• Arnaldo Carvalho de Melo's avatar
    perf evsel: Do not access outside hw cache name arrays · c53412ee
    Arnaldo Carvalho de Melo authored
    We have to check if the values are >= *_MAX, not just >, fix it.
    
    From the bugzilla report:
    
    ''In file /tools/perf/util/evsel.c  function __perf_evsel__hw_cache_name
    it appears that there is a bug that reads beyond the end of the buffer.
    The statement "if (type > PERF_COUNT_HW_CACHE_MAX)" allows type to be
    equal to the maximum value. Later, when statement "if
    (!perf_evsel__is_cache_op_valid(type, op))" is executed, the function
    can access array perf_evsel__hw_cache_stat[type] beyond the end of the
    buffer.
    
    It appears to me that the statement "if (type > PERF_COUNT_HW_CACHE_MAX)"
    should be "if (type >= PERF_COUNT_HW_CACHE_MAX)"
    
    Bug found with Coverity and manual code review. No attempts were made to
    execute the code with a maximum type value.''
    
    Committer note:
    
    Testing it:
    
      $ perf record -e $(echo $(perf list cache | cut -d \[ -f1) | sed 's/ /,/g') usleep 1
      [ perf record: Woken up 16 times to write data ]
      [ perf record: Captured and wrote 0.023 MB perf.data (34 samples) ]
      $ perf evlist
      L1-dcache-load-misses
      L1-dcache-loads
      L1-dcache-stores
      L1-icache-load-misses
      LLC-load-misses
      LLC-loads
      LLC-store-misses
      LLC-stores
      branch-load-misses
      branch-loads
      dTLB-load-misses
      dTLB-loads
      dTLB-store-misses
      dTLB-stores
      iTLB-load-misses
      iTLB-loads
      node-load-misses
      node-loads
      node-store-misses
      node-stores
      $ perf list cache
    
      List of pre-defined events (to be used in -e):
    
        L1-dcache-load-misses        [Hardware cache event]
        L1-dcache-loads              [Hardware cache event]
        L1-dcache-stores             [Hardware cache event]
        L1-icache-load-misses        [Hardware cache event]
        LLC-load-misses              [Hardware cache event]
        LLC-loads                    [Hardware cache event]
        LLC-store-misses             [Hardware cache event]
        LLC-stores                   [Hardware cache event]
        branch-load-misses           [Hardware cache event]
        branch-loads                 [Hardware cache event]
        dTLB-load-misses             [Hardware cache event]
        dTLB-loads                   [Hardware cache event]
        dTLB-store-misses            [Hardware cache event]
        dTLB-stores                  [Hardware cache event]
        iTLB-load-misses             [Hardware cache event]
        iTLB-loads                   [Hardware cache event]
        node-load-misses             [Hardware cache event]
        node-loads                   [Hardware cache event]
        node-store-misses            [Hardware cache event]
        node-stores                  [Hardware cache event]
      $
    Reported-by: default avatarBrian Sweeney <bsweeney@lgsinnovations.com>
    Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=153351Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    c53412ee
evsel.c 60.9 KB