================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:399 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2475 Read of size 8 at addr ffff8880916a6710 by task syz-executor.0/13709 CPU: 0 PID: 13709 Comm: syz-executor.0 Not tainted 5.8.0-next-20200812-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/0x497 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:399 [inline] fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2475 con_font_get drivers/tty/vt/vt.c:4570 [inline] con_font_op+0x1f5/0x1110 drivers/tty/vt/vt.c:4729 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:514 [inline] vt_io_ioctl drivers/tty/vt/vt_ioctl.c:611 [inline] vt_ioctl+0x18fe/0x2c20 drivers/tty/vt/vt_ioctl.c:846 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d189 Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc1ffb67c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000000e540 RCX: 000000000045d189 RDX: 0000000020000440 RSI: 0000000000004b6b RDI: 0000000000000003 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffd195cffbf R14: 00007fc1ffb689c0 R15: 000000000118cf4c Allocated by task 9323: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x1a8/0x320 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [inline] fbcon_set_font+0x34f/0x8b0 drivers/video/fbdev/core/fbcon.c:2673 con_font_set drivers/tty/vt/vt.c:4662 [inline] con_font_op+0xd25/0x1110 drivers/tty/vt/vt.c:4727 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:595 [inline] vt_ioctl+0x1be1/0x2c20 drivers/tty/vt/vt_ioctl.c:846 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Last call_rcu(): kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_record_aux_stack+0x82/0xb0 mm/kasan/generic.c:346 __call_rcu kernel/rcu/tree.c:2894 [inline] call_rcu+0x14f/0x7e0 kernel/rcu/tree.c:2968 put_event kernel/events/core.c:4906 [inline] perf_event_release_kernel+0xa24/0xe00 kernel/events/core.c:5021 perf_release+0x33/0x40 kernel/events/core.c:5031 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:139 [inline] exit_to_user_mode_prepare+0x195/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Second to last call_rcu(): kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_record_aux_stack+0x82/0xb0 mm/kasan/generic.c:346 __call_rcu kernel/rcu/tree.c:2894 [inline] call_rcu+0x14f/0x7e0 kernel/rcu/tree.c:2968 netlink_release+0xd43/0x1cf0 net/netlink/af_netlink.c:802 __sock_release+0xcd/0x280 net/socket.c:596 sock_close+0x18/0x20 net/socket.c:1277 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:139 [inline] exit_to_user_mode_prepare+0x195/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880916a6000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1808 bytes inside of 2048-byte region [ffff8880916a6000, ffff8880916a6800) The buggy address belongs to the page: page:0000000088f032d0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x916a6 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a294c8 ffffea0002490548 ffff8880aa040800 raw: 0000000000000000 ffff8880916a6000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880916a6600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880916a6680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880916a6700: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880916a6780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880916a6800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================