syzbot reports a slab use-after-free in hci_conn_hash_flush [1].
After releasing an object using hci_conn_del_sysfs in the
hci_conn_cleanup function, releasing the same object again
using the hci_dev_put and hci_conn_put functions causes a double free.
Here's a simplified flow:
hci_conn_del_sysfs:
hci_dev_put
put_device
kobject_put
kref_put
kobject_release
kobject_cleanup
kfree_const
kfree(name)
hci_dev_put:
...
kfree(name)
hci_conn_put:
put_device
...
kfree(name)
This patch drop the hci_dev_put and hci_conn_put function
call in hci_conn_cleanup function, because the object is
freed in hci_conn_del_sysfs function.
Link: https://syzkaller.appspot.com/bug?id=1bb51491ca5df96a5f724899d1dbb87afda61419 [1]
Signed-off-by: ZhengHan Wang <[email protected]>
---
net/bluetooth/hci_conn.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index acf563fbdfd9..a0ccbef34bc2 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -152,10 +152,6 @@ static void hci_conn_cleanup(struct hci_conn *conn)
hci_conn_del_sysfs(conn);
debugfs_remove_recursive(conn->debugfs);
-
- hci_dev_put(hdev);
-
- hci_conn_put(conn);
}
static void le_scan_cleanup(struct work_struct *work)
--
2.25.1
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=728135
---Test result---
Test Summary:
CheckPatch PASS 0.79 seconds
GitLint FAIL 0.66 seconds
SubjectPrefix PASS 0.13 seconds
BuildKernel PASS 46.02 seconds
CheckAllWarning PASS 50.61 seconds
CheckSparse PASS 56.37 seconds
CheckSmatch PASS 151.79 seconds
BuildKernel32 PASS 44.10 seconds
TestRunnerSetup PASS 629.37 seconds
TestRunner_l2cap-tester PASS 20.59 seconds
TestRunner_iso-tester PASS 22.83 seconds
TestRunner_bnep-tester PASS 8.18 seconds
TestRunner_mgmt-tester FAIL 146.90 seconds
TestRunner_rfcomm-tester PASS 12.44 seconds
TestRunner_sco-tester PASS 11.54 seconds
TestRunner_ioctl-tester FAIL 13.13 seconds
TestRunner_mesh-tester PASS 10.25 seconds
TestRunner_smp-tester PASS 10.93 seconds
TestRunner_userchan-tester PASS 8.58 seconds
IncrementalBuild PASS 41.29 seconds
Details
##############################
Test: GitLint - FAIL
Desc: Run gitlint
Output:
Bluetooth: Fix double free in hci_conn_cleanup
WARNING: I3 - ignore-body-lines: gitlint will be switching from using Python regex 'match' (match beginning) to 'search' (match anywhere) semantics. Please review your ignore-body-lines.regex option accordingly. To remove this warning, set general.regex-style-search=True. More details: https://jorisroovers.github.io/gitlint/configuration/#regex-style-search
4: B2 Line has trailing whitespace: "After releasing an object using hci_conn_del_sysfs in the "
5: B2 Line has trailing whitespace: "hci_conn_cleanup function, releasing the same object again "
28: B2 Line has trailing whitespace: "This patch drop the hci_dev_put and hci_conn_put function "
29: B2 Line has trailing whitespace: "call in hci_conn_cleanup function, because the object is "
32: B1 Line exceeds max length (87>80): "Link: https://syzkaller.appspot.com/bug?id=1bb51491ca5df96a5f724899d1dbb87afda61419 [1]"
##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 5, Not Run: 0
Failed Test Cases
Read Ext Controller Info 1 Failed 0.168 seconds
Read Ext Controller Info 2 Failed 0.196 seconds
Read Ext Controller Info 3 Failed 0.172 seconds
Read Ext Controller Info 4 Failed 0.184 seconds
Read Ext Controller Info 5 Failed 0.220 seconds
##############################
Test: TestRunner_ioctl-tester - FAIL
Desc: Run ioctl-tester with test-runner
Output:
No test result found
---
Regards,
Linux Bluetooth