================================================================== BUG: KASAN: slab-out-of-bounds in vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4618 Read of size 2 at addr ffff8880a5475400 by task syz-executor.2/15432 CPU: 0 PID: 15432 Comm: syz-executor.2 Not tainted 4.19.88-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+0x197/0x210 lib/dump_stack.c:118 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:431 vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4618 vcs_write+0x646/0xcf0 drivers/tty/vt/vc_screen.c:526 __vfs_write+0x114/0x810 fs/read_write.c:485 vfs_write+0x20c/0x560 fs/read_write.c:549 ksys_write+0x14f/0x2d0 fs/read_write.c:599 __do_sys_write fs/read_write.c:611 [inline] __se_sys_write fs/read_write.c:608 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:608 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a909 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:00007f7484967c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a909 RDX: 00000001000001bd RSI: 0000000020002300 RDI: 0000000000000004 RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f74849686d4 R13: 00000000004cbdc5 R14: 00000000004e5a58 R15: 00000000ffffffff Allocated by task 1: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15d/0x750 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] kzalloc include/linux/slab.h:709 [inline] vc_do_resize+0x262/0x14a0 drivers/tty/vt/vt.c:1190 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:1307 fbcon_init+0x1062/0x1b00 drivers/video/fbdev/core/fbcon.c:1179 visual_init+0x337/0x620 drivers/tty/vt/vt.c:1054 do_bind_con_driver+0x549/0x8c0 drivers/tty/vt/vt.c:3507 do_take_over_console+0x449/0x590 drivers/tty/vt/vt.c:4068 do_fbcon_takeover+0x116/0x220 drivers/video/fbdev/core/fbcon.c:556 fbcon_fb_registered drivers/video/fbdev/core/fbcon.c:3228 [inline] fbcon_event_notify+0x1786/0x1dba drivers/video/fbdev/core/fbcon.c:3358 notifier_call_chain+0xc2/0x230 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x94/0xb0 kernel/notifier.c:325 fb_notifier_call_chain+0x25/0x30 drivers/video/fbdev/core/fb_notify.c:45 do_register_framebuffer drivers/video/fbdev/core/fbmem.c:1708 [inline] register_framebuffer+0x61d/0xa70 drivers/video/fbdev/core/fbmem.c:1831 vga16fb_probe+0x711/0x825 drivers/video/fbdev/vga16fb.c:1373 platform_drv_probe+0x93/0x160 drivers/base/platform.c:582 really_probe+0x4a0/0x650 drivers/base/dd.c:500 driver_probe_device+0x103/0x1b0 drivers/base/dd.c:661 __device_attach_driver+0x225/0x290 drivers/base/dd.c:748 bus_for_each_drv+0x16c/0x1f0 drivers/base/bus.c:464 __device_attach+0x237/0x350 drivers/base/dd.c:814 device_initial_probe+0x1b/0x20 drivers/base/dd.c:861 bus_probe_device+0x1f7/0x2a0 drivers/base/bus.c:524 device_add+0xb42/0x1760 drivers/base/core.c:1985 platform_device_add+0x366/0x6f0 drivers/base/platform.c:418 vga16fb_init+0x15f/0x1d6 drivers/video/fbdev/vga16fb.c:1431 do_one_initcall+0x107/0x78c init/main.c:883 do_initcall_level init/main.c:951 [inline] do_initcalls init/main.c:959 [inline] do_basic_setup init/main.c:977 [inline] kernel_init_freeable+0x4d4/0x5c8 init/main.c:1144 kernel_init+0x12/0x1c4 init/main.c:1061 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8880a5474140 which belongs to the cache kmalloc-8192 of size 8192 The buggy address is located 4800 bytes inside of 8192-byte region [ffff8880a5474140, ffff8880a5476140) The buggy address belongs to the page: page:ffffea0002951d00 count:1 mapcount:0 mapping:ffff88812c315080 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea0002991f08 ffffea00028d8208 ffff88812c315080 raw: 0000000000000000 ffff8880a5474140 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a5475300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a5475380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a5475400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a5475480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a5475500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================