Skip to content
  1. Mar 18, 2022
  2. Mar 17, 2022
  3. Mar 16, 2022
  4. Mar 15, 2022
  5. Mar 14, 2022
    • Brian Masney's avatar
      crypto: qcom-rng - ensure buffer for generate is completely filled · a680b183
      Brian Masney authored
      The generate function in struct rng_alg expects that the destination
      buffer is completely filled if the function returns 0. qcom_rng_read()
      can run into a situation where the buffer is partially filled with
      randomness and the remaining part of the buffer is zeroed since
      qcom_rng_generate() doesn't check the return value. This issue can
      be reproduced by running the following from libkcapi:
      
          kcapi-rng -b 9000000 > OUTFILE
      
      The generated OUTFILE will have three huge sections that contain all
      zeros, and this is caused by the code where the test
      'val & PRNG_STATUS_DATA_AVAIL' fails.
      
      Let's fix this issue by ensuring that qcom_rng_read() always returns
      with a full buffer if the function returns success. Let's also have
      qcom_rng_generate() return the correct value.
      
      Here's some statistics from the ent project
      (https://www.fourmilab.ch/random/
      
      ) that shows information about the
      quality of the generated numbers:
      
          $ ent -c qcom-random-before
          Value Char Occurrences Fraction
            0           606748   0.067416
            1            33104   0.003678
            2            33001   0.003667
          ...
          253   �        32883   0.003654
          254   �        33035   0.003671
          255   �        33239   0.003693
      
          Total:       9000000   1.000000
      
          Entropy = 7.811590 bits per byte.
      
          Optimum compression would reduce the size
          of this 9000000 byte file by 2 percent.
      
          Chi square distribution for 9000000 samples is 9329962.81, and
          randomly would exceed this value less than 0.01 percent of the
          times.
      
          Arithmetic mean value of data bytes is 119.3731 (127.5 = random).
          Monte Carlo value for Pi is 3.197293333 (error 1.77 percent).
          Serial correlation coefficient is 0.159130 (totally uncorrelated =
          0.0).
      
      Without this patch, the results of the chi-square test is 0.01%, and
      the numbers are certainly not random according to ent's project page.
      The results improve with this patch:
      
          $ ent -c qcom-random-after
          Value Char Occurrences Fraction
            0            35432   0.003937
            1            35127   0.003903
            2            35424   0.003936
          ...
          253   �        35201   0.003911
          254   �        34835   0.003871
          255   �        35368   0.003930
      
          Total:       9000000   1.000000
      
          Entropy = 7.999979 bits per byte.
      
          Optimum compression would reduce the size
          of this 9000000 byte file by 0 percent.
      
          Chi square distribution for 9000000 samples is 258.77, and randomly
          would exceed this value 42.24 percent of the times.
      
          Arithmetic mean value of data bytes is 127.5006 (127.5 = random).
          Monte Carlo value for Pi is 3.141277333 (error 0.01 percent).
          Serial correlation coefficient is 0.000468 (totally uncorrelated =
          0.0).
      
      This change was tested on a Nexus 5 phone (msm8974 SoC).
      
      Signed-off-by: default avatarBrian Masney <bmasney@redhat.com>
      Fixes: ceec5f5b
      
       ("crypto: qcom-rng - Add Qcom prng driver")
      Cc: stable@vger.kernel.org # 4.19+
      Reviewed-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
      Reviewed-by: default avatarAndrew Halaney <ahalaney@redhat.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      a680b183
    • Linus Torvalds's avatar
      Linux 5.17-rc8 · 09688c01
      Linus Torvalds authored
      v5.17-rc8
      09688c01
    • Linus Torvalds's avatar
      Merge tag 'x86_urgent_for_v5.17_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · f0e18b03
      Linus Torvalds authored
      Pull x86 fixes from Borislav Petkov:
      
       - Free shmem backing storage for SGX enclave pages when those are
         swapped back into EPC memory
      
       - Prevent do_int3() from being kprobed, to avoid recursion
      
       - Remap setup_data and setup_indirect structures properly when
         accessing their members
      
       - Correct the alternatives patching order for modules too
      
      * tag 'x86_urgent_for_v5.17_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/sgx: Free backing memory after faulting the enclave page
        x86/traps: Mark do_int3() NOKPROBE_SYMBOL
        x86/boot: Add setup_indirect support in early_memremap_is_setup_data()
        x86/boot: Fix memremap of setup_indirect structures
        x86/module: Fix the paravirt vs alternative order
      f0e18b03
  6. Mar 13, 2022
  7. Mar 12, 2022