| Message ID | 20250117155608.3836950-1-luiz.dentz@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd | expand |
| Context | Check | Description |
|---|---|---|
| tedd_an/pre-ci_am | success | Success |
| tedd_an/SubjectPrefix | success | Gitlint PASS |
| tedd_an/BuildKernel | success | BuildKernel PASS |
| tedd_an/CheckAllWarning | success | CheckAllWarning PASS |
| tedd_an/CheckSparse | success | CheckSparse PASS |
| tedd_an/BuildKernel32 | success | BuildKernel32 PASS |
| tedd_an/TestRunnerSetup | success | TestRunnerSetup PASS |
| tedd_an/TestRunner_l2cap-tester | success | TestRunner PASS |
| tedd_an/TestRunner_iso-tester | success | TestRunner PASS |
| tedd_an/TestRunner_bnep-tester | success | TestRunner PASS |
| tedd_an/TestRunner_mgmt-tester | fail | TestRunner_mgmt-tester: Total: 490, Passed: 485 (99.0%), Failed: 1, Not Run: 4 |
| tedd_an/TestRunner_rfcomm-tester | success | TestRunner PASS |
| tedd_an/TestRunner_sco-tester | success | TestRunner PASS |
| tedd_an/TestRunner_ioctl-tester | success | TestRunner PASS |
| tedd_an/TestRunner_mesh-tester | success | TestRunner PASS |
| tedd_an/TestRunner_smp-tester | success | TestRunner PASS |
| tedd_an/TestRunner_userchan-tester | success | TestRunner PASS |
#syz test On Fri, Jan 17, 2025 at 10:56 AM Luiz Augusto von Dentz <luiz.dentz@gmail.com> wrote: > > From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> > > After the hci sync command releases l2cap_conn, the hci receive data work > queue references the released l2cap_conn when sending to the upper layer. > Add hci dev lock to the hci receive data work queue to synchronize the two. > > [1] > BUG: KASAN: slab-use-after-free in l2cap_send_cmd+0x187/0x8d0 net/bluetooth/l2cap_core.c:954 > Read of size 8 at addr ffff8880271a4000 by task kworker/u9:2/5837 > > CPU: 0 UID: 0 PID: 5837 Comm: kworker/u9:2 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 > Workqueue: hci1 hci_rx_work > Call Trace: > <TASK> > __dump_stack lib/dump_stack.c:94 [inline] > dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 > print_address_description mm/kasan/report.c:378 [inline] > print_report+0x169/0x550 mm/kasan/report.c:489 > kasan_report+0x143/0x180 mm/kasan/report.c:602 > l2cap_build_cmd net/bluetooth/l2cap_core.c:2964 [inline] > l2cap_send_cmd+0x187/0x8d0 net/bluetooth/l2cap_core.c:954 > l2cap_sig_send_rej net/bluetooth/l2cap_core.c:5502 [inline] > l2cap_sig_channel net/bluetooth/l2cap_core.c:5538 [inline] > l2cap_recv_frame+0x221f/0x10db0 net/bluetooth/l2cap_core.c:6817 > hci_acldata_packet net/bluetooth/hci_core.c:3797 [inline] > hci_rx_work+0x508/0xdb0 net/bluetooth/hci_core.c:4040 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 > worker_thread+0x870/0xd30 kernel/workqueue.c:3391 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > </TASK> > > Allocated by task 5837: > kasan_save_stack mm/kasan/common.c:47 [inline] > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > poison_kmalloc_redzone mm/kasan/common.c:377 [inline] > __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 > kasan_kmalloc include/linux/kasan.h:260 [inline] > __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 > kmalloc_noprof include/linux/slab.h:901 [inline] > kzalloc_noprof include/linux/slab.h:1037 [inline] > l2cap_conn_add+0xa9/0x8e0 net/bluetooth/l2cap_core.c:6860 > l2cap_connect_cfm+0x115/0x1090 net/bluetooth/l2cap_core.c:7239 > hci_connect_cfm include/net/bluetooth/hci_core.h:2057 [inline] > hci_remote_features_evt+0x68e/0xac0 net/bluetooth/hci_event.c:3726 > hci_event_func net/bluetooth/hci_event.c:7473 [inline] > hci_event_packet+0xac2/0x1540 net/bluetooth/hci_event.c:7525 > hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4035 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 > worker_thread+0x870/0xd30 kernel/workqueue.c:3391 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Freed by task 54: > kasan_save_stack mm/kasan/common.c:47 [inline] > kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 > kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 > poison_slab_object mm/kasan/common.c:247 [inline] > __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 > kasan_slab_free include/linux/kasan.h:233 [inline] > slab_free_hook mm/slub.c:2353 [inline] > slab_free mm/slub.c:4613 [inline] > kfree+0x196/0x430 mm/slub.c:4761 > l2cap_connect_cfm+0xcc/0x1090 net/bluetooth/l2cap_core.c:7235 > hci_connect_cfm include/net/bluetooth/hci_core.h:2057 [inline] > hci_conn_failed+0x287/0x400 net/bluetooth/hci_conn.c:1266 > hci_abort_conn_sync+0x56c/0x11f0 net/bluetooth/hci_sync.c:5603 > hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:332 > process_one_work kernel/workqueue.c:3229 [inline] > process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 > worker_thread+0x870/0xd30 kernel/workqueue.c:3391 > kthread+0x2f0/0x390 kernel/kthread.c:389 > ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > Reported-by: syzbot+31c2f641b850a348a734@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=31c2f641b850a348a734 > Tested-by: syzbot+31c2f641b850a348a734@syzkaller.appspotmail.com > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> > --- > net/bluetooth/l2cap_core.c | 38 ++++++++++++++++++++++++++++++++++++-- > 1 file changed, 36 insertions(+), 2 deletions(-) > > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c > index 27b4c4a2ba1f..025bb038e304 100644 > --- a/net/bluetooth/l2cap_core.c > +++ b/net/bluetooth/l2cap_core.c > @@ -951,11 +951,18 @@ static u8 l2cap_get_ident(struct l2cap_conn *conn) > static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len, > void *data) > { > - struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data); > + struct sk_buff *skb; > u8 flags; > > + /* Check if HCI_CONN_DROP has been set since it means hci_chan_del has > + * been called. > + */ > + if (test_bit(HCI_CONN_DROP, &conn->hcon->flags)) > + return; > + > BT_DBG("code 0x%2.2x", code); > > + skb = l2cap_build_cmd(conn, code, ident, len, data); > if (!skb) > return; > > @@ -6785,6 +6792,12 @@ static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb) > u16 cid, len; > __le16 psm; > > + /* Check if hcon has been dropped then drop its packets as well */ > + if (test_bit(HCI_CONN_DROP, &hcon->flags)) { > + kfree_skb(skb); > + return; > + } > + > if (hcon->state != BT_CONNECTED) { > BT_DBG("queueing pending rx skb"); > skb_queue_tail(&conn->pending_rx, skb); > @@ -7466,14 +7479,33 @@ static void l2cap_recv_reset(struct l2cap_conn *conn) > conn->rx_len = 0; > } > > +static struct l2cap_conn *l2cap_conn_hold_unless_zero(struct l2cap_conn *c) > +{ > + BT_DBG("conn %p orig refcnt %u", c, kref_read(&c->ref)); > + > + if (!kref_get_unless_zero(&c->ref)) > + return NULL; > + > + return c; > +} > + > void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) > { > - struct l2cap_conn *conn = hcon->l2cap_data; > + struct l2cap_conn *conn; > int len; > > + /* Lock hdev to access l2cap_data to avoid race with l2cap_conn_del */ > + hci_dev_lock(hcon->hdev); > + > + conn = hcon->l2cap_data; > + > if (!conn) > conn = l2cap_conn_add(hcon); > > + conn = l2cap_conn_hold_unless_zero(conn); > + > + hci_dev_unlock(hcon->hdev); > + > if (!conn) > goto drop; > > @@ -7565,6 +7597,8 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) > break; > } > > + l2cap_conn_put(conn); > + > drop: > kfree_skb(skb); > } > -- > 2.47.1 >
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=926497 ---Test result--- Test Summary: CheckPatch PENDING 0.34 seconds GitLint PENDING 0.42 seconds SubjectPrefix PASS 0.05 seconds BuildKernel PASS 24.55 seconds CheckAllWarning PASS 26.77 seconds CheckSparse PASS 30.58 seconds BuildKernel32 PASS 24.28 seconds TestRunnerSetup PASS 434.16 seconds TestRunner_l2cap-tester PASS 20.91 seconds TestRunner_iso-tester PASS 34.65 seconds TestRunner_bnep-tester PASS 4.90 seconds TestRunner_mgmt-tester FAIL 122.82 seconds TestRunner_rfcomm-tester PASS 7.65 seconds TestRunner_sco-tester PASS 9.50 seconds TestRunner_ioctl-tester PASS 8.31 seconds TestRunner_mesh-tester PASS 6.14 seconds TestRunner_smp-tester PASS 7.08 seconds TestRunner_userchan-tester PASS 5.08 seconds IncrementalBuild PENDING 0.77 seconds Details ############################## Test: CheckPatch - PENDING Desc: Run checkpatch.pl script Output: ############################## Test: GitLint - PENDING Desc: Run gitlint Output: ############################## Test: TestRunner_mgmt-tester - FAIL Desc: Run mgmt-tester with test-runner Output: Total: 490, Passed: 485 (99.0%), Failed: 1, Not Run: 4 Failed Test Cases LL Privacy - Set Flags 3 (2 Devices to RL) Failed 0.204 seconds ############################## Test: IncrementalBuild - PENDING Desc: Incremental build with the patches in the series Output: --- Regards, Linux Bluetooth
Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: general protection fault in l2cap_send_cmd Bluetooth: Wrong link type (-22) Oops: general protection fault, probably for non-canonical address 0xdffffc0000000064: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000320-0x0000000000000327] CPU: 0 UID: 0 PID: 8403 Comm: kworker/u9:10 Not tainted 6.13.0-rc7-syzkaller-g9bffa1ad25b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: hci4 hci_rx_work RIP: 0010:l2cap_send_cmd+0x563/0x8d0 net/bluetooth/l2cap_core.c:964 Code: fc ff df 80 3c 08 00 74 08 48 89 df e8 f6 54 42 f7 bd 22 03 00 00 48 03 2b 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 11 01 00 00 0f b6 5d 00 89 de 83 e6 40 31 RSP: 0018:ffffc9000557f378 EFLAGS: 00010202 RAX: 0000000000000064 RBX: ffff88801eb23c78 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888034724000 RBP: 0000000000000322 R08: ffffffff8ac395c4 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed100f588363 R12: ffff888034724000 R13: ffff888034724010 R14: ffff88801eb22c80 R15: ffff888063932140 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558b7da5c8 CR3: 000000002974a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> l2cap_sig_send_rej net/bluetooth/l2cap_core.c:5502 [inline] l2cap_sig_channel net/bluetooth/l2cap_core.c:5538 [inline] l2cap_recv_frame+0x221f/0x10db0 net/bluetooth/l2cap_core.c:6817 hci_acldata_packet net/bluetooth/hci_core.c:3797 [inline] hci_rx_work+0x508/0xdb0 net/bluetooth/hci_core.c:4040 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:l2cap_send_cmd+0x563/0x8d0 net/bluetooth/l2cap_core.c:964 Code: fc ff df 80 3c 08 00 74 08 48 89 df e8 f6 54 42 f7 bd 22 03 00 00 48 03 2b 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 11 01 00 00 0f b6 5d 00 89 de 83 e6 40 31 RSP: 0018:ffffc9000557f378 EFLAGS: 00010202 RAX: 0000000000000064 RBX: ffff88801eb23c78 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888034724000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: df 80 3c 08 00 74 filds 0x7400083c(%rax) 6: 08 48 89 or %cl,-0x77(%rax) 9: df e8 fucomip %st(0),%st b: f6 54 42 f7 notb -0x9(%rdx,%rax,2) f: bd 22 03 00 00 mov $0x322,%ebp 14: 48 03 2b add (%rbx),%rbp 17: 48 89 e8 mov %rbp,%rax 1a: 48 c1 e8 03 shr $0x3,%rax 1e: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 25: fc ff df * 28: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax <-- trapping instruction 2c: 84 c0 test %al,%al 2e: 0f 85 11 01 00 00 jne 0x145 34: 0f b6 5d 00 movzbl 0x0(%rbp),%ebx 38: 89 de mov %ebx,%esi 3a: 83 e6 40 and $0x40,%esi 3d: 31 .byte 0x31 Tested on: commit: 9bffa1ad Merge tag 'drm-fixes-2025-01-17' of https://g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16139fc4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=aadf89e2f6db86cc dashboard link: https://syzkaller.appspot.com/bug?extid=31c2f641b850a348a734 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Note: no patches were applied.
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 27b4c4a2ba1f..025bb038e304 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -951,11 +951,18 @@ static u8 l2cap_get_ident(struct l2cap_conn *conn) static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len, void *data) { - struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data); + struct sk_buff *skb; u8 flags; + /* Check if HCI_CONN_DROP has been set since it means hci_chan_del has + * been called. + */ + if (test_bit(HCI_CONN_DROP, &conn->hcon->flags)) + return; + BT_DBG("code 0x%2.2x", code); + skb = l2cap_build_cmd(conn, code, ident, len, data); if (!skb) return; @@ -6785,6 +6792,12 @@ static void l2cap_recv_frame(struct l2cap_conn *conn, struct sk_buff *skb) u16 cid, len; __le16 psm; + /* Check if hcon has been dropped then drop its packets as well */ + if (test_bit(HCI_CONN_DROP, &hcon->flags)) { + kfree_skb(skb); + return; + } + if (hcon->state != BT_CONNECTED) { BT_DBG("queueing pending rx skb"); skb_queue_tail(&conn->pending_rx, skb); @@ -7466,14 +7479,33 @@ static void l2cap_recv_reset(struct l2cap_conn *conn) conn->rx_len = 0; } +static struct l2cap_conn *l2cap_conn_hold_unless_zero(struct l2cap_conn *c) +{ + BT_DBG("conn %p orig refcnt %u", c, kref_read(&c->ref)); + + if (!kref_get_unless_zero(&c->ref)) + return NULL; + + return c; +} + void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) { - struct l2cap_conn *conn = hcon->l2cap_data; + struct l2cap_conn *conn; int len; + /* Lock hdev to access l2cap_data to avoid race with l2cap_conn_del */ + hci_dev_lock(hcon->hdev); + + conn = hcon->l2cap_data; + if (!conn) conn = l2cap_conn_add(hcon); + conn = l2cap_conn_hold_unless_zero(conn); + + hci_dev_unlock(hcon->hdev); + if (!conn) goto drop; @@ -7565,6 +7597,8 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) break; } + l2cap_conn_put(conn); + drop: kfree_skb(skb); }