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  1. RHEL
  2. RHEL-82799

valgrind: ld.so memcmp interceptor required on x86_64

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    • Icon: Bug Bug
    • Resolution: Unresolved
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    • rhel-10.1
    • CentOS Stream 10, rhel-10.0
    • valgrind
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    • valgrind-3.24.0-6.el10
    • Yes
    • Low
    • ZStream, Patch
    • 1
    • rhel-pt-perf-tools
    • ssg_platform_tools
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    • PT PerfDebug 2025 S04
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    • Unspecified
    • Unspecified
    • Unspecified
    • x86_64
    • None

      Running the upstream PCP regression suite we have recently started observing warnings from valgrind relating to use of dlopen in one of the PCP tools.  AFAICT this is not a PCP issue, but happy to be corrected.  The following is the back trace and valgrind suppressions file we are using (hopefully only temporarily):

       

      # from qa/1467 on vm14 (CentOS Stream10)
      # Invalid read of size 32
      # at 0x40242D9: bcmp (memcmp-avx2-movbe.S:415)
      # by 0x40069BD: fillin_rpath.isra.0 (dl-load.c:510)
      # by 0x4006C6A: decompose_rpath (dl-load.c:654)
      # by 0x4009375: _dl_map_object (dl-load.c:2040)
      # by 0x4002934: openaux (dl-deps.c:64)
      # by 0x40014E0: _dl_catch_exception (dl-catch.c:237)
      # by 0x4002D97: _dl_map_object_deps (dl-deps.c:232)
      # by 0x400CB70: dl_open_worker_begin (dl-open.c:613)
      # by 0x40014E0: _dl_catch_exception (dl-catch.c:237)
      # by 0x400C256: dl_open_worker (dl-open.c:778)
      # by 0x40014E0: _dl_catch_exception (dl-catch.c:237)
      # by 0x400C6B0: _dl_open (dl-open.c:880)
      # ...
      {
         _dl_open botch
         Memcheck:Addr32
         fun:bcmp
         ...
         fun:decompose_rpath
         fun:_dl_map_object
         fun:openaux
         fun:_dl_catch_exception
         ...
         fun:_dl_open
      } 

      The test in question is using the dbpmda(1) debugging utility, and loads the PCP "simple" PMDA (I can give more details if needed here, but hopefully someone recognizes recent glibc changes relating to this stack...?)

      We do not see this issue on any other platform and this test has existed for a number of years in the PCP testsuite, working fine over many versions of glibc and valgrind.

      I marked this ticket as 'important' as there may be security implications for server processes calling dlopen here - feel free to adjust up/down though of course, this is just an initial guess at severity level.

       

              rhn-engineering-mjw Mark Wielaard
              nathans@redhat.com Nathan Scott
              Mark Wielaard Mark Wielaard
              Martin Cermak Martin Cermak
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                Created:
                Updated: