* [PATCH] Bluetooth: mgmt: copy pending command data under the list lock
@ 2026-06-18 10:21 Cen Zhang
2026-06-18 13:20 ` bluez.test.bot
0 siblings, 1 reply; 2+ messages in thread
From: Cen Zhang @ 2026-06-18 10:21 UTC (permalink / raw)
To: Marcel Holtmann, Luiz Augusto von Dentz
Cc: linux-bluetooth, linux-kernel, baijiaju1990, zzzccc427
mgmt_pending_find() only protects the pending list lookup. Once it
returns, a caller that dereferences the returned command has no lifetime
guarantee unless another lock or ownership transfer keeps the command from
being removed and freed.
mgmt_powering_down() only needs the requested SET_POWERED mode, but it
currently keeps the raw pending command pointer after the list lock has
been dropped and then reads cmd->param and cp->val.
The buggy scenario involves two paths, with each column showing the order
within that path:
hci_suspend_dev()/hci_resume_dev(): SET_POWERED completion:
1. mgmt_powering_down() calls 1. mgmt_set_powered_complete()
pending_find()
2. pending_find() drops 2. mgmt_pending_valid() delists
mgmt_pending_lock the command
3. mgmt_pending_free() frees the
command and parameter buffer
3. mgmt_powering_down() reads
cmd->param
4. mgmt_powering_down() reads
cp->val
Add a helper that copies a requested pending-command parameter slice while
mgmt_pending_lock is still held. Use it for the mgmt_mode readers in
mgmt.c so they take a snapshot of the pending request instead of keeping an
unlocked raw command pointer just to inspect the requested mode.
Validation reproduced this kernel report:
BUG: KASAN: slab-use-after-free in mgmt_powering_down+0xa0/0xf0
Call Trace:
<TASK>
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x5f0
? mgmt_powering_down+0xa0/0xf0
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x19f/0x330
? mgmt_powering_down+0xa0/0xf0
kasan_report+0xe0/0x110
? mgmt_powering_down+0xa0/0xf0
mgmt_powering_down+0xa0/0xf0
hci_suspend_dev+0xc0/0x2d0
? vhci_suspend_work+0x31/0x50
process_one_work+0x4fd/0xbc0
? __pfx_process_one_work+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? __list_add_valid_or_report+0x37/0xf0
? __pfx_vhci_suspend_work+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
worker_thread+0x2d8/0x570
? srso_alias_return_thunk+0x5/0xfbef5
? __pfx_worker_thread+0x10/0x10
kthread+0x1ad/0x1f0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x3c9/0x540
? __pfx_ret_from_fork+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? __switch_to+0x2e9/0x730
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 336 on cpu 2 at 98.764916s:
kasan_save_stack+0x33/0x60
kasan_save_track+0x17/0x60
__kasan_kmalloc+0xaa/0xb0
mgmt_pending_new+0x44/0x130
mgmt_pending_add+0x22/0x110
set_powered+0x1ad/0x310
hci_sock_sendmsg+0x96b/0xf80
sock_write_iter+0x28e/0x2a0
do_iter_readv_writev+0x211/0x390
vfs_writev+0x266/0x7b0
do_writev+0x191/0x1d0
do_syscall_64+0x115/0x6a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 314 on cpu 0 at 101.816391s:
kasan_save_stack+0x33/0x60
kasan_save_track+0x17/0x60
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x5f/0x80
kfree+0x313/0x590
mgmt_pending_foreach+0x144/0x190
__mgmt_power_off+0xca/0x250
hci_dev_close_sync+0x8ba/0xb00
hci_set_powered_sync+0x384/0x480
hci_cmd_sync_work+0x187/0x210
process_one_work+0x4fd/0xbc0
worker_thread+0x2d8/0x570
kthread+0x1ad/0x1f0
ret_from_fork+0x3c9/0x540
ret_from_fork_asm+0x1a/0x30
Assisted-by: Codex:gpt-5.5
Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
---
net/bluetooth/mgmt.c | 37 ++++++++++++++++++-------------------
net/bluetooth/mgmt_util.c | 27 +++++++++++++++++++++++++++
net/bluetooth/mgmt_util.h | 2 ++
3 files changed, 47 insertions(+), 19 deletions(-)
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index d23ca1dd0893..91272640864a 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -960,19 +960,25 @@ static struct mgmt_pending_cmd *pending_find(u16 opcode, struct hci_dev *hdev)
return mgmt_pending_find(HCI_CHANNEL_CONTROL, opcode, hdev);
}
+static bool pending_find_copy(u16 opcode, struct hci_dev *hdev, void *data,
+ size_t len)
+{
+ return mgmt_pending_find_copy(HCI_CHANNEL_CONTROL, opcode, hdev,
+ data, len);
+}
+
u8 mgmt_get_adv_discov_flags(struct hci_dev *hdev)
{
- struct mgmt_pending_cmd *cmd;
+ struct mgmt_mode cp;
/* If there's a pending mgmt command the flags will not yet have
* their final values, so check for this first.
*/
- cmd = pending_find(MGMT_OP_SET_DISCOVERABLE, hdev);
- if (cmd) {
- struct mgmt_mode *cp = cmd->param;
- if (cp->val == 0x01)
+ if (pending_find_copy(MGMT_OP_SET_DISCOVERABLE, hdev, &cp,
+ sizeof(cp))) {
+ if (cp.val == 0x01)
return LE_AD_GENERAL;
- else if (cp->val == 0x02)
+ else if (cp.val == 0x02)
return LE_AD_LIMITED;
} else {
if (hci_dev_test_flag(hdev, HCI_LIMITED_DISCOVERABLE))
@@ -986,17 +992,13 @@ u8 mgmt_get_adv_discov_flags(struct hci_dev *hdev)
bool mgmt_get_connectable(struct hci_dev *hdev)
{
- struct mgmt_pending_cmd *cmd;
+ struct mgmt_mode cp;
/* If there's a pending mgmt command the flag will not yet have
* it's final value, so check for this first.
*/
- cmd = pending_find(MGMT_OP_SET_CONNECTABLE, hdev);
- if (cmd) {
- struct mgmt_mode *cp = cmd->param;
-
- return cp->val;
- }
+ if (pending_find_copy(MGMT_OP_SET_CONNECTABLE, hdev, &cp, sizeof(cp)))
+ return cp.val;
return hci_dev_test_flag(hdev, HCI_CONNECTABLE);
}
@@ -9826,18 +9828,15 @@ static void unpair_device_rsp(struct mgmt_pending_cmd *cmd, void *data)
bool mgmt_powering_down(struct hci_dev *hdev)
{
- struct mgmt_pending_cmd *cmd;
- struct mgmt_mode *cp;
+ struct mgmt_mode cp;
if (hci_dev_test_flag(hdev, HCI_POWERING_DOWN))
return true;
- cmd = pending_find(MGMT_OP_SET_POWERED, hdev);
- if (!cmd)
+ if (!pending_find_copy(MGMT_OP_SET_POWERED, hdev, &cp, sizeof(cp)))
return false;
- cp = cmd->param;
- if (!cp->val)
+ if (!cp.val)
return true;
return false;
diff --git a/net/bluetooth/mgmt_util.c b/net/bluetooth/mgmt_util.c
index 6ea107c0e054..5d6d13ccadd2 100644
--- a/net/bluetooth/mgmt_util.c
+++ b/net/bluetooth/mgmt_util.c
@@ -233,6 +233,33 @@ struct mgmt_pending_cmd *mgmt_pending_find(unsigned short channel, u16 opcode,
return NULL;
}
+bool mgmt_pending_find_copy(unsigned short channel, u16 opcode,
+ struct hci_dev *hdev, void *data, size_t len)
+{
+ struct mgmt_pending_cmd *cmd, *tmp;
+ bool found = false;
+
+ mutex_lock(&hdev->mgmt_pending_lock);
+
+ list_for_each_entry_safe(cmd, tmp, &hdev->mgmt_pending, list) {
+ if (hci_sock_get_channel(cmd->sk) != channel)
+ continue;
+
+ if (cmd->opcode != opcode)
+ continue;
+
+ if (cmd->param_len >= len) {
+ memcpy(data, cmd->param, len);
+ found = true;
+ }
+ break;
+ }
+
+ mutex_unlock(&hdev->mgmt_pending_lock);
+
+ return found;
+}
+
void mgmt_pending_foreach(u16 opcode, struct hci_dev *hdev, bool remove,
void (*cb)(struct mgmt_pending_cmd *cmd, void *data),
void *data)
diff --git a/net/bluetooth/mgmt_util.h b/net/bluetooth/mgmt_util.h
index 20810cf06e81..4cccb71c8a1f 100644
--- a/net/bluetooth/mgmt_util.h
+++ b/net/bluetooth/mgmt_util.h
@@ -51,6 +51,8 @@ int mgmt_cmd_complete(struct sock *sk, u16 index, u16 cmd, u8 status,
struct mgmt_pending_cmd *mgmt_pending_find(unsigned short channel, u16 opcode,
struct hci_dev *hdev);
+bool mgmt_pending_find_copy(unsigned short channel, u16 opcode,
+ struct hci_dev *hdev, void *data, size_t len);
void mgmt_pending_foreach(u16 opcode, struct hci_dev *hdev, bool remove,
void (*cb)(struct mgmt_pending_cmd *cmd, void *data),
void *data);
--
2.43.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* RE: Bluetooth: mgmt: copy pending command data under the list lock
2026-06-18 10:21 [PATCH] Bluetooth: mgmt: copy pending command data under the list lock Cen Zhang
@ 2026-06-18 13:20 ` bluez.test.bot
0 siblings, 0 replies; 2+ messages in thread
From: bluez.test.bot @ 2026-06-18 13:20 UTC (permalink / raw)
To: linux-bluetooth, zzzccc427
[-- Attachment #1: Type: text/plain, Size: 3087 bytes --]
This is automated email and please do not reply to this email!
Dear submitter,
Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1113386
---Test result---
Test Summary:
CheckPatch FAIL 1.09 seconds
VerifyFixes PASS 0.10 seconds
VerifySignedoff PASS 0.10 seconds
GitLint PASS 0.26 seconds
SubjectPrefix PASS 0.09 seconds
BuildKernel PASS 27.00 seconds
CheckAllWarning PASS 29.02 seconds
CheckSparse PASS 28.07 seconds
BuildKernel32 PASS 25.88 seconds
CheckKernelLLVM SKIP 0.00 seconds
TestRunnerSetup PASS 575.19 seconds
TestRunner_l2cap-tester PASS 57.33 seconds
TestRunner_iso-tester PASS 77.04 seconds
TestRunner_bnep-tester PASS 18.66 seconds
TestRunner_mgmt-tester FAIL 207.50 seconds
TestRunner_rfcomm-tester PASS 25.16 seconds
TestRunner_sco-tester PASS 31.86 seconds
TestRunner_ioctl-tester PASS 25.58 seconds
TestRunner_mesh-tester FAIL 25.86 seconds
TestRunner_smp-tester PASS 22.94 seconds
TestRunner_userchan-tester PASS 20.24 seconds
TestRunner_6lowpan-tester PASS 22.17 seconds
IncrementalBuild PASS 25.48 seconds
Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
Bluetooth: mgmt: copy pending command data under the list lock
WARNING: The commit message has 'Call Trace:', perhaps it also needs a 'Fixes:' tag?
total: 0 errors, 1 warnings, 0 checks, 113 lines checked
NOTE: For some of the reported defects, checkpatch may be able to
mechanically convert to the typical style using --fix or --fix-inplace.
/github/workspace/src/patch/14635032.patch has style problems, please review.
NOTE: Ignored message types: UNKNOWN_COMMIT_ID
NOTE: If any of the errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
##############################
Test: CheckKernelLLVM - SKIP
Desc: Build kernel with LLVM + context analysis
Output:
Clang not found
##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4
Failed Test Cases
Read Exp Feature - Success Failed 0.237 seconds
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0
Failed Test Cases
Mesh - Send cancel - 1 Timed out 2.645 seconds
Mesh - Send cancel - 2 Timed out 1.990 seconds
https://github.com/bluez/bluetooth-next/pull/331
---
Regards,
Linux Bluetooth
^ permalink raw reply [flat|nested] 2+ messages in thread
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