[PATCH v2] Bluetooth: fix memory leak in error path of hci_alloc_dev()

[PATCH v2] Bluetooth: fix memory leak in error path of hci_alloc_dev()

[Bharath Reddy]

Early failures in Bluetooth HCI UART configuration leak SRCU percpu
memory.

When device initialization fails before hci_register_dev() completes,
the HCI_UNREGISTER flag is never set. As a result, when the device
reference count reaches zero, bt_host_release() evaluates this flag as
false and falls back to a direct kfree(hdev).

Because hci_release_dev() is bypassed, the SRCU struct initialized
early in hci_alloc_dev() is never cleaned up, resulting in a leak of
percpu memory.

Fix the leak by explicitly calling cleanup_srcu_struct() in the
fallback (unregistered) branch of bt_host_release() before freeing
the device.

Reported-by: syzbot+535ecc844591e50588a5@syzkaller.appspotmail.com
Tested-by: syzbot+535ecc844591e50588a5@syzkaller.appspotmail.com
Signed-off-by: Bharath Reddy <kbreddy.rpbc@gmail.com>
---
 net/bluetooth/hci_sysfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index 041ce9adc378..74131f2c3be6 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -85,8 +85,10 @@ static void bt_host_release(struct device *dev)
 
 	if (hci_dev_test_flag(hdev, HCI_UNREGISTER))
 		hci_release_dev(hdev);
-	else
+	else {
+		cleanup_srcu_struct(&hdev->srcu);
 		kfree(hdev);
+	}
 	module_put(THIS_MODULE);
 }
 
-- 
2.34.1

RE: [v2] Bluetooth: fix memory leak in error path of hci_alloc_dev()

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 3229 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=1103634

---Test result---

Test Summary:
CheckPatch                    FAIL      0.60 seconds
VerifyFixes                   PASS      0.09 seconds
VerifySignedoff               PASS      0.11 seconds
GitLint                       PASS      0.24 seconds
SubjectPrefix                 PASS      0.08 seconds
BuildKernel                   PASS      24.95 seconds
CheckAllWarning               PASS      27.43 seconds
CheckSparse                   PASS      26.70 seconds
BuildKernel32                 PASS      24.35 seconds
TestRunnerSetup               PASS      520.47 seconds
TestRunner_l2cap-tester       PASS      57.78 seconds
TestRunner_iso-tester         PASS      74.71 seconds
TestRunner_bnep-tester        PASS      19.35 seconds
TestRunner_mgmt-tester        FAIL      210.09 seconds
TestRunner_rfcomm-tester      PASS      25.18 seconds
TestRunner_sco-tester         PASS      32.15 seconds
TestRunner_ioctl-tester       PASS      26.43 seconds
TestRunner_mesh-tester        FAIL      25.90 seconds
TestRunner_smp-tester         PASS      23.34 seconds
TestRunner_userchan-tester    PASS      20.13 seconds
TestRunner_6lowpan-tester     PASS      22.82 seconds
IncrementalBuild              PASS      23.50 seconds

Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
[v2] Bluetooth: fix memory leak in error path of hci_alloc_dev()
WARNING: Reported-by: should be immediately followed by Closes: with a URL to the report
#116: 
Reported-by: syzbot+535ecc844591e50588a5@syzkaller.appspotmail.com
Tested-by: syzbot+535ecc844591e50588a5@syzkaller.appspotmail.com

CHECK: Unbalanced braces around else statement
#132: FILE: net/bluetooth/hci_sysfs.c:88:
+	else {

WARNING: The commit message has 'syzkaller', perhaps it also needs a 'Fixes:' tag?

total: 0 errors, 2 warnings, 1 checks, 11 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/14603853.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: 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       0.236 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    2.331 seconds
Mesh - Send cancel - 2                               Timed out    1.991 seconds


https://github.com/bluez/bluetooth-next/pull/260

---
Regards,
Linux Bluetooth

Re: [PATCH v2] Bluetooth: fix memory leak in error path of hci_alloc_dev()

[Markus Elfring]

…
> Fix the leak by explicitly calling cleanup_srcu_struct() in the
> fallback (unregistered) branch of bt_host_release() before freeing
> the device.
…
> ---
>  net/bluetooth/hci_sysfs.c | 4 +++-

Some contributors would appreciate patch version descriptions.
https://lore.kernel.org/all/?q=%22This+looks+like+a+new+version+of+a+previously+submitted+patch%22
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.1-rc5#n310

Regards,
Markus