================================================================== BUG: KASAN: use-after-free in strlen+0x79/0x90 lib/string.c:527 Read of size 1 at addr ffff8881ce7f1208 by task syz-executor.2/3952 CPU: 1 PID: 3952 Comm: syz-executor.2 Not tainted 5.5.0-rc2-syzkaller #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+0xef/0x16e lib/dump_stack.c:118 print_address_description.constprop.0+0x16/0x200 mm/kasan/report.c:374 __kasan_report.cold+0x37/0x7f mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:639 strlen+0x79/0x90 lib/string.c:527 strlen include/linux/string.h:302 [inline] str_to_user+0x27/0x90 drivers/input/evdev.c:783 evdev_do_ioctl drivers/input/evdev.c:1186 [inline] evdev_ioctl_handler+0x130a/0x19f0 drivers/input/evdev.c:1284 vfs_ioctl fs/ioctl.c:47 [inline] file_ioctl fs/ioctl.c:545 [inline] do_vfs_ioctl+0x90c/0x1420 fs/ioctl.c:732 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:749 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:754 do_syscall_64+0xb6/0x5c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a9e9 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd227b8ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a9e9 RDX: 0000000020000040 RSI: 0000000080404507 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd227b8b6d4 R13: 00000000004c2fc3 R14: 00000000004d85d8 R15: 00000000ffffffff Allocated by task 17: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:486 kmalloc include/linux/slab.h:556 [inline] kzalloc include/linux/slab.h:670 [inline] xpad_probe+0x24b/0x1b20 drivers/input/joystick/xpad.c:1717 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0x1480/0x1c20 drivers/base/core.c:2487 usb_set_configuration+0xe67/0x1740 drivers/usb/core/message.c:2023 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 really_probe+0x281/0x6d0 drivers/base/dd.c:548 driver_probe_device+0x104/0x210 drivers/base/dd.c:721 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x360 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0x1480/0x1c20 drivers/base/core.c:2487 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2537 hub_port_connect drivers/usb/core/hub.c:5184 [inline] hub_port_connect_change drivers/usb/core/hub.c:5324 [inline] port_event drivers/usb/core/hub.c:5470 [inline] hub_event+0x1e59/0x3860 drivers/usb/core/hub.c:5552 process_one_work+0x92b/0x1530 kernel/workqueue.c:2264 worker_thread+0x96/0xe20 kernel/workqueue.c:2410 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 3469: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:335 [inline] __kasan_slab_free+0x129/0x170 mm/kasan/common.c:474 slab_free_hook mm/slub.c:1425 [inline] slab_free_freelist_hook mm/slub.c:1458 [inline] slab_free mm/slub.c:3005 [inline] kfree+0xda/0x310 mm/slub.c:3957 xpad_disconnect+0x1cb/0x4a3 drivers/input/joystick/xpad.c:1865 usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423 __device_release_driver drivers/base/dd.c:1134 [inline] device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1165 bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:532 device_del+0x481/0xd30 drivers/base/core.c:2664 usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237 usb_disconnect+0x284/0x8d0 drivers/usb/core/hub.c:2200 hub_port_connect drivers/usb/core/hub.c:5035 [inline] hub_port_connect_change drivers/usb/core/hub.c:5324 [inline] port_event drivers/usb/core/hub.c:5470 [inline] hub_event+0x1753/0x3860 drivers/usb/core/hub.c:5552 process_one_work+0x92b/0x1530 kernel/workqueue.c:2264 worker_thread+0x96/0xe20 kernel/workqueue.c:2410 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8881ce7f1000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 520 bytes inside of 1024-byte region [ffff8881ce7f1000, ffff8881ce7f1400) The buggy address belongs to the page: page:ffffea000739fc00 refcount:1 mapcount:0 mapping:ffff8881da002280 index:0x0 compound_mapcount: 0 raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da002280 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ce7f1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ce7f1180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881ce7f1200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ce7f1280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ce7f1300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================