diff options
| author | Ying Hsu <yinghsu@chromium.org> | 2023-07-05 21:06:47 +0000 |
|---|---|---|
| committer | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2023-08-11 11:48:20 -0700 |
| commit | 573ebae162111063eedc6c838a659ba628f66a0f (patch) | |
| tree | da63e863d0a820c8f7ad42ef2e2be06fe1d3f32f | |
| parent | 9c33663af9ad115f90c076a1828129a3fbadea98 (diff) | |
Bluetooth: Fix hci_suspend_sync crash
If hci_unregister_dev() frees the hci_dev object but hci_suspend_notifier
may still be accessing it, it can cause the program to crash.
Here's the call trace:
<4>[102152.653246] Call Trace:
<4>[102152.653254] hci_suspend_sync+0x109/0x301 [bluetooth]
<4>[102152.653259] hci_suspend_dev+0x78/0xcd [bluetooth]
<4>[102152.653263] hci_suspend_notifier+0x42/0x7a [bluetooth]
<4>[102152.653268] notifier_call_chain+0x43/0x6b
<4>[102152.653271] __blocking_notifier_call_chain+0x48/0x69
<4>[102152.653273] __pm_notifier_call_chain+0x22/0x39
<4>[102152.653276] pm_suspend+0x287/0x57c
<4>[102152.653278] state_store+0xae/0xe5
<4>[102152.653281] kernfs_fop_write+0x109/0x173
<4>[102152.653284] __vfs_write+0x16f/0x1a2
<4>[102152.653287] ? selinux_file_permission+0xca/0x16f
<4>[102152.653289] ? security_file_permission+0x36/0x109
<4>[102152.653291] vfs_write+0x114/0x21d
<4>[102152.653293] __x64_sys_write+0x7b/0xdb
<4>[102152.653296] do_syscall_64+0x59/0x194
<4>[102152.653299] entry_SYSCALL_64_after_hwframe+0x5c/0xc1
This patch holds the reference count of the hci_dev object while
processing it in hci_suspend_notifier to avoid potential crash
caused by the race condition.
Signed-off-by: Ying Hsu <yinghsu@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
| -rw-r--r-- | net/bluetooth/hci_core.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 821ae737e85b..bd90caad4804 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2436,6 +2436,9 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action, if (hci_dev_test_flag(hdev, HCI_USER_CHANNEL)) return NOTIFY_DONE; + /* To avoid a potential race with hci_unregister_dev. */ + hci_dev_hold(hdev); + if (action == PM_SUSPEND_PREPARE) ret = hci_suspend_dev(hdev); else if (action == PM_POST_SUSPEND) @@ -2445,6 +2448,7 @@ static int hci_suspend_notifier(struct notifier_block *nb, unsigned long action, bt_dev_err(hdev, "Suspend notifier action (%lu) failed: %d", action, ret); + hci_dev_put(hdev); return NOTIFY_DONE; } |