From 6a36978e6931e6601be586eb313375335f2cfaa3 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Fri, 23 Aug 2013 11:17:53 -0400 Subject: [PATCH] rpc: comment on linux_cred encoding, treat all as unsigned The encoding of linux creds is a bit confusing. Also: I think in practice it doesn't really matter whether we treat any of these things as signed or unsigned, but unsigned seems more straightforward: uid_t/gid_t are unsigned and it simplifies the ngroups overflow check. Tested-by: Simo Sorce Signed-off-by: J. Bruce Fields --- net/sunrpc/auth_gss/gss_rpc_xdr.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c index f5067b2..3c19c7d 100644 --- a/net/sunrpc/auth_gss/gss_rpc_xdr.c +++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c @@ -166,14 +166,15 @@ static int dummy_dec_opt_array(struct xdr_stream *xdr, return 0; } -static int get_s32(struct xdr_stream *xdr, s32 *res) +static int get_host_u32(struct xdr_stream *xdr, u32 *res) { __be32 *p; p = xdr_inline_decode(xdr, 4); if (!p) return -EINVAL; - memcpy(res, p, sizeof(s32)); + /* Contents of linux creds are all host-endian: */ + memcpy(res, p, sizeof(u32)); return 0; } @@ -182,8 +183,9 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr, { u32 length; __be32 *p; - s32 tmp; - int N, i, err; + u32 tmp; + u32 N; + int i, err; p = xdr_inline_decode(xdr, 4); if (unlikely(p == NULL)) @@ -195,19 +197,19 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr, return -ENOSPC; /* uid */ - err = get_s32(xdr, &tmp); + err = get_host_u32(xdr, &tmp); if (err) return err; creds->cr_uid = make_kuid(&init_user_ns, tmp); /* gid */ - err = get_s32(xdr, &tmp); + err = get_host_u32(xdr, &tmp); if (err) return err; creds->cr_gid = make_kgid(&init_user_ns, tmp); /* number of additional gid's */ - err = get_s32(xdr, &tmp); + err = get_host_u32(xdr, &tmp); if (err) return err; N = tmp; @@ -220,7 +222,7 @@ static int gssx_dec_linux_creds(struct xdr_stream *xdr, /* gid's */ for (i = 0; i < N; i++) { kgid_t kgid; - err = get_s32(xdr, &tmp); + err = get_host_u32(xdr, &tmp); if (err) goto out_free_groups; err = -EINVAL; -- 2.7.4