================================================================== BUG: KASAN: use-after-free in strlen+0x79/0x90 lib/string.c:527 Read of size 1 at addr ffff8881cc4d9208 by task syz-executor.1/30433 CPU: 0 PID: 30433 Comm: syz-executor.1 Not tainted 5.5.0-rc7-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.cold+0xd3/0x314 mm/kasan/report.c:374 __kasan_report.cold+0x37/0x85 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+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b349 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:00007f0239954c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f02399556d4 RCX: 000000000045b349 RDX: 0000000020000cc0 RSI: 0000000080404507 RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002c6 R14: 00000000004c3c7c R15: 000000000075bfd4 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+0x310/0x800 drivers/usb/core/driver.c:361 really_probe+0x290/0xad0 drivers/base/dd.c:548 driver_probe_device+0x223/0x350 drivers/base/dd.c:721 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x390 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0x1459/0x1bf0 drivers/base/core.c:2487 usb_set_configuration+0xe47/0x17d0 drivers/usb/core/message.c:2023 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 usb_probe_device+0xaf/0x140 drivers/usb/core/driver.c:266 really_probe+0x290/0xad0 drivers/base/dd.c:548 driver_probe_device+0x223/0x350 drivers/base/dd.c:721 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:828 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 __device_attach+0x217/0x390 drivers/base/dd.c:894 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 device_add+0x1459/0x1bf0 drivers/base/core.c:2487 usb_new_device.cold+0x540/0xcd0 drivers/usb/core/hub.c:2538 hub_port_connect drivers/usb/core/hub.c:5185 [inline] hub_port_connect_change drivers/usb/core/hub.c:5325 [inline] port_event drivers/usb/core/hub.c:5471 [inline] hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5553 process_one_work+0x945/0x15c0 kernel/workqueue.c:2264 process_scheduled_works kernel/workqueue.c:2326 [inline] worker_thread+0x7ab/0xe20 kernel/workqueue.c:2412 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 21537: 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+0x117/0x160 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+0xd5/0x300 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+0x2eb/0x5a0 drivers/base/bus.c:532 device_del+0x481/0xd30 drivers/base/core.c:2664 usb_disable_device+0x23d/0x790 drivers/usb/core/message.c:1237 usb_disconnect+0x293/0x900 drivers/usb/core/hub.c:2201 hub_port_connect drivers/usb/core/hub.c:5036 [inline] hub_port_connect_change drivers/usb/core/hub.c:5325 [inline] port_event drivers/usb/core/hub.c:5471 [inline] hub_event+0x1a1d/0x4300 drivers/usb/core/hub.c:5553 process_one_work+0x945/0x15c0 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 ffff8881cc4d9000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 520 bytes inside of 1024-byte region [ffff8881cc4d9000, ffff8881cc4d9400) The buggy address belongs to the page: page:ffffea0007313600 refcount:1 mapcount:0 mapping:ffff8881da002280 index:0x0 compound_mapcount: 0 raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da002280 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881cc4d9100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cc4d9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881cc4d9200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881cc4d9280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cc4d9300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================