diff options
author | Jan Dakinevich <jan.dakinevich@gmail.com> | 2017-09-20 08:48:52 +0200 |
---|---|---|
committer | Greg Kurz <groug@kaod.org> | 2017-09-20 08:48:52 +0200 |
commit | 772a73692ecb52bace0cff6f95df62f59b8cabe0 (patch) | |
tree | 64216246ad36d3af41ad089c18652301cfa62315 | |
parent | 4d8bc7334b06ef01a21cad3d1eb8dc183037a06b (diff) | |
download | qemu-772a73692ecb52bace0cff6f95df62f59b8cabe0.zip qemu-772a73692ecb52bace0cff6f95df62f59b8cabe0.tar.gz qemu-772a73692ecb52bace0cff6f95df62f59b8cabe0.tar.bz2 |
9pfs: check the size of transport buffer before marshaling
v9fs_do_readdir_with_stat() should check for a maximum buffer size
before an attempt to marshal gathered data. Otherwise, buffers assumed
as misconfigured and the transport would be broken.
The patch brings v9fs_do_readdir_with_stat() in conformity with
v9fs_do_readdir() behavior.
Signed-off-by: Jan Dakinevich <jan.dakinevich@gmail.com>
[groug, regression caused my commit 8d37de41cab1 # 2.10]
Signed-off-by: Greg Kurz <groug@kaod.org>
-rw-r--r-- | hw/9pfs/9p.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index cdd44bd..23ac7bb 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -1748,17 +1748,26 @@ static int coroutine_fn v9fs_do_readdir_with_stat(V9fsPDU *pdu, if (err < 0) { break; } + if ((count + v9stat.size + 2) > max_count) { + v9fs_readdir_unlock(&fidp->fs.dir); + + /* Ran out of buffer. Set dir back to old position and return */ + v9fs_co_seekdir(pdu, fidp, saved_dir_pos); + v9fs_stat_free(&v9stat); + v9fs_path_free(&path); + return count; + } + /* 11 = 7 + 4 (7 = start offset, 4 = space for storing count) */ len = pdu_marshal(pdu, 11 + count, "S", &v9stat); v9fs_readdir_unlock(&fidp->fs.dir); - if ((len != (v9stat.size + 2)) || ((count + len) > max_count)) { - /* Ran out of buffer. Set dir back to old position and return */ + if (len < 0) { v9fs_co_seekdir(pdu, fidp, saved_dir_pos); v9fs_stat_free(&v9stat); v9fs_path_free(&path); - return count; + return len; } count += len; v9fs_stat_free(&v9stat); |