1. 21 Oct, 2011 1 commit
    • Nick Bowler's avatar
      crypto: ghash - Avoid null pointer dereference if no key is set · 7ed47b7d
      Nick Bowler authored
      The ghash_update function passes a pointer to gf128mul_4k_lle which will
      be NULL if ghash_setkey is not called or if the most recent call to
      ghash_setkey failed to allocate memory.  This causes an oops.  Fix this
      up by returning an error code in the null case.
      
      This is trivially triggered from unprivileged userspace through the
      AF_ALG interface by simply writing to the socket without setting a key.
      
      The ghash_final function has a similar issue, but triggering it requires
      a memory allocation failure in ghash_setkey _after_ at least one
      successful call to ghash_update.
      
        BUG: unable to handle kernel NULL pointer dereference at 00000670
        IP: [<d88c92d4>] gf128mul_4k_lle+0x23/0x60 [gf128mul]
        *pde = 00000000
        Oops: 0000 [#1] PREEMPT SMP
        Modules linked in: ghash_generic gf128mul algif_hash af_alg nfs lockd nfs_acl sunrpc bridge ipv6 stp llc
      
        Pid: 1502, comm: hashatron Tainted: G        W   3.1.0-rc9-00085-ge9308cfd #32 Bochs Bochs
        EIP: 0060:[<d88c92d4>] EFLAGS: 00000202 CPU: 0
        EIP is at gf128mul_4k_lle+0x23/0x60 [gf128mul]
        EAX: d69db1f0 EBX: d6b8ddac ECX: 00000004 EDX: 00000000
        ESI: 00000670 EDI: d6b8ddac EBP: d6b8ddc8 ESP: d6b8dda4
         DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
        Process hashatron (pid: 1502, ti=d6b8c000 task=d6810000 task.ti=d6b8c000)
        Stack:
         00000000 d69db1f0 00000163 00000000 d6b8ddc8 c101a520 d69db1f0 d52aa000
         00000ff0 d6b8dde8 d88d310f d6b8a3f8 d52aa000 00001000 d88d502c d6b8ddfc
         00001000 d6b8ddf4 c11676ed d69db1e8 d6b8de24 c11679ad d52aa000 00000000
        Call Trace:
         [<c101a520>] ? kmap_atomic_prot+0x37/0xa6
         [<d88d310f>] ghash_update+0x85/0xbe [ghash_generic]
         [<c11676ed>] crypto_shash_update+0x18/0x1b
         [<c11679ad>] shash_ahash_update+0x22/0x36
         [<c11679cc>] shash_async_update+0xb/0xd
         [<d88ce0ba>] hash_sendpage+0xba/0xf2 [algif_hash]
         [<c121b24c>] kernel_sendpage+0x39/0x4e
         [<d88ce000>] ? 0xd88cdfff
         [<c121b298>] sock_sendpage+0x37/0x3e
         [<c121b261>] ? kernel_sendpage+0x4e/0x4e
         [<c10b4dbc>] pipe_to_sendpage+0x56/0x61
         [<c10b4e1f>] splice_from_pipe_feed+0x58/0xcd
         [<c10b4d66>] ? splice_from_pipe_begin+0x10/0x10
         [<c10b51f5>] __splice_from_pipe+0x36/0x55
         [<c10b4d66>] ? splice_from_pipe_begin+0x10/0x10
         [<c10b6383>] splice_from_pipe+0x51/0x64
         [<c10b63c2>] ? default_file_splice_write+0x2c/0x2c
         [<c10b63d5>] generic_splice_sendpage+0x13/0x15
         [<c10b4d66>] ? splice_from_pipe_begin+0x10/0x10
         [<c10b527f>] do_splice_from+0x5d/0x67
         [<c10b6865>] sys_splice+0x2bf/0x363
         [<c129373b>] ? sysenter_exit+0xf/0x16
         [<c104dc1e>] ? trace_hardirqs_on_caller+0x10e/0x13f
         [<c129370c>] sysenter_do_call+0x12/0x32
        Code: 83 c4 0c 5b 5e 5f c9 c3 55 b9 04 00 00 00 89 e5 57 8d 7d e4 56 53 8d 5d e4 83 ec 18 89 45 e0 89 55 dc 0f b6 70 0f c1 e6 04 01 d6 <f3> a5 be 0f 00 00 00 4e 89 d8 e8 48 ff ff ff 8b 45 e0 89 da 0f
        EIP: [<d88c92d4>] gf128mul_4k_lle+0x23/0x60 [gf128mul] SS:ESP 0068:d6b8dda4
        CR2: 0000000000000670
        ---[ end trace 4eaa2a86a8e2da24 ]---
        note: hashatron[1502] exited with preempt_count 1
        BUG: scheduling while atomic: hashatron/1502/0x10000002
        INFO: lockdep is turned off.
        [...]
      Signed-off-by: default avatarNick Bowler <nbowler@elliptictech.com>
      Cc: stable@kernel.org [2.6.37+]
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      7ed47b7d
  2. 21 Sep, 2011 14 commits
  3. 20 Sep, 2011 25 commits