3:49 a.m.
I was notified about a virmacmaptest crash that happens on FreeBSD.
Interestingly, the problem occurs on Linux too, but for some reason
the process is not getting SIGSEGV.
Michal Privoznik (2):
virmacmap: Fix variable handling
virmacmap: Don't use hash table dataFree callback
src/util/virmacmap.c | 32 ++++++++++++++++++--------------
1 file changed, 18 insertions(+), 14 deletions(-)
--
2.11.0
3:49 a.m.
New subject: [libvirt] [PATCH 1/2] virmacmap: Fix variable handling
In virMacMapRemoveLocked() we have two variables: @macsList and
@newMacsList. Obviously, @newMacsList is supposed to hold pointer
to modified list but in fact it holds pointer to the old list.
It's confusing.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/util/virmacmap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/util/virmacmap.c b/src/util/virmacmap.c
index 36c364e10..11b3e0334 100644
--- a/src/util/virmacmap.c
+++ b/src/util/virmacmap.c
@@ -121,8 +121,8 @@ virMacMapRemoveLocked(virMacMapPtr mgr,
return 0;
newMacsList = macsList;
- virStringListRemove(&macsList, mac);
- if (!macsList) {
+ virStringListRemove(&newMacsList, mac);
+ if (!newMacsList) {
virHashSteal(mgr->macs, domain);
} else {
if (macsList != newMacsList &&
--
2.11.0
3:49 a.m.
New subject: [libvirt] [PATCH 2/2] virmacmap: Don't use hash table dataFree callback
Due to nature of operations we do over the string list (more
precisely due to how virStringListRemove() works), it is not the
best idea to use dataFree callback. Problem is, on MAC address
remove, the string list remove function modifies the original
list in place. Then, virHashUpdateEntry() is called which frees
all the data stored in the list rendering @newMacsList point to
freed data.
==16002== Invalid read of size 8
==16002== at 0x50BC083: virFree (viralloc.c:582)
==16002== by 0x513DC39: virStringListFree (virstring.c:251)
==16002== by 0x51089B4: virMacMapHashFree (virmacmap.c:67)
==16002== by 0x50EF30B: virHashAddOrUpdateEntry (virhash.c:352)
==16002== by 0x50EF4FD: virHashUpdateEntry (virhash.c:415)
==16002== by 0x5108BED: virMacMapRemoveLocked (virmacmap.c:129)
==16002== by 0x51092D5: virMacMapRemove (virmacmap.c:346)
==16002== by 0x402F02: testMACRemove (virmacmaptest.c:107)
==16002== by 0x403F15: virTestRun (testutils.c:180)
==16002== by 0x4032C4: mymain (virmacmaptest.c:205)
==16002== by 0x405A3B: virTestMain (testutils.c:992)
==16002== by 0x403D87: main (virmacmaptest.c:237)
==16002== Address 0xdd5a4d0 is 0 bytes inside a block of size 24 free'd
==16002== at 0x4C2AD6F: realloc (vg_replace_malloc.c:693)
==16002== by 0x50BB99B: virReallocN (viralloc.c:245)
==16002== by 0x513DC0B: virStringListRemove (virstring.c:235)
==16002== by 0x5108BA6: virMacMapRemoveLocked (virmacmap.c:124)
==16002== by 0x51092D5: virMacMapRemove (virmacmap.c:346)
==16002== by 0x402F02: testMACRemove (virmacmaptest.c:107)
==16002== by 0x403F15: virTestRun (testutils.c:180)
==16002== by 0x4032C4: mymain (virmacmaptest.c:205)
==16002== by 0x405A3B: virTestMain (testutils.c:992)
==16002== by 0x403D87: main (virmacmaptest.c:237)
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/util/virmacmap.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/src/util/virmacmap.c b/src/util/virmacmap.c
index 11b3e0334..a9697e3d9 100644
--- a/src/util/virmacmap.c
+++ b/src/util/virmacmap.c
@@ -53,21 +53,25 @@ struct virMacMap {
static virClassPtr virMacMapClass;
+static int
+virMacMapHashFree(void *payload,
+ const void *name ATTRIBUTE_UNUSED,
+ void *opaque ATTRIBUTE_UNUSED)
+{
+ virStringListFree(payload);
+ return 0;
+}
+
+
static void
virMacMapDispose(void *obj)
{
virMacMapPtr mgr = obj;
+ virHashForEach(mgr->macs, virMacMapHashFree, NULL);
virHashFree(mgr->macs);
}
-static void
-virMacMapHashFree(void *payload, const void *name ATTRIBUTE_UNUSED)
-{
- virStringListFree(payload);
-}
-
-
static int virMacMapOnceInit(void)
{
if (!(virMacMapClass = virClassNew(virClassForObjectLockable(),
@@ -88,19 +92,20 @@ virMacMapAddLocked(virMacMapPtr mgr,
const char *mac)
{
int ret = -1;
- const char **macsList = NULL;
+ char **macsList = NULL;
char **newMacsList = NULL;
if ((macsList = virHashLookup(mgr->macs, domain)) &&
- virStringListHasString(macsList, mac)) {
+ virStringListHasString((const char**) macsList, mac)) {
ret = 0;
goto cleanup;
}
- if (!(newMacsList = virStringListAdd(macsList, mac)) ||
+ if (!(newMacsList = virStringListAdd((const char **) macsList, mac)) ||
virHashUpdateEntry(mgr->macs, domain, newMacsList) < 0)
goto cleanup;
newMacsList = NULL;
+ virStringListFree(macsList);
ret = 0;
cleanup:
@@ -303,8 +308,7 @@ virMacMapNew(const char *file)
return NULL;
virObjectLock(mgr);
- if (!(mgr->macs = virHashCreate(VIR_MAC_HASH_TABLE_SIZE,
- virMacMapHashFree)))
+ if (!(mgr->macs = virHashCreate(VIR_MAC_HASH_TABLE_SIZE, NULL)))
goto error;
if (file &&
--
2.11.0
4:58 a.m.
Michal Privoznik wrote:
I was notified about a virmacmaptest crash that happens on FreeBSD.
Interestingly, the problem occurs on Linux too, but for some reason
the process is not getting SIGSEGV.
Michal Privoznik (2):
virmacmap: Fix variable handling
virmacmap: Don't use hash table dataFree callback
src/util/virmacmap.c | 32 ++++++++++++++++++--------------
1 file changed, 18 insertions(+), 14 deletions(-)
ACK
This looks reasonable and fixes the crash for me.
Roman Bogorodskiy
2913
days inactive
2913
days old
3 comments
2 participants
participants (2)
-
Michal Privoznik -
Roman Bogorodskiy