1. 16 Jun, 2015 2 commits
    • Steve Cornelius's avatar
      crypto: caam - fix RNG buffer cache alignment · 412c98c1
      Steve Cornelius authored
      The hwrng output buffers (2) are cast inside of a a struct (caam_rng_ctx)
      allocated in one DMA-tagged region. While the kernel's heap allocator
      should place the overall struct on a cacheline aligned boundary, the 2
      buffers contained within may not necessarily align. Consenquently, the ends
      of unaligned buffers may not fully flush, and if so, stale data will be left
      behind, resulting in small repeating patterns.
      
      This fix aligns the buffers inside the struct.
      
      Note that not all of the data inside caam_rng_ctx necessarily needs to be
      DMA-tagged, only the buffers themselves require this. However, a fix would
      incur the expense of error-handling bloat in the case of allocation failure.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarSteve Cornelius <steve.cornelius@freescale.com>
      Signed-off-by: default avatarVictoria Milhoan <vicki.milhoan@freescale.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      412c98c1
    • Steve Cornelius's avatar
      crypto: caam - improve initalization for context state saves · 6fd4b156
      Steve Cornelius authored
      Multiple function in asynchronous hashing use a saved-state block,
      a.k.a. struct caam_hash_state, which holds a stash of information
      between requests (init/update/final). Certain values in this state
      block are loaded for processing using an inline-if, and when this
      is done, the potential for uninitialized data can pose conflicts.
      Therefore, this patch improves initialization of state data to
      prevent false assignments using uninitialized data in the state block.
      
      This patch addresses the following traceback, originating in
      ahash_final_ctx(), although a problem like this could certainly
      exhibit other symptoms:
      
      kernel BUG at arch/arm/mm/dma-mapping.c:465!
      Unable to handle kernel NULL pointer dereference at virtual address 00000000
      pgd = 80004000
      [00000000] *pgd=00000000
      Internal error: Oops: 805 [#1] PREEMPT SMP
      Modules linked in:
      CPU: 0    Not tainted  (3.0.15-01752-gdd441b9-dirty #40)
      PC is at __bug+0x1c/0x28
      LR is at __bug+0x18/0x28
      pc : [<80043240>]    lr : [<8004323c>]    psr: 60000013
      sp : e423fd98  ip : 60000013  fp : 0000001c
      r10: e4191b84  r9 : 00000020  r8 : 00000009
      r7 : 88005038  r6 : 00000001  r5 : 2d676572  r4 : e4191a60
      r3 : 00000000  r2 : 00000001  r1 : 60000093  r0 : 00000033
      Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
      Control: 10c53c7d  Table: 1000404a  DAC: 00000015
      Process cryptomgr_test (pid: 1306, stack limit = 0xe423e2f0)
      Stack: (0xe423fd98 to 0xe4240000)
      fd80:                                                       11807fd1 80048544
      fda0: 88005000 e4191a00 e5178040 8039dda0 00000000 00000014 2d676572 e4191008
      fdc0: 88005018 e4191a60 00100100 e4191a00 00000000 8039ce0c e423fea8 00000007
      fde0: e4191a00 e4227000 e5178000 8039ce18 e419183c 80203808 80a94a44 00000006
      fe00: 00000000 80207180 00000000 00000006 e423ff08 00000000 00000007 e5178000
      fe20: e41918a4 80a949b4 8c4844e2 00000000 00000049 74227000 8c4844e2 00000e90
      fe40: 0000000e 74227e90 ffff8c58 80ac29e0 e423fed4 8006a350 8c81625c e423ff5c
      fe60: 00008576 e4002500 00000003 00030010 e4002500 00000003 e5180000 e4002500
      fe80: e5178000 800e6d24 007fffff 00000000 00000010 e4001280 e4002500 60000013
      fea0: 000000d0 804df078 00000000 00000000 00000000 00000000 00000000 00000000
      fec0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
      fee0: 00000000 00000000 e4227000 e4226000 e4753000 e4752000 e40a5000 e40a4000
      ff00: e41e7000 e41e6000 00000000 00000000 00000000 e423ff14 e423ff14 00000000
      ff20: 00000400 804f9080 e5178000 e4db0b40 00000000 e4db0b80 0000047c 00000400
      ff40: 00000000 8020758c 00000400 ffffffff 0000008a 00000000 e4db0b40 80206e00
      ff60: e4049dbc 00000000 00000000 00000003 e423ffa4 80062978 e41a8bfc 00000000
      ff80: 00000000 e4049db4 00000013 e4049db0 00000013 00000000 00000000 00000000
      ffa0: e4db0b40 e4db0b40 80204cbc 00000013 00000000 00000000 00000000 80204cfc
      ffc0: e4049da0 80089544 80040a40 00000000 e4db0b40 00000000 00000000 00000000
      ffe0: e423ffe0 e423ffe0 e4049da0 800894c4 80040a40 80040a40 00000000 00000000
      [<80043240>] (__bug+0x1c/0x28) from [<80048544>] (___dma_single_dev_to_cpu+0x84)
      [<80048544>] (___dma_single_dev_to_cpu+0x84/0x94) from [<8039dda0>] (ahash_fina)
      [<8039dda0>] (ahash_final_ctx+0x180/0x428) from [<8039ce18>] (ahash_final+0xc/0)
      [<8039ce18>] (ahash_final+0xc/0x10) from [<80203808>] (crypto_ahash_op+0x28/0xc)
      [<80203808>] (crypto_ahash_op+0x28/0xc0) from [<80207180>] (test_hash+0x214/0x5)
      [<80207180>] (test_hash+0x214/0x5b8) from [<8020758c>] (alg_test_hash+0x68/0x8c)
      [<8020758c>] (alg_test_hash+0x68/0x8c) from [<80206e00>] (alg_test+0x7c/0x1b8)
      [<80206e00>] (alg_test+0x7c/0x1b8) from [<80204cfc>] (cryptomgr_test+0x40/0x48)
      [<80204cfc>] (cryptomgr_test+0x40/0x48) from [<80089544>] (kthread+0x80/0x88)
      [<80089544>] (kthread+0x80/0x88) from [<80040a40>] (kernel_thread_exit+0x0/0x8)
      Code: e59f0010 e1a01003 eb126a8d e3a03000 (e5833000)
      ---[ end trace d52a403a1d1eaa86 ]---
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarSteve Cornelius <steve.cornelius@freescale.com>
      Signed-off-by: default avatarVictoria Milhoan <vicki.milhoan@freescale.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      6fd4b156
  2. 26 May, 2015 1 commit
  3. 22 May, 2015 1 commit
  4. 18 May, 2015 1 commit
  5. 07 May, 2015 3 commits
  6. 04 May, 2015 2 commits
    • Álvaro Fernández Rojas's avatar
      hwrng: bcm63xx - Fix driver compilation · f440c4ee
      Álvaro Fernández Rojas authored
      - s/clk_didsable_unprepare/clk_disable_unprepare
      - s/prov/priv
      - s/error/ret (bcm63xx_rng_probe)
      
      Fixes: 6229c160 ("hwrng: bcm63xx - make use of devm_hwrng_register")
      Signed-off-by: default avatarÁlvaro Fernández Rojas <noltari@gmail.com>
      Acked-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      f440c4ee
    • Daniel Borkmann's avatar
      lib: make memzero_explicit more robust against dead store elimination · 7829fb09
      Daniel Borkmann authored
      In commit 0b053c95 ("lib: memzero_explicit: use barrier instead
      of OPTIMIZER_HIDE_VAR"), we made memzero_explicit() more robust in
      case LTO would decide to inline memzero_explicit() and eventually
      find out it could be elimiated as dead store.
      
      While using barrier() works well for the case of gcc, recent efforts
      from LLVMLinux people suggest to use llvm as an alternative to gcc,
      and there, Stephan found in a simple stand-alone user space example
      that llvm could nevertheless optimize and thus elimitate the memset().
      A similar issue has been observed in the referenced llvm bug report,
      which is regarded as not-a-bug.
      
      Based on some experiments, icc is a bit special on its own, while it
      doesn't seem to eliminate the memset(), it could do so with an own
      implementation, and then result in similar findings as with llvm.
      
      The fix in this patch now works for all three compilers (also tested
      with more aggressive optimization levels). Arguably, in the current
      kernel tree it's more of a theoretical issue, but imho, it's better
      to be pedantic about it.
      
      It's clearly visible with gcc/llvm though, with the below code: if we
      would have used barrier() only here, llvm would have omitted clearing,
      not so with barrier_data() variant:
      
        static inline void memzero_explicit(void *s, size_t count)
        {
          memset(s, 0, count);
          barrier_data(s);
        }
      
        int main(void)
        {
          char buff[20];
          memzero_explicit(buff, sizeof(buff));
          return 0;
        }
      
        $ gcc -O2 test.c
        $ gdb a.out
        (gdb) disassemble main
        Dump of assembler code for function main:
         0x0000000000400400  <+0>: lea   -0x28(%rsp),%rax
         0x0000000000400405  <+5>: movq  $0x0,-0x28(%rsp)
         0x000000000040040e <+14>: movq  $0x0,-0x20(%rsp)
         0x0000000000400417 <+23>: movl  $0x0,-0x18(%rsp)
         0x000000000040041f <+31>: xor   %eax,%eax
         0x0000000000400421 <+33>: retq
        End of assembler dump.
      
        $ clang -O2 test.c
        $ gdb a.out
        (gdb) disassemble main
        Dump of assembler code for function main:
         0x00000000004004f0  <+0>: xorps  %xmm0,%xmm0
         0x00000000004004f3  <+3>: movaps %xmm0,-0x18(%rsp)
         0x00000000004004f8  <+8>: movl   $0x0,-0x8(%rsp)
         0x0000000000400500 <+16>: lea    -0x18(%rsp),%rax
         0x0000000000400505 <+21>: xor    %eax,%eax
         0x0000000000400507 <+23>: retq
        End of assembler dump.
      
      As gcc, clang, but also icc defines __GNUC__, it's sufficient to define
      this in compiler-gcc.h only to be picked up. For a fallback or otherwise
      unsupported compiler, we define it as a barrier. Similarly, for ecc which
      does not support gcc inline asm.
      
      Reference: https://llvm.org/bugs/show_bug.cgi?id=15495Reported-by: default avatarStephan Mueller <smueller@chronox.de>
      Tested-by: default avatarStephan Mueller <smueller@chronox.de>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Stephan Mueller <smueller@chronox.de>
      Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
      Cc: mancha security <mancha1@zoho.com>
      Cc: Mark Charlebois <charlebm@gmail.com>
      Cc: Behan Webster <behanw@converseincode.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      7829fb09
  7. 24 Apr, 2015 2 commits
  8. 16 Apr, 2015 1 commit
  9. 15 Apr, 2015 27 commits