From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> BUG: KASAN: slab-use-after-free in mgmt_add_adv_patterns_monitor_sync+0x35/0x50 net/bluetooth/mgmt.c:5223 Read of size 8 at addr ffff8880709d4dc0 by task kworker/u11:0/55 CPU: 0 UID: 0 PID: 55 Comm: kworker/u11:0 Not tainted 6.16.4 #2 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Workqueue: hci0 hci_cmd_sync_work Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 mgmt_add_adv_patterns_monitor_sync+0x35/0x50 net/bluetooth/mgmt.c:5223 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16.4/arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 12210: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4364 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] mgmt_pending_new+0x65/0x1e0 net/bluetooth/mgmt_util.c:269 mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296 __add_adv_patterns_monitor+0x130/0x200 net/bluetooth/mgmt.c:5247 add_adv_patterns_monitor+0x214/0x360 net/bluetooth/mgmt.c:5364 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 sock_write_iter+0x258/0x330 net/socket.c:1133 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12221: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4648 [inline] kfree+0x18e/0x440 mm/slub.c:4847 mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline] mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257 __mgmt_power_off+0x169/0x350 net/bluetooth/mgmt.c:9444 hci_dev_close_sync+0x754/0x1330 net/bluetooth/hci_sync.c:5290 hci_dev_do_close net/bluetooth/hci_core.c:501 [inline] hci_dev_close+0x108/0x200 net/bluetooth/hci_core.c:526 sock_do_ioctl+0xd9/0x300 net/socket.c:1192 sock_ioctl+0x576/0x790 net/socket.c:1313 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: b747a83690c8 ("Bluetooth: hci_sync: Refactor add Adv Monitor") Closes: https://syzkaller.appspot.com/bug?extid=e8651419c44dbc2b8768 Reported-by: syzbot+e8651419c44dbc2b8768@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> --- net/bluetooth/mgmt.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 989321b1ea27..d76aa3eda37f 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -5189,6 +5189,14 @@ static void mgmt_add_adv_patterns_monitor_complete(struct hci_dev *hdev, struct mgmt_pending_cmd *cmd = data; struct adv_monitor *monitor = cmd->user_data; + /* This is likely the result of hdev being closed and mgmt_index_removed + * is attempting to clean up any pending command so + * hci_adv_monitors_clear is about to be called which will take care of + * freeing the adv_monitor instances. + */ + if (status == -ECANCELED) + return; + hci_dev_lock(hdev); rp.monitor_handle = cpu_to_le16(monitor->handle); @@ -5213,9 +5221,12 @@ static void mgmt_add_adv_patterns_monitor_complete(struct hci_dev *hdev, static int mgmt_add_adv_patterns_monitor_sync(struct hci_dev *hdev, void *data) { struct mgmt_pending_cmd *cmd = data; - struct adv_monitor *monitor = cmd->user_data; - return hci_add_adv_monitor(hdev, monitor); + if (cmd != pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR, hdev) && + cmd != pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR_RSSI, hdev)) + return -ECANCELED; + + return hci_add_adv_monitor(hdev, cmd->user_data); } static int __add_adv_patterns_monitor(struct sock *sk, struct hci_dev *hdev, -- 2.51.0