linux.c: fix a pile of sscanf(NULL, ...) possibilities.

Covscan apparently can't figure out that rc!=error == buf!=NULL.

None of these should ever actually happen, because we're checking for
the error cases from the functions that should fill them in, but hey,
belt and suspenders.

Signed-off-by: Peter Jones <pjones@redhat.com>

diff --git a/src/linux.c b/src/linux.c
index 85b4ee3..f419ad4 100644 (file)
--- a/src/linux.c
+++ b/src/linux.c
@@ -297,7 +297,7 @@ sysfs_sata_get_port_info(uint32_t print_id, struct disk_info *info)
 
        rc = read_sysfs_file(&buf, "/sys/class/ata_port/ata%d/port_no",
                             print_id);
-       if (rc <= 0)
+       if (rc <= 0 || buf == NULL)
                return -1;
 
        rc = sscanf((char *)buf, "%d", &info->sata_info.ata_port);
@@ -361,12 +361,12 @@ sysfs_parse_nvme(uint8_t *buf, ssize_t size, ssize_t *off,
        rc = read_sysfs_file(&filebuf,
                             "/sys/class/block/nvme%dn%d/eui",
                             ctrl_id, ns_id);
-       if (rc < 0 && errno == ENOENT) {
+       if ((rc < 0 && errno == ENOENT) || filebuf == NULL) {
                rc = read_sysfs_file(&filebuf,
                             "/sys/class/block/nvme%dn%d/device/eui",
                             ctrl_id, ns_id);
        }
-       if (rc >= 0) {
+       if (rc >= 0 && filebuf != NULL) {
                uint8_t eui[8];
                if (rc < 23) {
                        errno = EINVAL;
@@ -606,7 +606,7 @@ sysfs_parse_sas(uint8_t *buf, ssize_t size, ssize_t *off,
        rc = read_sysfs_file(&filebuf,
                             "/sys/class/block/%s/device/sas_address",
                             disk_name);
-       if (rc < 0)
+       if (rc < 0 || filebuf == NULL)
                return -1;
 
        rc = sscanf((char *)filebuf, "%"PRIx64, &sas_address);
@@ -656,7 +656,7 @@ make_pci_path(uint8_t *buf, ssize_t size, char *pathstr, ssize_t *pathoff)
        rc = read_sysfs_file(&fbuf,
                             "/sys/devices/pci%04x:%02x/firmware_node/hid",
                             root_domain, root_bus);
-       if (rc < 0)
+       if (rc < 0 || fbuf == NULL)
                return -1;
 
        uint16_t tmp16 = 0;
@@ -679,7 +679,7 @@ make_pci_path(uint8_t *buf, ssize_t size, char *pathstr, ssize_t *pathoff)
        rc = read_sysfs_file(&fbuf,
                             "/sys/devices/pci%4x:%02x/firmware_node/uid",
                             root_domain, root_bus);
-       if (rc <= 0 && errno != ENOENT)
+       if ((rc <= 0 && errno != ENOENT) || fbuf == NULL)
                return -1;
        if (rc > 0) {
                rc = sscanf((char *)fbuf, "%"PRIu64"\n", &acpi_uid_int);