If a freeze notification is cleared with BC_CLEAR_FREEZE_NOTIFICATION
before calling binder_freeze_notification_done(), then it is detached
from its reference (e.g. ref->freeze) but the work remains queued in
proc->delivered_freeze. This leads to a memory leak when the process
exits as any pending entries in proc->delivered_freeze are not freed:
unreferenced object 0xffff38e8cfa36180 (size 64):
comm "binder-util", pid 655, jiffies 4294936641
hex dump (first 32 bytes):
b8 e9 9e c8 e8 38 ff ff b8 e9 9e c8 e8 38 ff ff .....8.......8..
0b 00 00 00 00 00 00 00 3c 1f 4b 00 00 00 00 00 ........<.K.....
backtrace (crc 95983b32):
[<000000000d0582cf>] kmemleak_alloc+0x34/0x40
[<000000009c99a513>] __kmalloc_cache_noprof+0x208/0x280
[<00000000313b1704>] binder_thread_write+0xdec/0x439c
[<000000000cbd33bb>] binder_ioctl+0x1b68/0x22cc
[<000000002bbedeeb>] __arm64_sys_ioctl+0x124/0x190
[<00000000b439adee>] invoke_syscall+0x6c/0x254
[<00000000173558fc>] el0_svc_common.constprop.0+0xac/0x230
[<0000000084f72311>] do_el0_svc+0x40/0x58
[<000000008b872457>] el0_svc+0x38/0x78
[<00000000ee778653>] el0t_64_sync_handler+0x120/0x12c
[<00000000a8ec61bf>] el0t_64_sync+0x190/0x194
This patch fixes the leak by ensuring that any pending entries in
proc->delivered_freeze are freed during binder_deferred_release().
Fixes: d579b04a52a1 ("binder: frozen notification")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Carlos Llamas <cmllamas@xxxxxxxxxx>
---
drivers/android/binder.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 415fc9759249..7c09b5e38e32 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -5155,6 +5155,16 @@ static void binder_release_work(struct binder_proc *proc,
} break;
case BINDER_WORK_NODE:
break;
+ case BINDER_WORK_CLEAR_FREEZE_NOTIFICATION: {
+ struct binder_ref_freeze *freeze;
+
+ freeze = container_of(w, struct binder_ref_freeze, work);
+ binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
+ "undelivered freeze notification, %016llx\n",
+ (u64)freeze->cookie);
+ kfree(freeze);
+ binder_stats_deleted(BINDER_STAT_FREEZE);
+ } break;
default:
pr_err("unexpected work type, %d, not freed\n",
wtype);
@@ -6273,6 +6283,7 @@ static void binder_deferred_release(struct binder_proc *proc)
binder_release_work(proc, &proc->todo);
binder_release_work(proc, &proc->delivered_death);
+ binder_release_work(proc, &proc->delivered_freeze);
binder_debug(BINDER_DEBUG_OPEN_CLOSE,
"%s: %d threads %d, nodes %d (ref %d), refs %d, active transactions %d\n",
--
2.46.1.824.gd892dcdcdd-goog
