================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline] 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+0x9d3/0x13f0 drivers/tty/vt/vt.c:1280 Read of size 2 at addr ffff8880433a0d90 by task syz-executor.5/4000 CPU: 0 PID: 4000 Comm: syz-executor.5 Not tainted 5.8.0-rc5-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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 memcpy+0x20/0x60 mm/kasan/common.c:105 memcpy include/linux/string.h:406 [inline] scr_memcpyw include/linux/vt_buffer.h:49 [inline] vc_do_resize+0x9d3/0x13f0 drivers/tty/vt/vt.c:1280 fbcon_modechanged+0x36c/0x710 drivers/video/fbdev/core/fbcon.c:2990 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1d9 Code: Bad RIP value. RSP: 002b:00007fe749348c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000000ce80 RCX: 000000000045c1d9 RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 0000000000c9fb6f R14: 00007fe7493499c0 R15: 000000000078bf0c Allocated by task 4000: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x17a/0x340 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] kzalloc include/linux/slab.h:669 [inline] vc_do_resize+0x2fc/0x13f0 drivers/tty/vt/vt.c:1217 fbcon_modechanged+0x36c/0x710 drivers/video/fbdev/core/fbcon.c:2990 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056 fbcon_resize+0x575/0x610 drivers/video/fbdev/core/fbcon.c:2231 resize_screen drivers/tty/vt/vt.c:1156 [inline] vc_do_resize+0x53b/0x13f0 drivers/tty/vt/vt.c:1235 fbcon_modechanged+0x36c/0x710 drivers/video/fbdev/core/fbcon.c:2990 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:753 __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl fs/ioctl.c:760 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 3070: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x103/0x2c0 mm/slab.c:3757 call_usermodehelper_freeinfo kernel/umh.c:48 [inline] umh_complete+0x81/0x90 kernel/umh.c:62 call_usermodehelper_exec_async+0x460/0x710 kernel/umh.c:122 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff8880433a0d00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 144 bytes inside of 192-byte region [ffff8880433a0d00, ffff8880433a0dc0) The buggy address belongs to the page: page:ffffea00010ce800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880433a0400 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00024d1288 ffffea0000defcc8 ffff8880aa000000 raw: ffff8880433a0400 ffff8880433a0000 000000010000000f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880433a0c80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880433a0d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880433a0d80: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880433a0e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880433a0e80: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================