From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 911723D75BA for ; Mon, 27 Apr 2026 15:48:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777304892; cv=none; b=rI+rLby7QOmBcuo/RG61Uxa2iHMQAOFx7HmM/3Bk6auSUNOyCja3mEv7q5BoTE35WI+kUNit6t9HMxo5Z0uOZBaSYhgrlS1aGJ3unesfQqehU+UmvNtE957bYuVP3Ci9j9DvjSDLhw3+T7i1y08GsT6UZdbD2dZJtrjNhZmwb+I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777304892; c=relaxed/simple; bh=ZGvl6pwK8hhI6Z7/+zjDuc7j0IK6cFQmA5My4ZDgo6s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XCIB8J3mV5c2A/VbTTSzsf/9fBOXfP0F5Oi9Yui9EIjdI6Oigcyg5N3pDLMnm880t+1vOn0XFxcmxL2zqjp66nYgtp5xewgzSt0qlfoOmO3FG9mZK1iGKrHNucoRujX1AY3cDpKsRnWgDHjaJhcLFn8GkmyPOCDGIrBpRo035kI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=RIQPWyeL; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="RIQPWyeL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1777304889; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=k8mwXPbUAnJI1Gm/W783qf7sgkpvXeGSln2ciNPV49w=; b=RIQPWyeLuxV1VZgEAp3ZqVolAqa2DiOhOA+uS81UrPBwn+CDiMcOfTtTEXWlyem6RZgjw/ urIobXrYHvJFQ/3AaRIzKcHQ+asckA2HdSgW5ihgxUl6nNcHLfwzDhpQZOQ2XXqfoF6lYx jx4rRsPLmEEGaIVrGwfwget5knul98M= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-300-j5TdZ1OYN0mrz3ghpZriCA-1; Mon, 27 Apr 2026 11:48:06 -0400 X-MC-Unique: j5TdZ1OYN0mrz3ghpZriCA-1 X-Mimecast-MFC-AGG-ID: j5TdZ1OYN0mrz3ghpZriCA_1777304885 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DB55919560B9; Mon, 27 Apr 2026 15:48:04 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.44.32.126]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id DF56C19560AB; Mon, 27 Apr 2026 15:48:01 +0000 (UTC) From: David Howells To: Christian Brauner Cc: David Howells , Paulo Alcantara , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Matthew Wilcox Subject: [PATCH v4 17/22] netfs: Fix potential uninitialised var in netfs_extract_user_iter() Date: Mon, 27 Apr 2026 16:46:32 +0100 Message-ID: <20260427154639.180684-18-dhowells@redhat.com> In-Reply-To: <20260427154639.180684-1-dhowells@redhat.com> References: <20260427154639.180684-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 In netfs_extract_user_iter(), if it's given a zero-length iterator, it will fall through the loop without setting ret, and so the error handling behaviour will be undefined, depending on whether ret happens to be negative. The value of ret then propagates back up the callstack. Fix this by presetting ret to 0. Fixes: 85dd2c8ff368 ("netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells cc: Paulo Alcantara cc: Matthew Wilcox cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org --- fs/netfs/iterator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/netfs/iterator.c b/fs/netfs/iterator.c index adca78747f23..429e4396e1b0 100644 --- a/fs/netfs/iterator.c +++ b/fs/netfs/iterator.c @@ -43,7 +43,7 @@ ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len, unsigned int max_pages; unsigned int npages = 0; unsigned int i; - ssize_t ret; + ssize_t ret = 0; size_t count = orig_len, offset, len; size_t bv_size, pg_size;