Merge branch 'for-3.16' of git://linux-nfs.org/~bfields/linux

Pull nfsd bugfixes from Bruce Fields:
 "By coincidence, two NFSv4 symlink bugs, one introduced in the 3.16 xdr
  encoding rewrite, the other a decoding bug that I think we've had
  since the start but that just doesn't trigger very often"

* 'for-3.16' of git://linux-nfs.org/~bfields/linux:
  nfs: fix nfs4d readlink truncated packet
  nfsd: fix rare symlink decoding bug
This commit is contained in:
Linus Torvalds 2014-07-03 18:33:22 -07:00
commit 0fba687f9b
2 changed files with 13 additions and 11 deletions

View File

@ -617,15 +617,6 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
switch (create->cr_type) {
case NF4LNK:
/* ugh! we have to null-terminate the linktext, or
* vfs_symlink() will choke. it is always safe to
* null-terminate by brute force, since at worst we
* will overwrite the first byte of the create namelen
* in the XDR buffer, which has already been extracted
* during XDR decode.
*/
create->cr_linkname[create->cr_linklen] = 0;
status = nfsd_symlink(rqstp, &cstate->current_fh,
create->cr_name, create->cr_namelen,
create->cr_linkname, create->cr_linklen,

View File

@ -600,7 +600,18 @@ nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create
READ_BUF(4);
create->cr_linklen = be32_to_cpup(p++);
READ_BUF(create->cr_linklen);
SAVEMEM(create->cr_linkname, create->cr_linklen);
/*
* The VFS will want a null-terminated string, and
* null-terminating in place isn't safe since this might
* end on a page boundary:
*/
create->cr_linkname =
kmalloc(create->cr_linklen + 1, GFP_KERNEL);
if (!create->cr_linkname)
return nfserr_jukebox;
memcpy(create->cr_linkname, p, create->cr_linklen);
create->cr_linkname[create->cr_linklen] = '\0';
defer_free(argp, kfree, create->cr_linkname);
break;
case NF4BLK:
case NF4CHR:
@ -3267,7 +3278,7 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd
wire_count = htonl(maxcount);
write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
xdr_truncate_encode(xdr, length_offset + 4 + maxcount);
xdr_truncate_encode(xdr, length_offset + 4 + ALIGN(maxcount, 4));
if (maxcount & 3)
write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
&zero, 4 - (maxcount&3));