[dpdk-dev] [PATCH] eal: fix leak in shared lib mode detection

[David Marchand]

This is reported by our internal covscan:

1. dpdk-20.11/lib/librte_eal/common/eal_common_options.c:508: alloc_fn:
Storage is returned from allocation function "dlopen".
6. dpdk-20.11/lib/librte_eal/common/eal_common_options.c:508:
leaked_storage: Failing to save or free storage allocated by
"dlopen("librte_eal.so.21.0", 5)" leaks it.

 #   506|        * shared library is not already loaded i.e. it's
 #   statically linked.)
 #   507|        */
 #   508|->     if (dlopen("librte_eal.so."ABI_VERSION, RTLD_LAZY |
 #   RTLD_NOLOAD) != NULL &&
 #   509|                       *default_solib_dir != '\0' &&
 #   510|                       stat(default_solib_dir, &sb) == 0 &&

This leak is not an issue per se, but on the other hand, this is easy
to fix and I prefer not having to waive this warning later.

Fixes: 06c7871dde01 ("eal: restrict default plugin path to shared lib mode")
Cc: sta...@dpdk.org

Signed-off-by: David Marchand <david.march...@redhat.com>
---
 lib/eal/common/eal_common_options.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/eal/common/eal_common_options.c 
b/lib/eal/common/eal_common_options.c
index 97ab6e00fd..ff5861b5f3 100644
--- a/lib/eal/common/eal_common_options.c
+++ b/lib/eal/common/eal_common_options.c
@@ -509,10 +509,14 @@ is_shared_build(void)
        }
 
        while (len >= minlen) {
+               void *handle;
+
                /* check if we have this .so loaded, if so - shared build */
                RTE_LOG(DEBUG, EAL, "Checking presence of .so '%s'\n", soname);
-               if (dlopen(soname, RTLD_LAZY | RTLD_NOLOAD) != NULL) {
+               handle = dlopen(soname, RTLD_LAZY | RTLD_NOLOAD);
+               if (handle != NULL) {
                        RTE_LOG(INFO, EAL, "Detected shared linkage of DPDK\n");
+                       dlclose(handle);
                        return 1;
                }
 
-- 
2.23.0