[Libguestfs] A few Coverity errors in nbdkit

[Richard W.M. Jones]

Hi Eric,

None of this is important, and may not even be bugs, but here are a
few issues raised with the latest run of Coverity on nbdkit 1.30.7.


**********************************************************************
*** filters/multi-conn

It seems as if "group_vector" is really leaked from this filter.  I
think it needs an unload handler to free it.


Error: GCC_ANALYZER_WARNING (CWE-401): [#def75]
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:195:14: warning[-Wanalyzer-malloc-leak]: leak of 'g'
nbdkit-1.30.7/common/utils/vector.h:44: included_from: Included from here.
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:46: included_from: Included from here.
nbdkit-1.30.7/common/utils/cleanup.h:56:3: note: in expansion of macro 'ACQUIRE_LOCK_FOR_CURRENT_SCOPE_1'
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:208:3: note: in expansion of macro 'ACQUIRE_LOCK_FOR_CURRENT_SCOPE'
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:46: included_from: Included from here.
nbdkit-1.30.7/common/utils/vector.h:132:12: note: in definition of macro 'DEFINE_VECTOR_TYPE'
nbdkit-1.30.7/common/utils/vector.h:132:12: note: in definition of macro 'DEFINE_VECTOR_TYPE'
nbdkit-1.30.7/common/utils/vector.h:116:3: note: in definition of macro 'DEFINE_VECTOR_TYPE'
nbdkit-1.30.7/common/utils/vector.h:44: included_from: Included from here.
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:46: included_from: Included from here.
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:87:1: note: in expansion of macro 'DEFINE_VECTOR_TYPE'
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:46: included_from: Included from here.
nbdkit-1.30.7/common/utils/vector.h:132:12: note: in definition of macro 'DEFINE_VECTOR_TYPE'
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:45: included_from: Included from here.
nbdkit-1.30.7/common/utils/cleanup.h:58:41: note: in definition of macro 'ACQUIRE_LOCK_FOR_CURRENT_SCOPE_1'
nbdkit-1.30.7/common/include/unique-name.h:40:37: note: in expansion of macro 'XXUNIQUE_NAME'
nbdkit-1.30.7/common/include/unique-name.h:41:34: note: in expansion of macro 'XUNIQUE_NAME'
nbdkit-1.30.7/common/utils/cleanup.h:56:45: note: in expansion of macro 'NBDKIT_UNIQUE_NAME'
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:208:3: note: in expansion of macro 'ACQUIRE_LOCK_FOR_CURRENT_SCOPE'
#  193|       r = next->can_multi_conn (next);
#  194|       if (r == -1)
#  195|->       return -1;
#  196|       if (r == 0)
#  197|         h->mode = EMULATE;

Error: CLANG_WARNING: [#def76]
nbdkit-1.30.7/filters/multi-conn/multi-conn.c:227:15: warning[unix.Malloc]: Potential leak of memory pointed to by 'g'
#  225|       }
#  226|       if (group_vector_append (&groups, g) == -1)
#  227|->       return -1;
#  228|       g->name = h->name;
#  229|       h->name = NULL;


**********************************************************************
*** server/protocol-handshake-newstyle.c

I think Coverity has a point here.  Certainly there is code before
this point which assigns conn->top_context = NULL, and it's not
immediately clear to me that the code that Coverity has highlighted is
unreachable in that case.


Error: CLANG_WARNING: [#def234]
nbdkit-1.30.7/server/protocol-handshake-newstyle.c:657:34: warning[core.NonNullParamChecker]: Null pointer passed to 1st parameter expecting 'nonnull'
#  655|             case NBD_INFO_DESCRIPTION:
#  656|               {
#  657|->               const char *desc = backend_export_description (conn->top_context);
#  658|   
#  659|                 if (!desc) {

Error: CLANG_WARNING: [#def235]
nbdkit-1.30.7/server/protocol-handshake-newstyle.c:676:19: warning[core.NonNullParamChecker]: Null pointer passed to 1st parameter expecting 'nonnull'
#  674|                 uint32_t minimum, preferred, maximum;
#  675|   
#  676|->               if (backend_block_size (conn->top_context,
#  677|                                         &minimum, &preferred, &maximum) == -1)
#  678|                   return -1;


**********************************************************************
*** server/public.c

Any clue about what this error means?


Error: ASSERT_SIDE_EFFECT (CWE-1006): [#def239]
nbdkit-1.30.7/server/public.c:728: assert_side_effect: Argument "quit" of assert() has a side effect because the variable is volatile.  The containing function might work differently in a non-debug build.
#  726|      * event, we know the connection should be shutting down.
#  727|      */
#  728|->   assert (quit ||
#  729|             (conn && conn->nworkers > 0 && connection_get_status () < 1) ||
#  730|             (conn && (fds[2].revents & (POLLRDHUP | POLLHUP | POLLERR |



Rich.

-- 
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