qemu-kvm/SOURCES/kvm-virtiofsd-validate-input-buffer-sizes-in-do_write_bu.patch

138 lines
4.9 KiB
Diff

From 6877a6c456178d6c1ca9a0ffaabaa7e51105b2ac Mon Sep 17 00:00:00 2001
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Mon, 27 Jan 2020 19:01:22 +0100
Subject: [PATCH 051/116] virtiofsd: validate input buffer sizes in
do_write_buf()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: <20200127190227.40942-48-dgilbert@redhat.com>
Patchwork-id: 93501
O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 047/112] virtiofsd: validate input buffer sizes in do_write_buf()
Bugzilla: 1694164
RH-Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Sergio Lopez Pascual <slp@redhat.com>
From: Stefan Hajnoczi <stefanha@redhat.com>
There is a small change in behavior: if fuse_write_in->size doesn't
match the input buffer size then the request is failed. Previously
write requests with 1 fuse_buf element would truncate to
fuse_write_in->size.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit 0ba8c3c6fce8fe949d59c1fd84d98d220ef9e759)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
tools/virtiofsd/fuse_lowlevel.c | 49 +++++++++++++++++++++++++----------------
1 file changed, 30 insertions(+), 19 deletions(-)
diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c
index 7e10995..611e8b0 100644
--- a/tools/virtiofsd/fuse_lowlevel.c
+++ b/tools/virtiofsd/fuse_lowlevel.c
@@ -1003,8 +1003,8 @@ static void do_write(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
}
}
-static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg,
- struct fuse_bufvec *ibufv)
+static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid,
+ struct fuse_mbuf_iter *iter, struct fuse_bufvec *ibufv)
{
struct fuse_session *se = req->se;
struct fuse_bufvec *pbufv = ibufv;
@@ -1012,28 +1012,27 @@ static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg,
.buf[0] = ibufv->buf[0],
.count = 1,
};
- struct fuse_write_in *arg = (struct fuse_write_in *)inarg;
+ struct fuse_write_in *arg;
+ size_t arg_size = sizeof(*arg);
struct fuse_file_info fi;
memset(&fi, 0, sizeof(fi));
+
+ arg = fuse_mbuf_iter_advance(iter, arg_size);
+ if (!arg) {
+ fuse_reply_err(req, EINVAL);
+ return;
+ }
+
+ fi.lock_owner = arg->lock_owner;
+ fi.flags = arg->flags;
fi.fh = arg->fh;
fi.writepage = arg->write_flags & FUSE_WRITE_CACHE;
if (ibufv->count == 1) {
- fi.lock_owner = arg->lock_owner;
- fi.flags = arg->flags;
- if (!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD)) {
- tmpbufv.buf[0].mem = PARAM(arg);
- }
- tmpbufv.buf[0].size -=
- sizeof(struct fuse_in_header) + sizeof(struct fuse_write_in);
- if (tmpbufv.buf[0].size < arg->size) {
- fuse_log(FUSE_LOG_ERR,
- "fuse: do_write_buf: buffer size too small\n");
- fuse_reply_err(req, EIO);
- return;
- }
- tmpbufv.buf[0].size = arg->size;
+ assert(!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD));
+ tmpbufv.buf[0].mem = ((char *)arg) + arg_size;
+ tmpbufv.buf[0].size -= sizeof(struct fuse_in_header) + arg_size;
pbufv = &tmpbufv;
} else {
/*
@@ -1043,6 +1042,13 @@ static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg,
ibufv->buf[0].size = 0;
}
+ if (fuse_buf_size(pbufv) != arg->size) {
+ fuse_log(FUSE_LOG_ERR,
+ "fuse: do_write_buf: buffer size doesn't match arg->size\n");
+ fuse_reply_err(req, EIO);
+ return;
+ }
+
se->op.write_buf(req, nodeid, pbufv, arg->offset, &fi);
}
@@ -2052,12 +2058,17 @@ void fuse_session_process_buf_int(struct fuse_session *se,
struct fuse_chan *ch)
{
const struct fuse_buf *buf = bufv->buf;
+ struct fuse_mbuf_iter iter = FUSE_MBUF_ITER_INIT(buf);
struct fuse_in_header *in;
const void *inarg;
struct fuse_req *req;
int err;
- in = buf->mem;
+ /* The first buffer must be a memory buffer */
+ assert(!(buf->flags & FUSE_BUF_IS_FD));
+
+ in = fuse_mbuf_iter_advance(&iter, sizeof(*in));
+ assert(in); /* caller guarantees the input buffer is large enough */
if (se->debug) {
fuse_log(FUSE_LOG_DEBUG,
@@ -2129,7 +2140,7 @@ void fuse_session_process_buf_int(struct fuse_session *se,
inarg = (void *)&in[1];
if (in->opcode == FUSE_WRITE && se->op.write_buf) {
- do_write_buf(req, in->nodeid, inarg, bufv);
+ do_write_buf(req, in->nodeid, &iter, bufv);
} else {
fuse_ll_ops[in->opcode].func(req, in->nodeid, inarg);
}
--
1.8.3.1