Markus Armbruster <arm...@redhat.com> writes: > I'ld like to suggest a clearer subject: > > migration: Plug memory leak with migration URIs > > Het Gala <het.g...@nutanix.com> writes: > >> 'channel' in qmp_migrate() and qmp_migrate_incoming() is not >> auto-freed. migrate_uri_parse() allocates memory to 'channel' if > > Not sure we need the first sentence. QMP commands never free their > arguments. > >> the user opts for old syntax - uri, which is leaked because there >> is no code for freeing 'channel'. >> So, free channel to avoid memory leak in case where 'channels' >> is empty and uri parsing is required. >> Fixes: 5994024f ("migration: Implement MigrateChannelList to qmp >> migration flow") >> >> Signed-off-by: Het Gala <het.g...@nutanix.com> >> Suggested-by: Markus Armbruster <arm...@redhat.com> > > Keep the Fixes: tag on a single line, and next to the other tags: > > [...] > is empty and uri parsing is required. > > Fixes: 5994024f ("migration: Implement MigrateChannelList to qmp migration > flow") > Signed-off-by: Het Gala <het.g...@nutanix.com> > Suggested-by: Markus Armbruster <arm...@redhat.com> > >> --- >> migration/migration.c | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/migration/migration.c b/migration/migration.c >> index 28a34c9068..34340f3440 100644 >> --- a/migration/migration.c >> +++ b/migration/migration.c >> @@ -515,7 +515,7 @@ static void qemu_start_incoming_migration(const char >> *uri, bool has_channels, >> MigrationChannelList *channels, >> Error **errp) >> { >> - MigrationChannel *channel = NULL; >> + g_autoptr(MigrationChannel) channel = NULL; >> MigrationAddress *addr = NULL; >> MigrationIncomingState *mis = migration_incoming_get_current(); >> >> @@ -533,18 +533,18 @@ static void qemu_start_incoming_migration(const char >> *uri, bool has_channels, >> error_setg(errp, "Channel list has more than one entries"); >> return; >> } >> - channel = channels->value; >> + addr = channels->value->addr; >> } else if (uri) { >> /* caller uses the old URI syntax */ >> if (!migrate_uri_parse(uri, &channel, errp)) { >> return; >> } >> + addr = channel->addr; >> } else { >> error_setg(errp, "neither 'uri' or 'channels' argument are " >> "specified in 'migrate-incoming' qmp command "); >> return; >> } >> - addr = channel->addr; >> >> /* transport mechanism not suitable for migration? */ >> if (!migration_channels_and_transport_compatible(addr, errp)) { >> @@ -1932,7 +1932,7 @@ void qmp_migrate(const char *uri, bool has_channels, >> bool resume_requested; >> Error *local_err = NULL; >> MigrationState *s = migrate_get_current(); >> - MigrationChannel *channel = NULL; >> + g_autoptr(MigrationChannel) channel = NULL; >> MigrationAddress *addr = NULL; >> >> /* >> @@ -1949,18 +1949,18 @@ void qmp_migrate(const char *uri, bool has_channels, >> error_setg(errp, "Channel list has more than one entries"); >> return; >> } >> - channel = channels->value; >> + addr = channels->value->addr; >> } else if (uri) { >> /* caller uses the old URI syntax */ >> if (!migrate_uri_parse(uri, &channel, errp)) { >> return; >> } >> + addr = channel->addr; >> } else { >> error_setg(errp, "neither 'uri' or 'channels' argument are " >> "specified in 'migrate' qmp command "); >> return; >> } >> - addr = channel->addr; >> >> /* transport mechanism not suitable for migration? */ >> if (!migration_channels_and_transport_compatible(addr, errp)) { > > I tested this with an --enable-santizers build. Before the patch: > > $ qemu-system-x86_64 -nodefaults -S -display none -monitor stdio > -incoming unix:123 > ==3260873==WARNING: ASan doesn't fully support makecontext/swapcontext > functions and may produce false positives in some cases! > QEMU 8.1.92 monitor - type 'help' for more information > (qemu) q > > ================================================================= > ==3260873==ERROR: LeakSanitizer: detected memory leaks > > Direct leak of 40 byte(s) in 1 object(s) allocated from: > #0 0x7f0ba08ba097 in calloc (/lib64/libasan.so.8+0xba097) > #1 0x7f0b9f4eb5b0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x5f5b0) > #2 0x55b446454dbe in migrate_uri_parse ../migration/migration.c:490 > #3 0x55b4464557c9 in qemu_start_incoming_migration > ../migration/migration.c:539 > #4 0x55b446461687 in qmp_migrate_incoming > ../migration/migration.c:1734 > #5 0x55b4463df1c2 in qmp_x_exit_preconfig ../system/vl.c:2718 > #6 0x55b4463e4d8e in qemu_init ../system/vl.c:3753 > #7 0x55b446f63ca9 in main ../system/main.c:47 > #8 0x7f0b9d04a54f in __libc_start_call_main (/lib64/libc.so.6+0x2754f) > > Direct leak of 16 byte(s) in 1 object(s) allocated from: > #0 0x7f0ba08ba097 in calloc (/lib64/libasan.so.8+0xba097) > #1 0x7f0b9f4eb5b0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x5f5b0) > #2 0x55b4464557c9 in qemu_start_incoming_migration > ../migration/migration.c:539 > #3 0x55b446461687 in qmp_migrate_incoming > ../migration/migration.c:1734 > #4 0x55b4463df1c2 in qmp_x_exit_preconfig ../system/vl.c:2718 > #5 0x55b4463e4d8e in qemu_init ../system/vl.c:3753 > #6 0x55b446f63ca9 in main ../system/main.c:47 > #7 0x7f0b9d04a54f in __libc_start_call_main (/lib64/libc.so.6+0x2754f) > > Direct leak of 8 byte(s) in 1 object(s) allocated from: > #0 0x7f0ba08bb1a8 in operator new(unsigned long) > (/lib64/libasan.so.8+0xbb1a8) > #1 0x7f0b9a9255b7 in _sub_I_65535_0.0 > (/lib64/libtcmalloc_minimal.so.4+0xe5b7) > > Indirect leak of 48 byte(s) in 1 object(s) allocated from: > #0 0x7f0ba08ba097 in calloc (/lib64/libasan.so.8+0xba097) > #1 0x7f0b9f4eb5b0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x5f5b0) > #2 0x55b4464557c9 in qemu_start_incoming_migration > ../migration/migration.c:539 > #3 0x55b446461687 in qmp_migrate_incoming > ../migration/migration.c:1734 > #4 0x55b4463df1c2 in qmp_x_exit_preconfig ../system/vl.c:2718 > #5 0x55b4463e4d8e in qemu_init ../system/vl.c:3753 > #6 0x55b446f63ca9 in main ../system/main.c:47 > #7 0x7f0b9d04a54f in __libc_start_call_main (/lib64/libc.so.6+0x2754f) > > Indirect leak of 4 byte(s) in 1 object(s) allocated from: > #0 0x7f0ba08ba6af in __interceptor_malloc > (/lib64/libasan.so.8+0xba6af) > #1 0x7f0b9f4eb128 in g_malloc (/lib64/libglib-2.0.so.0+0x5f128) > > SUMMARY: AddressSanitizer: 116 byte(s) leaked in 5 allocation(s). > > > Afterwards: > > ==3260526==WARNING: ASan doesn't fully support makecontext/swapcontext > functions and may produce false positives in some cases! > QEMU 8.1.92 monitor - type 'help' for more information > (qemu) q > > ================================================================= > ==3260526==ERROR: LeakSanitizer: detected memory leaks > > Direct leak of 40 byte(s) in 1 object(s) allocated from: > #0 0x7f97e54ba097 in calloc (/lib64/libasan.so.8+0xba097) > #1 0x7f97e41c75b0 in g_malloc0 (/lib64/libglib-2.0.so.0+0x5f5b0) > #2 0x55ae31b02dbe in migrate_uri_parse ../migration/migration.c:490 > #3 0x55ae31b0382c in qemu_start_incoming_migration > ../migration/migration.c:539 > #4 0x55ae31b0f724 in qmp_migrate_incoming > ../migration/migration.c:1734 > #5 0x55ae31a8d1c2 in qmp_x_exit_preconfig ../system/vl.c:2718 > #6 0x55ae31a92d8e in qemu_init ../system/vl.c:3753 > #7 0x55ae32611de2 in main ../system/main.c:47 > #8 0x7f97e1c4a54f in __libc_start_call_main (/lib64/libc.so.6+0x2754f) > > Direct leak of 8 byte(s) in 1 object(s) allocated from: > #0 0x7f97e54bb1a8 in operator new(unsigned long) > (/lib64/libasan.so.8+0xbb1a8) > #1 0x7f97df6055b7 in _sub_I_65535_0.0 > (/lib64/libtcmalloc_minimal.so.4+0xe5b7) > > SUMMARY: AddressSanitizer: 48 byte(s) leaked in 2 allocation(s). > > This confirms the patch succeeds at plugging leaks the -incoming path. > It also shows there's one left in migrate_uri_parse(): > > bool migrate_uri_parse(const char *uri, MigrationChannel **channel, > Error **errp) > { > g_autoptr(MigrationChannel) val = g_new0(MigrationChannel, 1); > g_autoptr(MigrationAddress) addr = g_new0(MigrationAddress, 1); > SocketAddress *saddr = NULL; > > Useless initializer. > > InetSocketAddress *isock = &addr->u.rdma; > strList **tail = &addr->u.exec.args; > > if (strstart(uri, "exec:", NULL)) { > addr->transport = MIGRATION_ADDRESS_TYPE_EXEC; > #ifdef WIN32 > QAPI_LIST_APPEND(tail, g_strdup(exec_get_cmd_path())); > QAPI_LIST_APPEND(tail, g_strdup("/c")); > #else > QAPI_LIST_APPEND(tail, g_strdup("/bin/sh")); > QAPI_LIST_APPEND(tail, g_strdup("-c")); > #endif > QAPI_LIST_APPEND(tail, g_strdup(uri + strlen("exec:"))); > } else if (strstart(uri, "rdma:", NULL)) { > if (inet_parse(isock, uri + strlen("rdma:"), errp)) { > qapi_free_InetSocketAddress(isock); > return false; > } > addr->transport = MIGRATION_ADDRESS_TYPE_RDMA; > } else if (strstart(uri, "tcp:", NULL) || > strstart(uri, "unix:", NULL) || > strstart(uri, "vsock:", NULL) || > strstart(uri, "fd:", NULL)) { > > Aside: indentation is off. > > addr->transport = MIGRATION_ADDRESS_TYPE_SOCKET; > saddr = socket_parse(uri, errp); > > @saddr allocated. > > if (!saddr) { > return false; > } > addr->u.socket.type = saddr->type; > addr->u.socket.u = saddr->u; > > Members of @saddr copied into @addr. > > } else if (strstart(uri, "file:", NULL)) { > addr->transport = MIGRATION_ADDRESS_TYPE_FILE; > addr->u.file.filename = g_strdup(uri + strlen("file:")); > if (file_parse_offset(addr->u.file.filename, &addr->u.file.offset, > errp)) { > return false; > } > } else { > error_setg(errp, "unknown migration protocol: %s", uri); > return false; > } > > val->channel_type = MIGRATION_CHANNEL_TYPE_MAIN; > val->addr = g_steal_pointer(&addr); > *channel = g_steal_pointer(&val); > > @saddr leaked. > > return true; > } > > Obvious fix: g_free(saddr) right after copying its members. > > Another fix: make @saddr g_autofree, and keep the initializer. > > Separate patch. Would you like to take care of it?
That is already being worked by someone else: [PATCH v3] migration: free 'saddr' since be no longer used https://lore.kernel.org/r/20231120031428.908295-1-zhouzong...@kylinos.cn