================================================================== BUG: KASAN: use-after-free in strlen+0x79/0x90 lib/string.c:527 Read of size 1 at addr ffff8881ce035a08 by task syz-executor.2/9574 CPU: 1 PID: 9574 Comm: syz-executor.2 Not tainted 5.4.0-rc3+ #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+0xca/0x13e lib/dump_stack.c:113 print_address_description.constprop.0+0x36/0x50 mm/kasan/report.c:374 __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:634 strlen+0x79/0x90 lib/string.c:527 strlen include/linux/string.h:300 [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:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd2d/0x1330 fs/ioctl.c:696 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:718 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459a59 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fbca154bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459a59 RDX: 0000000020000200 RSI: 0000000080404507 RDI: 0000000000000007 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbca154c6d4 R13: 00000000004c1cca R14: 00000000004d5430 R15: 00000000ffffffff Allocated by task 2740: save_stack+0x1b/0x80 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:510 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:483 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2772 [inline] __kmalloc_node_track_caller+0xfc/0x3d0 mm/slub.c:4375 __kmalloc_reserve.isra.0+0x39/0xe0 net/core/skbuff.c:141 __alloc_skb+0xef/0x5a0 net/core/skbuff.c:209 alloc_skb include/linux/skbuff.h:1049 [inline] alloc_uevent_skb+0x7b/0x210 lib/kobject_uevent.c:289 uevent_net_broadcast_untagged lib/kobject_uevent.c:325 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:408 [inline] kobject_uevent_env+0x8ee/0x1150 lib/kobject_uevent.c:592 __device_release_driver drivers/base/dd.c:1154 [inline] device_release_driver_internal+0x3ef/0x500 drivers/base/dd.c:1165 bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:532 device_del+0x420/0xb20 drivers/base/core.c:2375 usb_disconnect+0x4c3/0x8d0 drivers/usb/core/hub.c:2225 hub_port_connect drivers/usb/core/hub.c:5034 [inline] hub_port_connect_change drivers/usb/core/hub.c:5323 [inline] port_event drivers/usb/core/hub.c:5469 [inline] hub_event+0x16ca/0x37e0 drivers/usb/core/hub.c:5551 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 worker_thread+0x96/0xe20 kernel/workqueue.c:2415 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 239: save_stack+0x1b/0x80 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] kasan_set_free_info mm/kasan/common.c:332 [inline] __kasan_slab_free+0x130/0x180 mm/kasan/common.c:471 slab_free_hook mm/slub.c:1424 [inline] slab_free_freelist_hook mm/slub.c:1475 [inline] slab_free mm/slub.c:3018 [inline] kfree+0xe4/0x320 mm/slub.c:3967 skb_free_head+0x8b/0xa0 net/core/skbuff.c:591 skb_release_data+0x41f/0x7c0 net/core/skbuff.c:611 skb_release_all+0x46/0x60 net/core/skbuff.c:665 __kfree_skb net/core/skbuff.c:679 [inline] consume_skb net/core/skbuff.c:838 [inline] consume_skb+0xd9/0x320 net/core/skbuff.c:832 skb_free_datagram+0x16/0xf0 net/core/datagram.c:328 netlink_recvmsg+0x65e/0xee0 net/netlink/af_netlink.c:1996 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg net/socket.c:889 [inline] sock_recvmsg+0xca/0x110 net/socket.c:885 ___sys_recvmsg+0x271/0x5c0 net/socket.c:2480 __sys_recvmsg+0xe9/0x1b0 net/socket.c:2537 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881ce035800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 520 bytes inside of 1024-byte region [ffff8881ce035800, ffff8881ce035c00) The buggy address belongs to the page: page:ffffea0007380c00 refcount:1 mapcount:0 mapping:ffff8881da002280 index:0xffff8881ce030000 compound_mapcount: 0 flags: 0x200000000010200(slab|head) raw: 0200000000010200 ffffea0007546e08 ffffea0007288008 ffff8881da002280 raw: ffff8881ce030000 0000000000100005 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ce035900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ce035980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881ce035a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ce035a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ce035b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================