From d236517c264e41dc09833c708ef23bccb7a91219 Mon Sep 17 00:00:00 2001 From: Weiming Shi Date: Sun, 6 Sep 2026 23:43:32 +0800 Subject: [PATCH] Bluetooth: coredump: Quiesce dump work on unregister hci_devcd_handle_pkt_init() arms dump_timeout and coredump producers queue dump_rx without holding an hdev reference. Unregister leaves both works live, so disconnecting during an active dump lets them access hdev after hci_release_dev() frees it. Shut down coredump processing during unregister. Close the producer gate under dump_q.lock before disabling both works, then free the active buffer and queued packets under hci_dev_lock. Serializing the gate with enqueue prevents controller-specific workers from adding packets after the final purge. Fixes: 9695ef876fd1 ("Bluetooth: Add support for hci devcoredump") Reported-by: syzbot+b170dbf55520ebf5969a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b170dbf55520ebf5969a Reported-by: Aby Sam Ross Link: https://lore.kernel.org/r/20260322210849.68743-1-abysamross@gmail.com Suggested-by: Aby Sam Ross Reported-by: Tristan Madani Link: https://lore.kernel.org/r/20260814231248.3096377-1-tristmd@gmail.com Reported-by: Xiang Mei Assisted-by: OpenAI Codex:gpt-5 Signed-off-by: Weiming Shi Reported-by: Xiang Mei Signed-off-by: Luiz Augusto von Dentz --- include/net/bluetooth/coredump.h | 2 + net/bluetooth/coredump.c | 65 +++++++++++++++++++++----------- net/bluetooth/hci_core.c | 1 + 3 files changed, 47 insertions(+), 21 deletions(-) diff --git a/include/net/bluetooth/coredump.h b/include/net/bluetooth/coredump.h index 1f071ab55416..acc1849f66c0 100644 --- a/include/net/bluetooth/coredump.h +++ b/include/net/bluetooth/coredump.h @@ -70,6 +70,7 @@ struct hci_devcoredump { const char *hci_devcd_state_name(enum devcoredump_state state); void hci_devcd_reset(struct hci_dev *hdev); +void hci_devcd_shutdown(struct hci_dev *hdev); void hci_devcd_rx(struct work_struct *work); void hci_devcd_timeout(struct work_struct *work); @@ -89,6 +90,7 @@ static inline const char *hci_devcd_state_name(enum devcoredump_state state) } static inline void hci_devcd_reset(struct hci_dev *hdev) {} +static inline void hci_devcd_shutdown(struct hci_dev *hdev) {} static inline void hci_devcd_rx(struct work_struct *work) {} static inline void hci_devcd_timeout(struct work_struct *work) {} diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c index 5bee863bd6d2..71fc8dab4004 100644 --- a/net/bluetooth/coredump.c +++ b/net/bluetooth/coredump.c @@ -104,6 +104,22 @@ static void hci_devcd_free(struct hci_dev *hdev) hci_devcd_reset(hdev); } +void hci_devcd_shutdown(struct hci_dev *hdev) +{ + unsigned long flags; + + spin_lock_irqsave(&hdev->dump.dump_q.lock, flags); + hdev->dump.supported = false; + spin_unlock_irqrestore(&hdev->dump.dump_q.lock, flags); + + disable_work_sync(&hdev->dump.dump_rx); + disable_delayed_work_sync(&hdev->dump.dump_timeout); + + hci_dev_lock(hdev); + hci_devcd_free(hdev); + hci_dev_unlock(hdev); +} + /* Call with hci_dev_lock only. */ static int hci_devcd_alloc(struct hci_dev *hdev, u32 size) { @@ -442,7 +458,29 @@ EXPORT_SYMBOL(hci_devcd_register); static inline bool hci_devcd_enabled(struct hci_dev *hdev) { - return hdev->dump.supported; + return READ_ONCE(hdev->dump.supported); +} + +static int hci_devcd_queue(struct hci_dev *hdev, struct sk_buff *skb) +{ + unsigned long flags; + int err = 0; + + spin_lock_irqsave(&hdev->dump.dump_q.lock, flags); + if (!hdev->dump.supported) + err = -EOPNOTSUPP; + else + __skb_queue_tail(&hdev->dump.dump_q, skb); + spin_unlock_irqrestore(&hdev->dump.dump_q.lock, flags); + + if (err) { + kfree_skb(skb); + return err; + } + + queue_work(hdev->workqueue, &hdev->dump.dump_rx); + + return 0; } int hci_devcd_init(struct hci_dev *hdev, u32 dump_size) @@ -459,10 +497,7 @@ int hci_devcd_init(struct hci_dev *hdev, u32 dump_size) hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_INIT; put_unaligned_le32(dump_size, skb_put(skb, 4)); - skb_queue_tail(&hdev->dump.dump_q, skb); - queue_work(hdev->workqueue, &hdev->dump.dump_rx); - - return 0; + return hci_devcd_queue(hdev, skb); } EXPORT_SYMBOL(hci_devcd_init); @@ -478,10 +513,7 @@ int hci_devcd_append(struct hci_dev *hdev, struct sk_buff *skb) hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_SKB; - skb_queue_tail(&hdev->dump.dump_q, skb); - queue_work(hdev->workqueue, &hdev->dump.dump_rx); - - return 0; + return hci_devcd_queue(hdev, skb); } EXPORT_SYMBOL(hci_devcd_append); @@ -503,10 +535,7 @@ int hci_devcd_append_pattern(struct hci_dev *hdev, u8 pattern, u32 len) hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_PATTERN; skb_put_data(skb, &p, sizeof(p)); - skb_queue_tail(&hdev->dump.dump_q, skb); - queue_work(hdev->workqueue, &hdev->dump.dump_rx); - - return 0; + return hci_devcd_queue(hdev, skb); } EXPORT_SYMBOL(hci_devcd_append_pattern); @@ -523,10 +552,7 @@ int hci_devcd_complete(struct hci_dev *hdev) hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_COMPLETE; - skb_queue_tail(&hdev->dump.dump_q, skb); - queue_work(hdev->workqueue, &hdev->dump.dump_rx); - - return 0; + return hci_devcd_queue(hdev, skb); } EXPORT_SYMBOL(hci_devcd_complete); @@ -543,10 +569,7 @@ int hci_devcd_abort(struct hci_dev *hdev) hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_ABORT; - skb_queue_tail(&hdev->dump.dump_q, skb); - queue_work(hdev->workqueue, &hdev->dump.dump_rx); - - return 0; + return hci_devcd_queue(hdev, skb); } EXPORT_SYMBOL(hci_devcd_abort); diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index c322e4736621..d183efaf9063 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -2673,6 +2673,7 @@ void hci_unregister_dev(struct hci_dev *hdev) disable_work_sync(&hdev->error_reset); disable_delayed_work_sync(&hdev->cmd_timer); disable_delayed_work_sync(&hdev->ncmd_timer); + hci_devcd_shutdown(hdev); hci_cmd_sync_clear(hdev);