From d68b9c457e6298e941b8b574f921624c6c648218 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Wed, 21 Aug 2013 10:32:52 -0400 Subject: rpc: clean up decoding of gssproxy linux creds commit 778e512bb1d3315c6b55832248cd30c566c081d7 upstream. We can use the normal coding infrastructure here. Two minor behavior changes: - we're assuming no wasted space at the end of the linux cred. That seems to match gss-proxy's behavior, and I can't see why it would need to do differently in the future. - NGROUPS_MAX check added: note groups_alloc doesn't do this, this is the caller's responsibility. Tested-by: Simo Sorce Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/auth_gss/gss_rpc_xdr.c | 32 +++++++++++++------------------- 1 file changed, 13 insertions(+), 19 deletions(-) diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c index 3c85d1c8a028..f5067b2e0a08 100644 --- a/net/sunrpc/auth_gss/gss_rpc_xdr.c +++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c @@ -166,14 +166,14 @@ static int dummy_dec_opt_array(struct xdr_stream *xdr, return 0; } -static int get_s32(void **p, void *max, s32 *res) +static int get_s32(struct xdr_stream *xdr, s32 *res) { - void *base = *p; - void *next = (void *)((char *)base + sizeof(s32)); - if (unlikely(next > max || next < base)) + __be32 *p; + + p = xdr_inline_decode(xdr, 4); + if (!p) return -EINVAL; - memcpy(res, base, sizeof(s32)); - *p = next; + memcpy(res, p, sizeof(s32)); return 0; } @@ -182,7 +182,6 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr, { u32 length; __be32 *p; - void *q, *end; s32 tmp; int N, i, err; @@ -192,33 +191,28 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr, length = be32_to_cpup(p); - /* FIXME: we do not want to use the scratch buffer for this one - * may need to use functions that allows us to access an io vector - * directly */ - p = xdr_inline_decode(xdr, length); - if (unlikely(p == NULL)) + if (length > (3 + NGROUPS_MAX) * sizeof(u32)) return -ENOSPC; - q = p; - end = q + length; - /* uid */ - err = get_s32(&q, end, &tmp); + err = get_s32(xdr, &tmp); if (err) return err; creds->cr_uid = make_kuid(&init_user_ns, tmp); /* gid */ - err = get_s32(&q, end, &tmp); + err = get_s32(xdr, &tmp); if (err) return err; creds->cr_gid = make_kgid(&init_user_ns, tmp); /* number of additional gid's */ - err = get_s32(&q, end, &tmp); + err = get_s32(xdr, &tmp); if (err) return err; N = tmp; + if ((3 + N) * sizeof(u32) != length) + return -EINVAL; creds->cr_group_info = groups_alloc(N); if (creds->cr_group_info == NULL) return -ENOMEM; @@ -226,7 +220,7 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr, /* gid's */ for (i = 0; i < N; i++) { kgid_t kgid; - err = get_s32(&q, end, &tmp); + err = get_s32(xdr, &tmp); if (err) goto out_free_groups; err = -EINVAL; -- cgit v1.2.3