================================================================== BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:49 [inline] BUG: KASAN: slab-out-of-bounds in vc_do_resize+0xb5e/0x1af0 drivers/tty/vt/vt.c:1250 Read of size 2 at addr ffff8880a25e8764 by task syz-executor.3/16440 CPU: 0 PID: 16440 Comm: syz-executor.3 Not tainted 5.6.0-rc1-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+0x1fb/0x318 lib/dump_stack.c:118 print_address_description+0x74/0x5c0 mm/kasan/report.c:374 __kasan_report+0x149/0x1c0 mm/kasan/report.c:506 kasan_report+0x26/0x50 mm/kasan/common.c:641 check_memory_region_inline mm/kasan/generic.c:182 [inline] check_memory_region+0x2b6/0x2f0 mm/kasan/generic.c:192 memcpy+0x28/0x60 mm/kasan/common.c:127 scr_memcpyw include/linux/vt_buffer.h:49 [inline] vc_do_resize+0xb5e/0x1af0 drivers/tty/vt/vt.c:1250 vc_resize+0x4f/0x60 drivers/tty/vt/vt.c:1304 fbcon_modechanged+0x701/0xdf0 drivers/video/fbdev/core/fbcon.c:2987 fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3045 fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x55e/0x780 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xb9/0xf0 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b3b9 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:00007fe875c6dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fe875c6e6d4 RCX: 000000000045b3b9 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002ea R14: 00000000004c3fb0 R15: 000000000075bf2c Allocated by task 16440: save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc+0x118/0x1c0 mm/kasan/common.c:515 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x254/0x340 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] kzalloc+0x21/0x40 include/linux/slab.h:669 vc_do_resize+0x2af/0x1af0 drivers/tty/vt/vt.c:1187 vc_resize+0x4f/0x60 drivers/tty/vt/vt.c:1304 fbcon_modechanged+0x701/0xdf0 drivers/video/fbdev/core/fbcon.c:2987 fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3045 fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1056 fbcon_resize+0x819/0x11f0 drivers/video/fbdev/core/fbcon.c:2229 resize_screen drivers/tty/vt/vt.c:1126 [inline] vc_do_resize+0x478/0x1af0 drivers/tty/vt/vt.c:1205 vc_resize+0x4f/0x60 drivers/tty/vt/vt.c:1304 fbcon_modechanged+0x701/0xdf0 drivers/video/fbdev/core/fbcon.c:2987 fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3045 fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x55e/0x780 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xb9/0xf0 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8419: save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x12e/0x1e0 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10d/0x220 mm/slab.c:3757 vc_do_resize+0xc8c/0x1af0 drivers/tty/vt/vt.c:1261 vc_resize+0x4f/0x60 drivers/tty/vt/vt.c:1304 fbcon_modechanged+0x701/0xdf0 drivers/video/fbdev/core/fbcon.c:2987 fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3045 fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x55e/0x780 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xb9/0xf0 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a25e8700 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 100 bytes inside of 128-byte region [ffff8880a25e8700, ffff8880a25e8780) The buggy address belongs to the page: page:ffffea0002897a00 refcount:1 mapcount:0 mapping:ffff8880aa400700 index:0xffff8880a25e8000 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea000291c548 ffffea0002484a48 ffff8880aa400700 raw: ffff8880a25e8000 ffff8880a25e8000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a25e8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a25e8680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a25e8700: 00 00 00 00 00 00 00 00 00 00 00 00 04 fc fc fc ^ ffff8880a25e8780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a25e8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================