diff options
author | 2013-05-20 23:05:15 +0530 | |
---|---|---|
committer | 2013-05-28 09:28:42 -0500 | |
commit | 42fe6484c639e8f79e09f81cb89f4f69db224997 (patch) | |
tree | 0522c11fd4f43ca3d52e74fcfa164a91ff165d5f /net/9p/client.c | |
parent | net/9p: Use virtio transpart as the default transport (diff) | |
download | linux-42fe6484c639e8f79e09f81cb89f4f69db224997.tar.gz linux-42fe6484c639e8f79e09f81cb89f4f69db224997.tar.bz2 linux-42fe6484c639e8f79e09f81cb89f4f69db224997.zip |
net/9p: Handle error in zero copy request correctly for 9p2000.u
For zero copy request, error will be encoded in the user space buffer.
So copy the error code correctly using copy_from_user. Here we use the
extra bytes we allocate for zero copy request. If total error details
are more than P9_ZC_HDR_SZ - 7 bytes, we return -EFAULT. The patch also
avoid a memory allocation in the error path.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'net/9p/client.c')
-rw-r--r-- | net/9p/client.c | 55 |
1 files changed, 18 insertions, 37 deletions
diff --git a/net/9p/client.c b/net/9p/client.c index 5e94dabddb68..01f1779eba80 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -562,36 +562,19 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req, if (!p9_is_proto_dotl(c)) { /* Error is reported in string format */ - uint16_t len; - /* 7 = header size for RERROR, 2 is the size of string len; */ - int inline_len = in_hdrlen - (7 + 2); + int len; + /* 7 = header size for RERROR; */ + int inline_len = in_hdrlen - 7; - /* Read the size of error string */ - err = p9pdu_readf(req->rc, c->proto_version, "w", &len); - if (err) - goto out_err; - - ename = kmalloc(len + 1, GFP_NOFS); - if (!ename) { - err = -ENOMEM; + len = req->rc->size - req->rc->offset; + if (len > (P9_ZC_HDR_SZ - 7)) { + err = -EFAULT; goto out_err; } - if (len <= inline_len) { - /* We have error in protocol buffer itself */ - if (pdu_read(req->rc, ename, len)) { - err = -EFAULT; - goto out_free; - } - } else { - /* - * Part of the data is in user space buffer. - */ - if (pdu_read(req->rc, ename, inline_len)) { - err = -EFAULT; - goto out_free; - - } + ename = &req->rc->sdata[req->rc->offset]; + if (len > inline_len) { + /* We have error in external buffer */ if (kern_buf) { memcpy(ename + inline_len, uidata, len - inline_len); @@ -600,19 +583,19 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req, uidata, len - inline_len); if (err) { err = -EFAULT; - goto out_free; + goto out_err; } } } - ename[len] = 0; - if (p9_is_proto_dotu(c)) { - /* For dotu we also have error code */ - err = p9pdu_readf(req->rc, - c->proto_version, "d", &ecode); - if (err) - goto out_free; + ename = NULL; + err = p9pdu_readf(req->rc, c->proto_version, "s?d", + &ename, &ecode); + if (err) + goto out_err; + + if (p9_is_proto_dotu(c)) err = -ecode; - } + if (!err || !IS_ERR_VALUE(err)) { err = p9_errstr2errno(ename, strlen(ename)); @@ -628,8 +611,6 @@ static int p9_check_zc_errors(struct p9_client *c, struct p9_req_t *req, } return err; -out_free: - kfree(ename); out_err: p9_debug(P9_DEBUG_ERROR, "couldn't parse error%d\n", err); return err; |