMEOUT; ret = netlink_attachskb(sock, nc, &timeo, NULL); - if (ret == 1) { - sock = NULL; + if (ret == 1) goto retry; - } if (ret) return ret; } @@ -1425,10 +1423,6 @@ static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification) out: if (sock) netlink_detachskb(sock, nc); - else -free_skb: - dev_kfree_skb(nc); - return ret; }