@@ -1482,7 +1482,7 @@ static void v9fs_walk_complete(V9fsState *s, V9fsWalkState *vs, int err)
{
complete_pdu(s, vs->pdu, err);
- if (vs->nwnames) {
+ if (vs->nwnames && vs->nwnames <= P9_MAXWELEM) {
for (vs->name_idx = 0; vs->name_idx < vs->nwnames; vs->name_idx++) {
v9fs_string_free(&vs->wnames[vs->name_idx]);
}
@@ -1578,7 +1578,7 @@ static void v9fs_walk(V9fsState *s, V9fsPDU *pdu)
vs->offset += pdu_unmarshal(vs->pdu, vs->offset, "ddw", &fid,
&newfid, &vs->nwnames);
- if (vs->nwnames) {
+ if (vs->nwnames && vs->nwnames <= P9_MAXWELEM) {
vs->wnames = qemu_mallocz(sizeof(vs->wnames[0]) * vs->nwnames);
vs->qids = qemu_mallocz(sizeof(vs->qids[0]) * vs->nwnames);
@@ -1587,6 +1587,9 @@ static void v9fs_walk(V9fsState *s, V9fsPDU *pdu)
vs->offset += pdu_unmarshal(vs->pdu, vs->offset, "s",
&vs->wnames[i]);
}
+ } else if (vs->nwnames > P9_MAXWELEM) {
+ err = -EINVAL;
+ goto out;
}
vs->fidp = lookup_fid(s, fid);
@@ -282,7 +282,7 @@ typedef struct V9fsStatStateDotl {
typedef struct V9fsWalkState {
V9fsPDU *pdu;
size_t offset;
- int16_t nwnames;
+ uint16_t nwnames;
int name_idx;
V9fsQID *qids;
V9fsFidState *fidp;
The nwnames field in TWALK message is assumed to be >=0 and <= MAXWELEM which is defined as macro P9_MAXWELEM (16) in virtio-9p.h as per 9p2000 RFC. Appropriate changes are required in V9fsWalkState and v9fs_walk. v4: - rebased on mainline repo, else condition updated as required. v3: - Updated if-else conditions to appropriately handle nwnames = 0. v2: - Added check in v9fs_walk_complete as well. Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com> --- hw/virtio-9p.c | 7 +++++-- hw/virtio-9p.h | 2 +- 2 files changed, 6 insertions(+), 3 deletions(-)