From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dominique Martinet , syzbot+d4252148d198410b864f@syzkaller.appspotmail.com Subject: [PATCH 3.18 02/83] v9fs_dir_readdir: fix double-free on p9stat_read error Date: Thu, 29 Nov 2018 15:11:20 +0100 Message-Id: <20181129140138.148067799@linuxfoundation.org> In-Reply-To: <20181129140138.002176596@linuxfoundation.org> References: <20181129140138.002176596@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dominique Martinet commit 81c99089bce693b94b775b6eb888115d2d540086 upstream. p9stat_read will call p9stat_free on error, we should only free the struct content on success. There also is no need to "p9stat_init" st as the read function will zero the whole struct for us anyway, so clean up the code a bit while we are here. Link: http://lkml.kernel.org/r/1535410108-20650-1-git-send-email-asmadeus@codewreck.org Signed-off-by: Dominique Martinet Reported-by: syzbot+d4252148d198410b864f@syzkaller.appspotmail.com Signed-off-by: Greg Kroah-Hartman --- fs/9p/vfs_dir.c | 11 ----------- 1 file changed, 11 deletions(-) --- a/fs/9p/vfs_dir.c +++ b/fs/9p/vfs_dir.c @@ -75,15 +75,6 @@ static inline int dt_type(struct p9_wsta return rettype; } -static void p9stat_init(struct p9_wstat *stbuf) -{ - stbuf->name = NULL; - stbuf->uid = NULL; - stbuf->gid = NULL; - stbuf->muid = NULL; - stbuf->extension = NULL; -} - /** * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir * @filp: opened file structure @@ -136,12 +127,10 @@ static int v9fs_dir_readdir(struct file rdir->tail = err; } while (rdir->head < rdir->tail) { - p9stat_init(&st); err = p9stat_read(fid->clnt, rdir->buf + rdir->head, rdir->tail - rdir->head, &st); if (err) { p9_debug(P9_DEBUG_VFS, "returned %d\n", err); - p9stat_free(&st); return -EIO; } reclen = st.size+2;