SUNRPC: fix copying of multiple pages in gss_read_proxy_verf() (d48c8124) · Commits · 戴 / test

When the passed token is longer than 4032 bytes, the remaining part of the token must be copied from the rqstp->rq_arg.pages. But the copy must make sure it happens in a consecutive way. With the existing code, the first memcpy copies 'length' bytes from argv->iobase, but since the header is in front, this never fills the whole first page of in_token->pages. The mecpy in the loop copies the following bytes, but starts writing at the next page of in_token->pages. This leaves the last bytes of page 0 unwritten. Symptoms were that users with many groups were not able to access NFS exports, when using Active Directory as the KDC. Signed-off-by:

Martijn de Gouw <martijn.de.gouw@prodrive-technologies.com> Fixes: "SUNRPC: Fix svcauth_gss_proxy_init()" Signed-off-by:

J. Bruce Fields <bfields@redhat.com>

net/sunrpc/auth_gss/svcauth_gss.c

+17 −10

Original line number	Diff line number	Diff line
		@@ -1147,9 +1147,9 @@ static int gss_read_proxy_verf(struct svc_rqst *rqstp,
		struct gssp_in_token *in_token)
		{
		struct kvec *argv = &rqstp->rq_arg.head[0];
		unsigned int page_base, length;
		int pages, i, res;
		size_t inlen;
		unsigned int length, pgto_offs, pgfrom_offs;
		int pages, i, res, pgto, pgfrom;
		size_t inlen, to_offs, from_offs;

		res = gss_read_common_verf(gc, argv, authp, in_handle);
		if (res)
		@@ -1177,17 +1177,24 @@ static int gss_read_proxy_verf(struct svc_rqst *rqstp,
		memcpy(page_address(in_token->pages[0]), argv->iov_base, length);
		inlen -= length;

		i = 1;
		page_base = rqstp->rq_arg.page_base;
		to_offs = length;
		from_offs = rqstp->rq_arg.page_base;
		while (inlen) {
		length = min_t(unsigned int, inlen, PAGE_SIZE);
		memcpy(page_address(in_token->pages[i]),
		page_address(rqstp->rq_arg.pages[i]) + page_base,
		pgto = to_offs >> PAGE_SHIFT;
		pgfrom = from_offs >> PAGE_SHIFT;
		pgto_offs = to_offs & ~PAGE_MASK;
		pgfrom_offs = from_offs & ~PAGE_MASK;

		length = min_t(unsigned int, inlen,
		min_t(unsigned int, PAGE_SIZE - pgto_offs,
		PAGE_SIZE - pgfrom_offs));
		memcpy(page_address(in_token->pages[pgto]) + pgto_offs,
		page_address(rqstp->rq_arg.pages[pgfrom]) + pgfrom_offs,
		length);

		to_offs += length;
		from_offs += length;
		inlen -= length;
		page_base = 0;
		i++;
		}
		return 0;
		}

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