[PATCH] Bluetooth: SCO: Fix use-after-free in sco_conn_ready() due to missing sock_hold

[PATCH] Bluetooth: SCO: Fix use-after-free in sco_conn_ready() due to missing sock_hold

[Hyunwoo Kim]

sco_get_sock_listen() returns a pointer to a listening socket without
incrementing its reference count. If the listening socket is concurrently
closed and freed before sco_conn_ready() calls lock_sock(parent), a
use-after-free occurs. The listening socket has no sco_conn association
(sco_pi(sk)->conn == NULL), so sco_conn_lock does not prevent it.

Fix by adding sock_hold()/sock_put() in sco_get_sock_listen() following
the iso_get_sock() pattern.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
---
 net/bluetooth/sco.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index e7db50165879..7ad6d9208de5 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -449,14 +449,23 @@ static struct sock *sco_get_sock_listen(bdaddr_t *src)
 			continue;
 
 		/* Exact match. */
-		if (!bacmp(&sco_pi(sk)->src, src))
+		if (!bacmp(&sco_pi(sk)->src, src)) {
+			sock_hold(sk);
 			break;
+		}
 
 		/* Closest match */
-		if (!bacmp(&sco_pi(sk)->src, BDADDR_ANY))
+		if (!bacmp(&sco_pi(sk)->src, BDADDR_ANY)) {
+			if (sk1)
+				sock_put(sk1);
 			sk1 = sk;
+			sock_hold(sk1);
+		}
 	}
 
+	if (sk && sk1)
+		sock_put(sk1);
+
 	read_unlock(&sco_sk_list.lock);
 
 	return sk ? sk : sk1;
@@ -1376,6 +1385,7 @@ static void sco_conn_ready(struct sco_conn *conn)
 		if (!sk) {
 			release_sock(parent);
 			sco_conn_unlock(conn);
+			sock_put(parent);
 			return;
 		}
 
@@ -1399,6 +1409,7 @@ static void sco_conn_ready(struct sco_conn *conn)
 		release_sock(parent);
 
 		sco_conn_unlock(conn);
+		sock_put(parent);
 	}
 }
 
-- 
2.43.0

RE: Bluetooth: SCO: Fix use-after-free in sco_conn_ready() due to missing sock_hold

[bluez.test.bot]

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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=1069343

---Test result---

Test Summary:
CheckPatch                    PENDING   0.45 seconds
GitLint                       PENDING   0.26 seconds
SubjectPrefix                 PASS      0.07 seconds
BuildKernel                   PASS      26.66 seconds
CheckAllWarning               PASS      29.30 seconds
CheckSparse                   PASS      28.05 seconds
BuildKernel32                 PASS      25.49 seconds
TestRunnerSetup               PASS      576.43 seconds
TestRunner_l2cap-tester       FAIL      29.41 seconds
TestRunner_iso-tester         FAIL      35.97 seconds
TestRunner_bnep-tester        PASS      6.38 seconds
TestRunner_mgmt-tester        FAIL      115.59 seconds
TestRunner_rfcomm-tester      PASS      9.66 seconds
TestRunner_sco-tester         FAIL      14.31 seconds
TestRunner_ioctl-tester       PASS      10.16 seconds
TestRunner_mesh-tester        FAIL      12.55 seconds
TestRunner_smp-tester         FAIL      11.03 seconds
TestRunner_userchan-tester    PASS      6.69 seconds
IncrementalBuild              PENDING   0.55 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: TestRunner_l2cap-tester - FAIL
Desc: Run l2cap-tester with test-runner
Output:
Total: 96, Passed: 94 (97.9%), Failed: 2, Not Run: 0

Failed Test Cases
L2CAP BR/EDR Server - Set PHY 1M                     Failed       0.123 seconds
L2CAP BR/EDR Server - Set PHY 2M                     Failed       0.122 seconds
##############################
Test: TestRunner_iso-tester - FAIL
Desc: Run iso-tester with test-runner
Output:
BUG: KASAN: slab-use-after-free in le_read_features_complete+0x7e/0x2b0
Total: 141, Passed: 141 (100.0%), Failed: 0, Not Run: 0
##############################
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       0.106 seconds
##############################
Test: TestRunner_sco-tester - FAIL
Desc: Run sco-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
BUG: sleeping function called from invalid context at net/core/sock.c:3782
Total: 30, Passed: 30 (100.0%), Failed: 0, Not Run: 0
##############################
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    2.738 seconds
Mesh - Send cancel - 2                               Timed out    1.999 seconds
##############################
Test: TestRunner_smp-tester - FAIL
Desc: Run smp-tester with test-runner
Output:
WARNING: net/bluetooth/hci_conn.c:567 at hci_conn_timeout+0x15a/0x190, CPU#0: kworker/u5:2/54
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth