1. 08 Apr, 2017 23 commits
  2. 31 Mar, 2017 15 commits
  3. 30 Mar, 2017 2 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.4.58 · 0a5766a6
      Greg Kroah-Hartman authored
      0a5766a6
    • Jiri Slaby's avatar
      crypto: algif_hash - avoid zero-sized array · f8a62dbc
      Jiri Slaby authored
      commit 62071194 upstream.
      
      With this reproducer:
        struct sockaddr_alg alg = {
                .salg_family = 0x26,
                .salg_type = "hash",
                .salg_feat = 0xf,
                .salg_mask = 0x5,
                .salg_name = "digest_null",
        };
        int sock, sock2;
      
        sock = socket(AF_ALG, SOCK_SEQPACKET, 0);
        bind(sock, (struct sockaddr *)&alg, sizeof(alg));
        sock2 = accept(sock, NULL, NULL);
        setsockopt(sock, SOL_ALG, ALG_SET_KEY, "\x9b\xca", 2);
        accept(sock2, NULL, NULL);
      
      ==== 8< ======== 8< ======== 8< ======== 8< ====
      
      one can immediatelly see an UBSAN warning:
      UBSAN: Undefined behaviour in crypto/algif_hash.c:187:7
      variable length array bound value 0 <= 0
      CPU: 0 PID: 15949 Comm: syz-executor Tainted: G            E      4.4.30-0-default #1
      ...
      Call Trace:
      ...
       [<ffffffff81d598fd>] ? __ubsan_handle_vla_bound_not_positive+0x13d/0x188
       [<ffffffff81d597c0>] ? __ubsan_handle_out_of_bounds+0x1bc/0x1bc
       [<ffffffffa0e2204d>] ? hash_accept+0x5bd/0x7d0 [algif_hash]
       [<ffffffffa0e2293f>] ? hash_accept_nokey+0x3f/0x51 [algif_hash]
       [<ffffffffa0e206b0>] ? hash_accept_parent_nokey+0x4a0/0x4a0 [algif_hash]
       [<ffffffff8235c42b>] ? SyS_accept+0x2b/0x40
      
      It is a correct warning, as hash state is propagated to accept as zero,
      but creating a zero-length variable array is not allowed in C.
      
      Fix this as proposed by Herbert -- do "?: 1" on that site. No sizeof or
      similar happens in the code there, so we just allocate one byte even
      though we do not use the array.
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Cc: "David S. Miller" <davem@davemloft.net> (maintainer:CRYPTO API)
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f8a62dbc