When building and populating domain NS a couple of functions are called that append paths to a string list. This string list is then inspected, one item at the time by qemuNamespacePrepareOneItem() which gathers all the info for given path (stat buffer, possible link target, ACLs, SELinux label) using qemuNamespaceMknodItemInit(). If the path needs to be created in the domain's private /dev then it's added onto this qemuNamespaceMknodData list which is freed later in the process. But, if the path does not need to be created in the domain's private /dev, then the memory allocated by qemuNamespaceMknodItemInit() is not freed anywhere leading to a leak.
Signed-off-by: Michal Privoznik <mpriv...@redhat.com> --- v2 of: https://www.redhat.com/archives/libvir-list/2020-September/msg00248.html diff to v2: - autocleanup approach is implemented in qemuNamespacePrepareOneItem() src/qemu/qemu_namespace.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/src/qemu/qemu_namespace.c b/src/qemu/qemu_namespace.c index 87f4fd8d58..b0d1d0d083 100644 --- a/src/qemu/qemu_namespace.c +++ b/src/qemu/qemu_namespace.c @@ -871,7 +871,7 @@ qemuDomainNamespaceAvailable(qemuDomainNamespace ns G_GNUC_UNUSED) typedef struct _qemuNamespaceMknodItem qemuNamespaceMknodItem; typedef qemuNamespaceMknodItem *qemuNamespaceMknodItemPtr; struct _qemuNamespaceMknodItem { - const char *file; + char *file; char *target; bool bindmounted; GStatBuf sb; @@ -892,6 +892,7 @@ struct _qemuNamespaceMknodData { static void qemuNamespaceMknodItemClear(qemuNamespaceMknodItemPtr item) { + VIR_FREE(item->file); VIR_FREE(item->target); virFileFreeACLs(&item->acl); #ifdef WITH_SELINUX @@ -900,6 +901,8 @@ qemuNamespaceMknodItemClear(qemuNamespaceMknodItemPtr item) } +G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(qemuNamespaceMknodItem, qemuNamespaceMknodItemClear); + static void qemuNamespaceMknodDataClear(qemuNamespaceMknodDataPtr data) { @@ -1091,7 +1094,7 @@ qemuNamespaceMknodItemInit(qemuNamespaceMknodItemPtr item, bool isLink; bool needsBindMount; - item->file = file; + item->file = g_strdup(file); if (g_lstat(file, &item->sb) < 0) { if (errno == ENOENT) @@ -1166,11 +1169,13 @@ qemuNamespacePrepareOneItem(qemuNamespaceMknodDataPtr data, size_t ndevMountsPath) { long ttl = sysconf(_SC_SYMLOOP_MAX); - const char *next = file; + g_autofree char *next = g_strdup(file); size_t i; while (1) { - qemuNamespaceMknodItem item = { 0 }; + g_auto(qemuNamespaceMknodItem) item = { 0 }; + bool isLink; + bool addToData = false; int rc; rc = qemuNamespaceMknodItemInit(&item, cfg, vm, next); @@ -1182,6 +1187,8 @@ qemuNamespacePrepareOneItem(qemuNamespaceMknodDataPtr data, return -1; } + isLink = S_ISLNK(item.sb.st_mode); + if (STRPREFIX(next, QEMU_DEVPREFIX)) { for (i = 0; i < ndevMountsPath; i++) { if (STREQ(devMountsPath[i], "/dev")) @@ -1190,12 +1197,18 @@ qemuNamespacePrepareOneItem(qemuNamespaceMknodDataPtr data, break; } - if (i == ndevMountsPath && - VIR_APPEND_ELEMENT_COPY(data->items, data->nitems, item) < 0) - return -1; + if (i == ndevMountsPath) + addToData = true; } - if (!S_ISLNK(item.sb.st_mode)) + g_free(next); + next = g_strdup(item.target); + + if (addToData && + VIR_APPEND_ELEMENT(data->items, data->nitems, item) < 0) + return -1; + + if (!isLink) break; if (ttl-- == 0) { @@ -1204,8 +1217,6 @@ qemuNamespacePrepareOneItem(qemuNamespaceMknodDataPtr data, next); return -1; } - - next = item.target; } return 0; -- 2.26.2
