syzbot


KASAN: slab-use-after-free Read in l2cap_register_user

Status: upstream: reported on 2024/11/07 13:17
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+0fe7e1aad7c10418ca87@syzkaller.appspotmail.com
First crash: 53d, last: 6d07h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in l2cap_register_user 0 (1) 2024/11/07 13:17

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:172 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:667 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0x7fb/0xee0 kernel/locking/mutex.c:735
Read of size 8 at addr ffff888026c74060 by task syz.0.2104/12915

CPU: 0 UID: 0 PID: 12915 Comm: syz.0.2104 Not tainted 6.13.0-rc3-syzkaller-00672-gb73e56f16250 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
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
 __mutex_waiter_is_first kernel/locking/mutex.c:172 [inline]
 __mutex_lock_common kernel/locking/mutex.c:667 [inline]
 __mutex_lock+0x7fb/0xee0 kernel/locking/mutex.c:735
 l2cap_register_user+0x6d/0x1e0 net/bluetooth/l2cap_core.c:1696
 hidp_connection_add+0x144b/0x18c0 net/bluetooth/hidp/core.c:1378
 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:81 [inline]
 hidp_sock_ioctl+0x446/0x870 net/bluetooth/hidp/sock.c:128
 sock_do_ioctl+0x158/0x460 net/socket.c:1220
 sock_ioctl+0x626/0x8e0 net/socket.c:1339
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2aa8185d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2aa9005038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2aa8375fa0 RCX: 00007f2aa8185d29
RDX: 0000000020003900 RSI: 00000000400448c8 RDI: 0000000000000008
RBP: 00007f2aa8201aa8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2aa8375fa0 R15: 00007fff0d49a488
 </TASK>

Allocated by task 12803:
 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]
 __do_kmalloc_node mm/slub.c:4298 [inline]
 __kmalloc_noprof+0x285/0x4c0 mm/slub.c:4310
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 hci_alloc_dev_priv+0x27/0x2030 net/bluetooth/hci_core.c:2439
 hci_alloc_dev include/net/bluetooth/hci_core.h:1693 [inline]
 __vhci_create_device drivers/bluetooth/hci_vhci.c:399 [inline]
 vhci_create_device+0x116/0x6a0 drivers/bluetooth/hci_vhci.c:470
 vhci_get_user drivers/bluetooth/hci_vhci.c:527 [inline]
 vhci_write+0x3cf/0x490 drivers/bluetooth/hci_vhci.c:607
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xaeb/0xd30 fs/read_write.c:679
 ksys_write+0x18f/0x2b0 fs/read_write.c:731
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 12803:
 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
 hci_release_dev+0x1525/0x16b0 net/bluetooth/hci_core.c:2758
 bt_host_release+0x83/0x90 net/bluetooth/hci_sysfs.c:87
 device_release+0x99/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x22f/0x480 lib/kobject.c:737
 vhci_release+0x88/0xd0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x23c/0xa50 fs/file_table.c:450
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xa2f/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544
 insert_work+0x3e/0x330 kernel/workqueue.c:2183
 __queue_work+0xb66/0xf50 kernel/workqueue.c:2343
 queue_work_on+0x1c2/0x380 kernel/workqueue.c:2390
 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

Second to last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544
 insert_work+0x3e/0x330 kernel/workqueue.c:2183
 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2339
 call_timer_fn+0x187/0x650 kernel/time/timer.c:1793
 expire_timers kernel/time/timer.c:1839 [inline]
 __run_timers kernel/time/timer.c:2418 [inline]
 __run_timer_base+0x695/0x8e0 kernel/time/timer.c:2430
 run_timer_base kernel/time/timer.c:2439 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2449
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 do_softirq+0x11b/0x1e0 kernel/softirq.c:462
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 netif_addr_unlock_bh include/linux/netdevice.h:4655 [inline]
 dev_uc_add+0xd2/0x110 net/core/dev_addr_lists.c:693
 vlan_dev_set_mac_address+0x1a5/0x3f0 net/8021q/vlan_dev.c:344
 dev_set_mac_address+0x327/0x510 net/core/dev.c:9207
 dev_set_mac_address_user+0x31/0x50 net/core/dev.c:9226
 do_setlink+0x74b/0x4210 net/core/rtnetlink.c:3064
 rtnl_changelink net/core/rtnetlink.c:3723 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3875 [inline]
 rtnl_newlink+0x1bb6/0x2210 net/core/rtnetlink.c:4012
 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6902
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:726
 __sys_sendto+0x363/0x4c0 net/socket.c:2208
 __do_sys_sendto net/socket.c:2215 [inline]
 __se_sys_sendto net/socket.c:2211 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2211
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888026c74000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 96 bytes inside of
 freed 8192-byte region [ffff888026c74000, ffff888026c76000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26c70
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801ac42280 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000020002 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff88801ac42280 0000000000000000 dead000000000001
head: 0000000000000000 0000000000020002 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea00009b1c01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 11200, tgid 11199 (syz.4.1526), ts 222773049387, free_ts 222748815452
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269
 alloc_slab_page+0x6a/0x110 mm/slub.c:2423
 allocate_slab+0x5a/0x2b0 mm/slub.c:2589
 new_slab mm/slub.c:2642 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830
 __slab_alloc+0x58/0xa0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4324
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 mr_table_alloc+0x65/0x260 net/ipv4/ipmr_base.c:41
 ipmr_new_table net/ipv4/ipmr.c:432 [inline]
 ipmr_rules_init net/ipv4/ipmr.c:266 [inline]
 ipmr_net_init+0x219/0x390 net/ipv4/ipmr.c:3116
 ops_init+0x31e/0x590 net/core/net_namespace.c:138
 setup_net+0x287/0x9e0 net/core/net_namespace.c:362
 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:516
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
page last free pid 5500 tgid 5500 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2657
 __slab_free+0x2c2/0x380 mm/slub.c:4524
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4220
 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1331 [inline]
 nlmsg_new include/net/netlink.h:1018 [inline]
 netlink_ack+0x145/0xa50 net/netlink/af_netlink.c:2480
 netlink_rcv_skb+0x262/0x430 net/netlink/af_netlink.c:2549
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:726
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2594
 ___sys_sendmsg net/socket.c:2648 [inline]
 __sys_sendmsg+0x269/0x350 net/socket.c:2680
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83

Memory state around the buggy address:
 ffff888026c73f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888026c73f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888026c74000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff888026c74080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888026c74100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/20 06:49 net-next b73e56f16250 1d58202c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in l2cap_register_user
2024/11/03 12:48 net-next dbb9a7ef3478 f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in l2cap_register_user
* Struck through repros no longer work on HEAD.