From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x226AgEUJ7fvq4WPh/1LVN+5yxjKSkWpuV8ph+YTZICDKJ2B8cljmuC/fd/qZp200Yd7y+sn+ ARC-Seal: i=1; a=rsa-sha256; t=1518708869; cv=none; d=google.com; s=arc-20160816; b=UHVzllKruwtYJ3iL+axRP5iHUaJRThLw6dkAzdj4HRXrpPLHerrXs2MSDpqqIahPh3 14b4IpPe44Tc1HDnsRcdgy/458hnbR/9Q/an//1+SlERBjDUFuidEpyv0FxXsqA1L3e8 alLXllc6RQoCY+o5dyZcmO9h36EuzHU7IRmultwaWKDFn923UWC5igafTLCy84kQulCm qkHFTn9u4XI940tNz3JVikNL+q9aIyoS4O9kgIbZ4K765yTgjM4PzjPCyQ7ZjO2RacEs 2JlVUnuT6jUY5/8Nj25FHVIKBWI/ETf7d/kkiZr7Kw1fI8UhcsO6L6w+b9EbKix3lKG0 tPOw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=3BnCAWl2Vlgsk4rpu5FvicQ2lg6TXjtYFU4Ao04oGj4=; b=u/q3Nm5sLdWM/5JnGTs/OQ/LUEFhKCqOYSzVPJW94lQKMR6Y6iulq5VVrUYiWEZ9v9 q/4yjndAOVHbK8w+/w8w9A8Z6ON5n8BU7vpai66TSWIQnuxFJNL9PkayTm7ex/MuCkBg Uks1S+E6eVl7kYO42OpvVKLo9AGAf1elIZQPdGrpLml0Cg9BDziJxBBpg9pOkRaTVJ6T +Ch7S8DULUcLho5vfusBQ1z6Sd4tHcH+Nb4JRAjiO1gw6pvmb3iR+d9OMV0v1nHmsn3V +JNGW4SG5Ed5iuq7R3WGbonEpYeyhhojCkk750mZZstcXG4+vcUia4fQOpFEhogqni2H 0ERw== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tejun Heo , Ivan Vecera , Al Viro Subject: [PATCH 4.14 110/195] kernfs: fix regression in kernfs_fop_write caused by wrong type Date: Thu, 15 Feb 2018 16:16:41 +0100 Message-Id: <20180215151711.205150931@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180215151705.738773577@linuxfoundation.org> References: <20180215151705.738773577@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1592480732716912474?= X-GMAIL-MSGID: =?utf-8?q?1592481671305295388?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ivan Vecera commit ba87977a49913129962af8ac35b0e13e0fa4382d upstream. Commit b7ce40cff0b9 ("kernfs: cache atomic_write_len in kernfs_open_file") changes type of local variable 'len' from ssize_t to size_t. This change caused that the *ppos value is updated also when the previous write callback failed. Mentioned snippet: ... len = ops->write(...); <- return value can be negative ... if (len > 0) <- true here in this case *ppos += len; ... Fixes: b7ce40cff0b9 ("kernfs: cache atomic_write_len in kernfs_open_file") Acked-by: Tejun Heo Signed-off-by: Ivan Vecera Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -275,7 +275,7 @@ static ssize_t kernfs_fop_write(struct f { struct kernfs_open_file *of = kernfs_of(file); const struct kernfs_ops *ops; - size_t len; + ssize_t len; char *buf; if (of->atomic_write_len) {