From: Dominique Martinet <asmadeus@codewreck.org>
To: v9fs-developer@lists.sourceforge.net
Cc: Dominique Martinet <dominique.martinet@cea.fr>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
syzkaller-bugs@googlegroups.com,
Eric Van Hensbergen <ericvh@gmail.com>,
Latchesar Ionkov <lucho@ionkov.net>
Subject: [PATCH 1/2] v9fs_dir_readdir: fix double-free on p9stat_read error
Date: Tue, 28 Aug 2018 00:48:27 +0200 [thread overview]
Message-ID: <1535410108-20650-1-git-send-email-asmadeus@codewreck.org> (raw)
In-Reply-To: <000000000000af648b057456e234@google.com>
From: Dominique Martinet <dominique.martinet@cea.fr>
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.
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Reported-by: syzbot+d4252148d198410b864f@syzkaller.appspotmail.com
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
---
fs/9p/vfs_dir.c | 11 -----------
1 file changed, 11 deletions(-)
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index b0405d6aac85..48db9a9f13f9 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -76,15 +76,6 @@ static inline int dt_type(struct p9_wstat *mistat)
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
@@ -145,12 +136,10 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
rdir->tail = n;
}
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;
--
2.17.1
next prev parent reply other threads:[~2018-08-27 22:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-26 13:50 KASAN: invalid-free in p9stat_free syzbot
2018-08-27 5:24 ` Dominique Martinet
2018-08-27 14:25 ` Dmitry Vyukov
2018-08-27 22:40 ` Dominique Martinet
2018-08-27 22:48 ` Dominique Martinet [this message]
2018-08-27 22:48 ` [PATCH 2/2] 9p: clear dangling pointers " Dominique Martinet
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