[PATCH 6.12 423/512] Bluetooth: MGMT: Fix UAF on mgmt_remove_adv_monitor_complete

6.12-stable review patch. If anyone has any objections, please let me know.

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From: Luiz Augusto von Dentz luiz.von.dentz@intel.com

[ Upstream commit e6ed54e86aae9e4f7286ce8d5c73780f91b48d1c ]

This reworks MGMT_OP_REMOVE_ADV_MONITOR to not use mgmt_pending_add to avoid crashes like bellow:

================================================================== BUG: KASAN: slab-use-after-free in mgmt_remove_adv_monitor_complete+0xe5/0x540 net/bluetooth/mgmt.c:5406 Read of size 8 at addr ffff88801c53f318 by task kworker/u5:5/5341

CPU: 0 UID: 0 PID: 5341 Comm: kworker/u5:5 Not tainted 6.15.0-syzkaller-10402-g4cb6c8af8591 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 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:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 mgmt_remove_adv_monitor_complete+0xe5/0x540 net/bluetooth/mgmt.c:5406 hci_cmd_sync_work+0x261/0x3a0 net/bluetooth/hci_sync.c:334 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 arch/x86/entry/entry_64.S:245 </TASK>

Allocated by task 5987: 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:4358 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] mgmt_pending_new+0x65/0x240 net/bluetooth/mgmt_util.c:252 mgmt_pending_add+0x34/0x120 net/bluetooth/mgmt_util.c:279 remove_adv_monitor+0x103/0x1b0 net/bluetooth/mgmt.c:5454 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:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 sock_write_iter+0x258/0x330 net/socket.c:1131 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x548/0xa90 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 5989: 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:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x18e/0x440 mm/slub.c:4841 mgmt_pending_foreach+0xc9/0x120 net/bluetooth/mgmt_util.c:242 mgmt_index_removed+0x10d/0x2f0 net/bluetooth/mgmt.c:9366 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314 __sys_bind_socket net/socket.c:1810 [inline] __sys_bind+0x2c3/0x3e0 net/socket.c:1841 __do_sys_bind net/socket.c:1846 [inline] __se_sys_bind net/socket.c:1844 [inline] __x64_sys_bind+0x7a/0x90 net/socket.c:1844 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: 66bd095ab5d4 ("Bluetooth: advmon offload MSFT remove monitor") Closes: https://syzkaller.appspot.com/bug?extid=feb0dc579bbe30a13190 Reported-by: syzbot+feb0dc579bbe30a13190@syzkaller.appspotmail.com Tested-by: syzbot+feb0dc579bbe30a13190@syzkaller.appspotmail.com Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/bluetooth/hci_core.h | 1 - net/bluetooth/hci_core.c | 4 +--- net/bluetooth/mgmt.c | 37 ++++++++++---------------------- 3 files changed, 12 insertions(+), 30 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index 4f3b537476e10..d81c3f7dd328e 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -2379,7 +2379,6 @@ void mgmt_advertising_added(struct sock *sk, struct hci_dev *hdev, u8 instance); void mgmt_advertising_removed(struct sock *sk, struct hci_dev *hdev, u8 instance); -void mgmt_adv_monitor_removed(struct hci_dev *hdev, u16 handle); int mgmt_phy_configuration_changed(struct hci_dev *hdev, struct sock *skip); void mgmt_adv_monitor_device_lost(struct hci_dev *hdev, u16 handle, bdaddr_t *bdaddr, u8 addr_type); diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 831f41f6bc6de..77fceec9039ed 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -1877,10 +1877,8 @@ void hci_free_adv_monitor(struct hci_dev *hdev, struct adv_monitor *monitor) if (monitor->handle) idr_remove(&hdev->adv_monitors_idr, monitor->handle);

- if (monitor->state != ADV_MONITOR_STATE_NOT_REGISTERED) { + if (monitor->state != ADV_MONITOR_STATE_NOT_REGISTERED) hdev->adv_monitors_cnt--; - mgmt_adv_monitor_removed(hdev, monitor->handle); - }

kfree(monitor); } diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index d4700f940e8a1..7a086a9ad41fa 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -5172,24 +5172,14 @@ static void mgmt_adv_monitor_added(struct sock *sk, struct hci_dev *hdev, mgmt_event(MGMT_EV_ADV_MONITOR_ADDED, hdev, &ev, sizeof(ev), sk); }

-void mgmt_adv_monitor_removed(struct hci_dev *hdev, u16 handle) +static void mgmt_adv_monitor_removed(struct sock *sk, struct hci_dev *hdev, + u16 handle) { struct mgmt_ev_adv_monitor_removed ev; - struct mgmt_pending_cmd *cmd; - struct sock *sk_skip = NULL; - struct mgmt_cp_remove_adv_monitor *cp; - - cmd = pending_find(MGMT_OP_REMOVE_ADV_MONITOR, hdev); - if (cmd) { - cp = cmd->param; - - if (cp->monitor_handle) - sk_skip = cmd->sk; - }

ev.monitor_handle = cpu_to_le16(handle);

- mgmt_event(MGMT_EV_ADV_MONITOR_REMOVED, hdev, &ev, sizeof(ev), sk_skip); + mgmt_event(MGMT_EV_ADV_MONITOR_REMOVED, hdev, &ev, sizeof(ev), sk); }

static int read_adv_mon_features(struct sock *sk, struct hci_dev *hdev, @@ -5291,8 +5281,7 @@ static int __add_adv_patterns_monitor(struct sock *sk, struct hci_dev *hdev,

if (pending_find(MGMT_OP_SET_LE, hdev) || pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR, hdev) || - pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR_RSSI, hdev) || - pending_find(MGMT_OP_REMOVE_ADV_MONITOR, hdev)) { + pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR_RSSI, hdev)) { status = MGMT_STATUS_BUSY; goto unlock; } @@ -5462,8 +5451,7 @@ static void mgmt_remove_adv_monitor_complete(struct hci_dev *hdev, struct mgmt_pending_cmd *cmd = data; struct mgmt_cp_remove_adv_monitor *cp;

- if (status == -ECANCELED || - cmd != pending_find(MGMT_OP_REMOVE_ADV_MONITOR, hdev)) + if (status == -ECANCELED) return;

hci_dev_lock(hdev); @@ -5472,12 +5460,14 @@ static void mgmt_remove_adv_monitor_complete(struct hci_dev *hdev,

rp.monitor_handle = cp->monitor_handle;

- if (!status) + if (!status) { + mgmt_adv_monitor_removed(cmd->sk, hdev, cp->monitor_handle); hci_update_passive_scan(hdev); + }

mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode, mgmt_status(status), &rp, sizeof(rp)); - mgmt_pending_remove(cmd); + mgmt_pending_free(cmd);

hci_dev_unlock(hdev); bt_dev_dbg(hdev, "remove monitor %d complete, status %d", @@ -5487,10 +5477,6 @@ static void mgmt_remove_adv_monitor_complete(struct hci_dev *hdev, static int mgmt_remove_adv_monitor_sync(struct hci_dev *hdev, void *data) { struct mgmt_pending_cmd *cmd = data; - - if (cmd != pending_find(MGMT_OP_REMOVE_ADV_MONITOR, hdev)) - return -ECANCELED; - struct mgmt_cp_remove_adv_monitor *cp = cmd->param; u16 handle = __le16_to_cpu(cp->monitor_handle);

@@ -5509,14 +5495,13 @@ static int remove_adv_monitor(struct sock *sk, struct hci_dev *hdev, hci_dev_lock(hdev);

if (pending_find(MGMT_OP_SET_LE, hdev) || - pending_find(MGMT_OP_REMOVE_ADV_MONITOR, hdev) || pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR, hdev) || pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR_RSSI, hdev)) { status = MGMT_STATUS_BUSY; goto unlock; }

- cmd = mgmt_pending_add(sk, MGMT_OP_REMOVE_ADV_MONITOR, hdev, data, len); + cmd = mgmt_pending_new(sk, MGMT_OP_REMOVE_ADV_MONITOR, hdev, data, len); if (!cmd) { status = MGMT_STATUS_NO_RESOURCES; goto unlock; @@ -5526,7 +5511,7 @@ static int remove_adv_monitor(struct sock *sk, struct hci_dev *hdev, mgmt_remove_adv_monitor_complete);

if (err) { - mgmt_pending_remove(cmd); + mgmt_pending_free(cmd);

if (err == -ENOMEM) status = MGMT_STATUS_NO_RESOURCES;