[SRU][N][PATCH 1/2] Bluetooth: MGMT: Fix UAF on mgmt_remove_adv_monitor_complete
Massimiliano Pellizzer
massimiliano.pellizzer at canonical.com
Thu Oct 2 12:38:44 UTC 2025
From: Luiz Augusto von Dentz <luiz.von.dentz at intel.com>
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 at syzkaller.appspotmail.com
Tested-by: syzbot+feb0dc579bbe30a13190 at syzkaller.appspotmail.com
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz at intel.com>
(cherry picked from commit e6ed54e86aae9e4f7286ce8d5c73780f91b48d1c)
CVE-2025-38118
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer at canonical.com>
---
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 69baad48e82df..14f8729589575 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -2364,7 +2364,6 @@ 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 f9117e53a9e68..0812a5bb106d9 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1871,10 +1871,8 @@ 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 16061f348c9e5..381dc191e2488 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -5166,24 +5166,14 @@ 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,
@@ -5285,8 +5275,7 @@ 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;
}
@@ -5456,8 +5445,7 @@ 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);
@@ -5466,12 +5454,14 @@ 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",
@@ -5481,10 +5471,6 @@ 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);
@@ -5503,14 +5489,13 @@ 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;
@@ -5520,7 +5505,7 @@ 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;
--
2.48.1
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