gwj / at91sam9263 · Commits

Commit 74efd61a75f1a400aa480ad08231ba31ccdec895

Authored by Jan Kiszka
Committed by Anthony Liguori
1 parent 229609dd

slirp: tftp: Relax filename format check 

[ Applies on top of my recently posted slirp series. ]

Allow tftp requests with filenames that do not start with a slash.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Inline Side-by-side
Showing 1 changed file with 5 additions and 3 deletions
slirp/tftp.c
  View file @74efd61
... ... @@ -284,11 +284,12 @@ static void tftp_handle_rrq(Slirp *slirp, struct tftp_t *tp, int pktlen)
284 284  
285 285 /* prepend tftp_prefix */
286 286 prefix_len = strlen(slirp->tftp_prefix);
287   - spt->filename = qemu_malloc(prefix_len + TFTP_FILENAME_MAX + 1);
  287 + spt->filename = qemu_malloc(prefix_len + TFTP_FILENAME_MAX + 2);
288 288 memcpy(spt->filename, slirp->tftp_prefix, prefix_len);
  289 + spt->filename[prefix_len] = '/';
289 290  
290 291 /* get name */
291   - req_fname = spt->filename + prefix_len;
  292 + req_fname = spt->filename + prefix_len + 1;
292 293  
293 294 while (1) {
294 295 if (k >= TFTP_FILENAME_MAX || k >= pktlen) {
... ... @@ -315,7 +316,8 @@ static void tftp_handle_rrq(Slirp *slirp, struct tftp_t *tp, int pktlen)
315 316 k += 6; /* skipping octet */
316 317  
317 318 /* do sanity checks on the filename */
318   - if (req_fname[0] != '/' || req_fname[strlen(req_fname) - 1] == '/' ||
  319 + if (!strncmp(req_fname, "../", 3) ||
  320 + req_fname[strlen(req_fname) - 1] == '/' ||
319 321 strstr(req_fname, "/../")) {
320 322 tftp_send_error(spt, 2, "Access violation", tp);
321 323 return;
... ...