diff mbox

[PULL,v2,for-2.8,4/7] 9pfs: limit xattr size in xattrcreate

Message ID 1478001656-5766-5-git-send-email-groug@kaod.org
State New
Headers show

Commit Message

Greg Kurz Nov. 1, 2016, noon UTC 
We shouldn't allow guests to create extended attribute with arbitrary sizes.
On linux hosts, the limit is XATTR_SIZE_MAX. Let's use it.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 hw/9pfs/9p.c         | 7 ++++++-
 hw/9pfs/trace-events | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 7705ead4b2ac..27af0072599a 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -3247,7 +3247,7 @@  static void coroutine_fn v9fs_xattrcreate(void *opaque)
 {
     int flags;
     int32_t fid;
-    int64_t size;
+    uint64_t size;
     ssize_t err = 0;
     V9fsString name;
     size_t offset = 7;
@@ -3262,6 +3262,11 @@  static void coroutine_fn v9fs_xattrcreate(void *opaque)
     }
     trace_v9fs_xattrcreate(pdu->tag, pdu->id, fid, name.data, size, flags);
 
+    if (size > XATTR_SIZE_MAX) {
+        err = -E2BIG;
+        goto out_nofid;
+    }
+
     file_fidp = get_fid(pdu, fid);
     if (file_fidp == NULL) {
         err = -EINVAL;
diff --git a/hw/9pfs/trace-events b/hw/9pfs/trace-events
index 48d3d8abedb5..fb4de3d465ab 100644
--- a/hw/9pfs/trace-events
+++ b/hw/9pfs/trace-events
@@ -42,6 +42,6 @@  v9fs_mkdir(uint16_t tag, uint8_t id, int32_t fid, char* name, int mode, uint32_t
 v9fs_mkdir_return(uint16_t tag, uint8_t id, int8_t type, int32_t version, int64_t path, int err) "tag %u id %u qid={type %d version %d path %"PRId64"} err %d"
 v9fs_xattrwalk(uint16_t tag, uint8_t id, int32_t fid, int32_t newfid, char* name) "tag %d id %d fid %d newfid %d name %s"
 v9fs_xattrwalk_return(uint16_t tag, uint8_t id, int64_t size) "tag %d id %d size %"PRId64
-v9fs_xattrcreate(uint16_t tag, uint8_t id, int32_t fid, char* name, int64_t size, int flags) "tag %d id %d fid %d name %s size %"PRId64" flags %d"
+v9fs_xattrcreate(uint16_t tag, uint8_t id, int32_t fid, char* name, uint64_t size, int flags) "tag %d id %d fid %d name %s size %"PRIu64" flags %d"
 v9fs_readlink(uint16_t tag, uint8_t id, int32_t fid) "tag %d id %d fid %d"
 v9fs_readlink_return(uint16_t tag, uint8_t id, char* target) "tag %d id %d name %s"