Hello, When fuzzing the Linux kernel driver v6.0-rc6, the following crash was triggered. HEAD commit: 521a547ced6477c54b4b0cc206000406c221b4d6 git tree: upstream kernel config: https://pastebin.com/raw/hekxU61F console output: https://pastebin.com/raw/gvADdA0t Sorry for failing to extract the reproducer. But on other versions of Linux, I also triggered this crash. I would appreciate it if you have any idea how to solve this bug. The crash report is as follows: ================================================================== BUG: KASAN: use-after-free in keyspan_close+0x240/0x260 drivers/usb/serial/keyspan.c:1589 Write of size 4 at addr ffff88805a1e7104 by task syz-executor.5/27414 CPU: 1 PID: 27414 Comm: syz-executor.5 Not tainted 6.0.0-rc4+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0xe5/0x66d mm/kasan/report.c:433 kasan_report+0x8a/0x1b0 mm/kasan/report.c:495 keyspan_close+0x240/0x260 drivers/usb/serial/keyspan.c:1589 serial_port_shutdown+0x89/0x110 drivers/usb/serial/usb-serial.c:309 tty_port_shutdown+0x1ec/0x270 drivers/tty/tty_port.c:379 tty_port_hangup+0x103/0x170 drivers/tty/tty_port.c:407 __tty_hangup.part.0+0x65b/0x770 drivers/tty/tty_io.c:660 __tty_hangup drivers/tty/tty_io.c:592 [inline] tty_vhangup drivers/tty/tty_io.c:707 [inline] tty_ioctl+0x956/0x1430 drivers/tty/tty_io.c:2718 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff1e4ca80fd Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff1e5421bf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff1e4d9c4e0 RCX: 00007ff1e4ca80fd RDX: 0000000000000000 RSI: 0000000000005437 RDI: 0000000000000003 RBP: 00007ff1e4d0b606 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffcf5e0c9f R14: 00007fffcf5e0e40 R15: 00007ff1e5421d80 </TASK> Allocated by task 9889: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kasan_kmalloc include/linux/kasan.h:234 [inline] kmem_cache_alloc_trace+0x19b/0x380 mm/slub.c:3284 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] keyspan_port_probe+0xbe/0xe40 drivers/usb/serial/keyspan.c:2886 usb_serial_device_probe+0xfe/0x3d0 drivers/usb/serial/bus.c:47 call_driver_probe drivers/base/dd.c:560 [inline] really_probe+0x249/0xa90 drivers/base/dd.c:639 __driver_probe_device+0x1df/0x4d0 drivers/base/dd.c:778 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:808 __device_attach_driver+0x1da/0x2d0 drivers/base/dd.c:936 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427 __device_attach+0x283/0x480 drivers/base/dd.c:1008 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487 device_add+0xc96/0x1da0 drivers/base/core.c:3517 usb_serial_probe.cold+0x163f/0x291e drivers/usb/serial/usb-serial.c:1152 usb_probe_interface+0x361/0x800 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:560 [inline] really_probe+0x249/0xa90 drivers/base/dd.c:639 __driver_probe_device+0x1df/0x4d0 drivers/base/dd.c:778 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:808 __device_attach_driver+0x1da/0x2d0 drivers/base/dd.c:936 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427 __device_attach+0x283/0x480 drivers/base/dd.c:1008 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487 device_add+0xc96/0x1da0 drivers/base/core.c:3517 usb_set_configuration+0x1014/0x1900 drivers/usb/core/message.c:2170 usb_generic_driver_probe+0x9d/0xe0 drivers/usb/core/generic.c:238 usb_probe_device+0xd4/0x2a0 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:560 [inline] really_probe+0x249/0xa90 drivers/base/dd.c:639 __driver_probe_device+0x1df/0x4d0 drivers/base/dd.c:778 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:808 __device_attach_driver+0x1da/0x2d0 drivers/base/dd.c:936 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427 __device_attach+0x283/0x480 drivers/base/dd.c:1008 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487 device_add+0xc96/0x1da0 drivers/base/core.c:3517 usb_new_device.cold+0x69d/0x10ef drivers/usb/core/hub.c:2573 hub_port_connect drivers/usb/core/hub.c:5353 [inline] hub_port_connect_change drivers/usb/core/hub.c:5497 [inline] port_event drivers/usb/core/hub.c:5653 [inline] hub_event+0x23bd/0x4260 drivers/usb/core/hub.c:5735 process_one_work+0x9c7/0x1650 kernel/workqueue.c:2289 worker_thread+0x623/0x1070 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Freed by task 9889: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free mm/kasan/common.c:329 [inline] __kasan_slab_free+0x11d/0x1b0 mm/kasan/common.c:375 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook mm/slub.c:1780 [inline] slab_free mm/slub.c:3534 [inline] kfree+0xe9/0x650 mm/slub.c:4562 usb_serial_device_remove+0x13f/0x1a0 drivers/usb/serial/bus.c:97 device_remove+0xc8/0x170 drivers/base/dd.c:548 __device_release_driver drivers/base/dd.c:1249 [inline] device_release_driver_internal+0x1a7/0x360 drivers/base/dd.c:1275 bus_remove_device+0x2e3/0x590 drivers/base/bus.c:529 device_del+0x5d2/0xe80 drivers/base/core.c:3704 usb_serial_disconnect+0x23e/0x3b0 drivers/usb/serial/usb-serial.c:1205 usb_unbind_interface+0x1bd/0x890 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:550 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:542 __device_release_driver drivers/base/dd.c:1249 [inline] device_release_driver_internal+0x1a7/0x360 drivers/base/dd.c:1275 bus_remove_device+0x2e3/0x590 drivers/base/bus.c:529 device_del+0x5d2/0xe80 drivers/base/core.c:3704 usb_disable_device+0x214/0x600 drivers/usb/core/message.c:1419 usb_disconnect+0x285/0x860 drivers/usb/core/hub.c:2235 hub_port_connect drivers/usb/core/hub.c:5197 [inline] hub_port_connect_change drivers/usb/core/hub.c:5497 [inline] port_event drivers/usb/core/hub.c:5653 [inline] hub_event+0x1c1b/0x4260 drivers/usb/core/hub.c:5735 process_one_work+0x9c7/0x1650 kernel/workqueue.c:2289 worker_thread+0x623/0x1070 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x4a/0x390 kernel/workqueue.c:1358 __queue_work+0x4d4/0x1200 kernel/workqueue.c:1517 queue_work_on+0xee/0x110 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:503 [inline] call_usermodehelper_exec+0x1cc/0x490 kernel/umh.c:435 kobject_uevent_env+0xf14/0x1640 lib/kobject_uevent.c:618 kset_register+0x49/0x60 lib/kobject.c:849 __class_register+0x20b/0x4a0 drivers/base/class.c:188 __class_create+0xca/0x140 drivers/base/class.c:242 ghid_setup+0x71/0x150 drivers/usb/gadget/function/f_hid.c:1322 hidg_alloc_inst+0x179/0x250 drivers/usb/gadget/function/f_hid.c:1217 try_get_usb_function_instance+0x122/0x1e0 drivers/usb/gadget/functions.c:28 usb_get_function_instance+0x13/0xa0 drivers/usb/gadget/functions.c:44 function_make+0x105/0x3e0 drivers/usb/gadget/configfs.c:617 configfs_mkdir+0x46a/0xb90 fs/configfs/dir.c:1327 vfs_mkdir+0x69f/0xa30 fs/namei.c:4013 do_mkdirat+0x249/0x2c0 fs/namei.c:4038 __do_sys_mkdir fs/namei.c:4058 [inline] __se_sys_mkdir fs/namei.c:4056 [inline] __x64_sys_mkdir+0x61/0x80 fs/namei.c:4056 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 insert_work+0x4a/0x390 kernel/workqueue.c:1358 __queue_work+0x4d4/0x1200 kernel/workqueue.c:1517 queue_work_on+0xee/0x110 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:503 [inline] call_usermodehelper_exec+0x1cc/0x490 kernel/umh.c:435 kobject_uevent_env+0xf14/0x1640 lib/kobject_uevent.c:618 netdev_queue_add_kobject net/core/net-sysfs.c:1677 [inline] netdev_queue_update_kobjects+0x3ba/0x4d0 net/core/net-sysfs.c:1718 register_queue_kobjects net/core/net-sysfs.c:1779 [inline] netdev_register_kobject+0x333/0x400 net/core/net-sysfs.c:2019 register_netdevice+0xbe9/0x1370 net/core/dev.c:10070 __ip_tunnel_create+0x398/0x580 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x32c/0xa40 net/ipv4/ip_tunnel.c:1073 ops_init+0xaf/0x420 net/core/net_namespace.c:135 setup_net+0x415/0xa40 net/core/net_namespace.c:326 copy_net_ns+0x2d9/0x660 net/core/net_namespace.c:472 create_new_namespaces.isra.0+0x3cb/0xae0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc8/0x1f0 kernel/nsproxy.c:227 ksys_unshare+0x450/0x920 kernel/fork.c:3183 __do_sys_unshare kernel/fork.c:3254 [inline] __se_sys_unshare kernel/fork.c:3252 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3252 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0x80 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88805a1e7100 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 4 bytes inside of 192-byte region [ffff88805a1e7100, ffff88805a1e71c0) The buggy address belongs to the physical page: page:ffffea00016879c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a1e7 flags: 0x4fff00000000200(slab|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000000200 0000000000000000 dead000000000001 ffff888011c41a00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 6450, tgid 6450 (syz-executor.1), ts 146447587150, free_ts 146293511182 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2525 [inline] prep_new_page+0x2c6/0x350 mm/page_alloc.c:2532 get_page_from_freelist+0xae9/0x3a80 mm/page_alloc.c:4283 __alloc_pages+0x321/0x710 mm/page_alloc.c:5515 alloc_pages+0x117/0x2f0 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab mm/slub.c:1969 [inline] new_slab+0x246/0x3a0 mm/slub.c:2029 ___slab_alloc+0xa50/0x1060 mm/slub.c:3031 __slab_alloc.isra.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] slab_alloc mm/slub.c:3251 [inline] kmem_cache_alloc_trace+0x35b/0x380 mm/slub.c:3282 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] call_usermodehelper_setup+0x97/0x340 kernel/umh.c:365 kobject_uevent_env+0xef5/0x1640 lib/kobject_uevent.c:614 netdev_queue_add_kobject net/core/net-sysfs.c:1677 [inline] netdev_queue_update_kobjects+0x3ba/0x4d0 net/core/net-sysfs.c:1718 register_queue_kobjects net/core/net-sysfs.c:1779 [inline] netdev_register_kobject+0x333/0x400 net/core/net-sysfs.c:2019 register_netdevice+0xbe9/0x1370 net/core/dev.c:10070 veth_newlink+0x4d6/0x9a0 drivers/net/veth.c:1795 rtnl_newlink_create net/core/rtnetlink.c:3363 [inline] __rtnl_newlink+0xfbc/0x16f0 net/core/rtnetlink.c:3580 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3593 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5ab/0xd00 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x410 mm/page_alloc.c:3476 __vunmap+0x6ff/0xaa0 mm/vmalloc.c:2696 free_work+0x58/0x70 mm/vmalloc.c:97 process_one_work+0x9c7/0x1650 kernel/workqueue.c:2289 worker_thread+0x623/0x1070 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Memory state around the buggy address: ffff88805a1e7000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805a1e7080: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805a1e7100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a1e7180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88805a1e7200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================
