9pfs: limit xattr size in xattrcreate

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>
stable-2.8
Greg Kurz 2016-11-01 12:00:40 +01:00
parent 7e55d65c56
commit 3b79ef2cf4
2 changed files with 7 additions and 2 deletions

View File

@ -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;

View File

@ -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"