forked from luck/tmp_suning_uos_patched
4047aa909c
xdr_buf_read_mic() tries to find unused contiguous space in a received xdr_buf in order to linearize the checksum for the call to gss_verify_mic. However, the corner cases in this code are numerous and we seem to keep missing them. I've just hit yet another buffer overrun related to it. This overrun is at the end of xdr_buf_read_mic(): 1284 if (buf->tail[0].iov_len != 0) 1285 mic->data = buf->tail[0].iov_base + buf->tail[0].iov_len; 1286 else 1287 mic->data = buf->head[0].iov_base + buf->head[0].iov_len; 1288 __read_bytes_from_xdr_buf(&subbuf, mic->data, mic->len); 1289 return 0; This logic assumes the transport has set the length of the tail based on the size of the received message. base + len is then supposed to be off the end of the message but still within the actual buffer. In fact, the length of the tail is set by the upper layer when the Call is encoded so that the end of the tail is actually the end of the allocated buffer itself. This causes the logic above to set mic->data to point past the end of the receive buffer. The "mic->data = head" arm of this if statement is no less fragile. As near as I can tell, this has been a problem forever. I'm not sure that minimizing au_rslack recently changed this pathology much. So instead, let's use a more straightforward approach: kmalloc a separate buffer to linearize the checksum. This is similar to how gss_validate() currently works. Coming back to this code, I had some trouble understanding what was going on. So I've cleaned up the variable naming and added a few comments that point back to the XDR definition in RFC 2203 to help guide future spelunkers, including myself. As an added clean up, the functionality that was in xdr_buf_read_mic() is folded directly into gss_unwrap_resp_integ(), as that is its only caller. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> |
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| .. | ||
| auth_gss | ||
| xprtrdma | ||
| addr.c | ||
| auth_null.c | ||
| auth_unix.c | ||
| auth.c | ||
| backchannel_rqst.c | ||
| cache.c | ||
| clnt.c | ||
| debugfs.c | ||
| Kconfig | ||
| Makefile | ||
| netns.h | ||
| rpc_pipe.c | ||
| rpcb_clnt.c | ||
| sched.c | ||
| socklib.c | ||
| stats.c | ||
| sunrpc_syms.c | ||
| sunrpc.h | ||
| svc_xprt.c | ||
| svc.c | ||
| svcauth_unix.c | ||
| svcauth.c | ||
| svcsock.c | ||
| sysctl.c | ||
| timer.c | ||
| xdr.c | ||
| xprt.c | ||
| xprtmultipath.c | ||
| xprtsock.c | ||