syzbot


KASAN: use-after-free Read in j1939_xtp_rx_abort_one

Status: fixed on 2020/01/18 22:47
Subsystems: can
[Documentation on labels]
Reported-by: syzbot+db4869ba599c0de9b13e@syzkaller.appspotmail.com
Fix commit: ddeeb7d4822e can: j1939: j1939_can_recv(): add priv refcounting
First crash: 1633d, last: 1625d
Cause bisection: introduced by (bisect log) :
commit 9d71dd0c70099914fcd063135da3c580865e924c
Author: The j1939 authors <linux-can@vger.kernel.org>
Date: Mon Oct 8 09:48:36 2018 +0000

  can: add support of SAE J1939 protocol

Crash: general protection fault in j1939_sk_sendmsg (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit ddeeb7d4822ed06d79fc15e822b70dce3fa77e39
Author: Oleksij Rempel <o.rempel@pengutronix.de>
Date: Sat Nov 9 15:11:18 2019 +0000

  can: j1939: j1939_can_recv(): add priv refcounting

  
Discussions (2)
Title Replies (including bot) Last reply
KASAN: use-after-free Read in j1939_xtp_rx_abort_one 0 (4) 2020/01/13 16:42
[PATCH v1 0/9] can: j1939: fix multiple issues found by syzbot 16 (16) 2019/11/13 10:04

Sample crash report:
vcan0: j1939_tp_rxtimer: 0x000000000377fab2: rx timeout, send abort
vcan0: j1939_xtp_rx_abort_one: 0x000000000377fab2: 0x00000: (3) A timeout occurred and this is the connection abort to close the session.
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x96/0x1be0 kernel/locking/lockdep.c:3828
Read of size 8 at addr ffff888096d4d080 by task ksoftirqd/1/16

CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 __lock_acquire+0x96/0x1be0 kernel/locking/lockdep.c:3828
 lock_acquire+0x158/0x250 kernel/locking/lockdep.c:4487
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x34/0x50 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:343 [inline]
 j1939_session_list_lock net/can/j1939/transport.c:238 [inline]
 j1939_session_get_by_addr net/can/j1939/transport.c:530 [inline]
 j1939_xtp_rx_abort_one+0x89/0x3f0 net/can/j1939/transport.c:1242
 j1939_xtp_rx_abort net/can/j1939/transport.c:1270 [inline]
 j1939_tp_cmd_recv net/can/j1939/transport.c:1958 [inline]
 j1939_tp_recv+0x648/0xb80 net/can/j1939/transport.c:1991
 j1939_can_recv+0x424/0x650 net/can/j1939/main.c:100
 deliver net/can/af_can.c:568 [inline]
 can_rcv_filter+0x3c0/0x8b0 net/can/af_can.c:602
 can_receive+0x2ac/0x3b0 net/can/af_can.c:659
 can_rcv+0xe4/0x220 net/can/af_can.c:685
 __netif_receive_skb_one_core net/core/dev.c:4929 [inline]
 __netif_receive_skb+0x136/0x370 net/core/dev.c:5043
 process_backlog+0x4d8/0x930 net/core/dev.c:5874
 napi_poll net/core/dev.c:6311 [inline]
 net_rx_action+0x5ef/0x10d0 net/core/dev.c:6379
 __do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:766
 run_ksoftirqd+0x64/0xf0 kernel/softirq.c:603
 smpboot_thread_fn+0x5b3/0x9a0 kernel/smpboot.c:165
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 7912:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524
 kmem_cache_alloc_trace+0x221/0x2f0 mm/slab.c:3550
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:690 [inline]
 j1939_priv_create net/can/j1939/main.c:122 [inline]
 j1939_netdev_start+0x177/0x730 net/can/j1939/main.c:251
 j1939_sk_bind+0x2c0/0xac0 net/can/j1939/socket.c:438
 __sys_bind+0x2c2/0x3a0 net/socket.c:1647
 __do_sys_bind net/socket.c:1658 [inline]
 __se_sys_bind net/socket.c:1656 [inline]
 __x64_sys_bind+0x7a/0x90 net/socket.c:1656
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 7912:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x115/0x200 mm/slab.c:3756
 __j1939_priv_release net/can/j1939/main.c:154 [inline]
 kref_put include/linux/kref.h:65 [inline]
 j1939_priv_put net/can/j1939/main.c:159 [inline]
 j1939_netdev_stop+0x20c/0x230 net/can/j1939/main.c:291
 j1939_sk_release+0x61f/0x810 net/can/j1939/socket.c:580
 __sock_release net/socket.c:590 [inline]
 sock_close+0xe1/0x260 net/socket.c:1268
 __fput+0x2e4/0x740 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:313
 task_work_run+0x17e/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
 prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274
 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888096d4c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4224 bytes inside of
 8192-byte region [ffff888096d4c000, ffff888096d4e000)
The buggy address belongs to the page:
page:ffffea00025b5300 refcount:1 mapcount:0 mapping:ffff8880aa4021c0 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea0002505708 ffffea0002764608 ffff8880aa4021c0
raw: 0000000000000000 ffff888096d4c000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888096d4cf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888096d4d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888096d4d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888096d4d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888096d4d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/11/12 14:44 upstream de620fb99ef2 048f2d49 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/11/09 05:20 upstream 6737e7634951 dc438b91 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/11/07 15:43 upstream 4dd58158254c d797d201 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/11/07 15:16 upstream 4dd58158254c d797d201 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/11/07 12:04 upstream 4dd58158254c d797d201 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/11/05 21:29 upstream a99d8080aaf3 0f3ec414 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/11/11 14:29 upstream 9805a68371ce dc438b91 .config console log report syz ci-upstream-kasan-gce-smack-root
2019/11/08 23:48 upstream 6737e7634951 dc438b91 .config console log report ci-upstream-kasan-gce-smack-root
2019/11/07 22:49 upstream 847120f859cc f39aff9e .config console log report ci-upstream-kasan-gce-smack-root
2019/11/05 19:16 upstream a99d8080aaf3 0f3ec414 .config console log report ci-upstream-kasan-gce-smack-root
2019/11/05 02:53 upstream a99d8080aaf3 76630fc9 .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.