================================================================== BUG: KASAN: use-after-free in memcpy include/linux/string.h:406 [inline] BUG: KASAN: use-after-free in scr_memcpyw include/linux/vt_buffer.h:49 [inline] BUG: KASAN: use-after-free in vc_do_resize+0x9d6/0x13f0 drivers/tty/vt/vt.c:1286 Read of size 2 at addr ffff8880a28e1782 by task syz-executor.0/7089 CPU: 1 PID: 7089 Comm: syz-executor.0 Not tainted 5.8.0-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+0x9d6/0x13f0 drivers/tty/vt/vt.c:1286 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: 0033:0x45cce9 Code: 2d 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1fabeb5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000000d540 RCX: 000000000045cce9 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffd113d190f R14: 00007f1fabeb69c0 R15: 000000000078bf0c Allocated by task 7088: 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] tomoyo_encode2.part.0+0xe9/0x3a0 security/tomoyo/realpath.c:45 tomoyo_encode2 security/tomoyo/realpath.c:31 [inline] tomoyo_encode+0x28/0x50 security/tomoyo/realpath.c:80 tomoyo_path_perm+0x35f/0x3f0 security/tomoyo/file.c:831 tomoyo_path_symlink+0x94/0xe0 security/tomoyo/tomoyo.c:200 security_path_symlink+0xdf/0x150 security/security.c:1109 do_symlinkat+0x123/0x2c0 fs/namei.c:3978 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 7088: 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 tomoyo_path_perm+0x3a7/0x3f0 security/tomoyo/file.c:840 tomoyo_path_symlink+0x94/0xe0 security/tomoyo/tomoyo.c:200 security_path_symlink+0xdf/0x150 security/security.c:1109 do_symlinkat+0x123/0x2c0 fs/namei.c:3978 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880a28e1780 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 2 bytes inside of 32-byte region [ffff8880a28e1780, ffff8880a28e17a0) The buggy address belongs to the page: page:ffffea00028a3840 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a28e1fc1 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00029cb8c8 ffff8880aa001240 ffff8880aa0001c0 raw: ffff8880a28e1fc1 ffff8880a28e1000 0000000100000027 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a28e1680: fb fb fb fb fc fc fc fc 00 00 01 fc fc fc fc fc ffff8880a28e1700: 00 00 00 fc fc fc fc fc fb fb fb fb fc fc fc fc >ffff8880a28e1780: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff8880a28e1800: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8880a28e1880: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ==================================================================