6.12-stable review patch. If anyone has any objections, please let me know.
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From: Carlos Llamas cmllamas@google.com
commit 1db76ec2b4b206ff943e292a0b55e68ff3443598 upstream.
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@vger.kernel.org Signed-off-by: Carlos Llamas cmllamas@google.com Reviewed-by: Alice Ryhl aliceryhl@google.com Acked-by: Todd Kjos tkjos@google.com Link: https://lore.kernel.org/r/20240926233632.821189-8-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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",