fabrics: Fix uuid_from_dmi_entries() read buffer initialization

Valgrind complaining about accessing uninitialized memory:

==159962== Conditional jump or move depends on uninitialised value(s)
==159962==    at 0x484BCF6: rawmemchr (vg_replace_strmem.c:1564)
==159962==    by 0x4F52B15: _IO_str_init_static_internal (strops.c:41)
==159962==    by 0x4F1DAB1: UnknownInlinedFun (strfile.h:95)
==159962==    by 0x4F1DAB1: __isoc99_sscanf (isoc99_sscanf.c:28)
==159962==    by 0x7B77C97: uuid_from_dmi_entries (fabrics.c:969)
==159962==    by 0x7B84192: UnknownInlinedFun (fabrics.c:1059)
==159962==    by 0x7B84192: nvmf_hostnqn_generate (fabrics.c:1070)

diff --git a/src/nvme/fabrics.c b/src/nvme/fabrics.c
index f943090b28f18ee1ac1c6af3d0bebd8a0828106d..094a8afca0b33f38c11a1bddc4b171a7a7545221 100644 (file)
--- a/src/nvme/fabrics.c
+++ b/src/nvme/fabrics.c
@@ -946,7 +946,7 @@ static int uuid_from_dmi_entries(char *system_uuid)
        int f;
        DIR *d;
        struct dirent *de;
-       char buf[512];
+       char buf[512] = {0};
 
        system_uuid[0] = '\0';
        d = opendir(PATH_DMI_ENTRIES);
@@ -964,7 +964,7 @@ static int uuid_from_dmi_entries(char *system_uuid)
                        continue;
                len = read(f, buf, 512);
                close(f);
-               if (len < 0)
+               if (len <= 0)
                        continue;
                if (sscanf(buf, "%d", &type) != 1)
                        continue;
@@ -976,7 +976,7 @@ static int uuid_from_dmi_entries(char *system_uuid)
                        continue;
                len = read(f, buf, 512);
                close(f);
-               if (len < 0)
+               if (len <= 0)
                        continue;
                /* Sigh. https://en.wikipedia.org/wiki/Overengineering */
                /* DMTF SMBIOS 3.0 Section 7.2.1 System UUID */