kobject: 'loop1' (ffff8880a41073e0): kobject_uevent_env kobject: 'loop1' (ffff8880a41073e0): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop4' (ffff8880a41e2420): kobject_uevent_env kobject: 'loop4' (ffff8880a41e2420): fill_kobj_path: path = '/devices/virtual/block/loop4' ================================================================== BUG: KASAN: use-after-free in fbcon_cursor+0x5c6/0x6f0 drivers/video/fbdev/core/fbcon.c:1325 Read of size 2 at addr ffff8880a14f580c by task syz-executor.3/8047 CPU: 1 PID: 8047 Comm: syz-executor.3 Not tainted 4.14.158-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428 fbcon_cursor+0x5c6/0x6f0 drivers/video/fbdev/core/fbcon.c:1325 fbcon_scrolldelta+0x5a4/0x1100 drivers/video/fbdev/core/fbcon.c:2832 fbcon_set_origin+0x39/0x50 drivers/video/fbdev/core/fbcon.c:2883 set_origin+0x2d8/0x3c0 drivers/tty/vt/vt.c:613 vc_do_resize+0x686/0xec0 drivers/tty/vt/vt.c:934 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:974 vt_ioctl+0x1282/0x2170 drivers/tty/vt/vt_ioctl.c:840 tty_ioctl+0x841/0x1320 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a909 RSP: 002b:00007f0b23d9ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a909 RDX: 0000000020000000 RSI: 0000000000005609 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0b23d9b6d4 R13: 00000000004c7009 R14: 00000000004dd670 R15: 00000000ffffffff Allocated by task 7985: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15d/0x7a0 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:661 [inline] vc_do_resize+0x1da/0xec0 drivers/tty/vt/vt.c:872 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:974 vt_ioctl+0x1282/0x2170 drivers/tty/vt/vt_ioctl.c:840 tty_ioctl+0x841/0x1320 drivers/tty/tty_io.c:2661 do