================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2474 Read of size 2 at addr ffff88808bbca510 by task syz-executor.0/27522 CPU: 0 PID: 27522 Comm: syz-executor.0 Not tainted 5.7.0-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x413 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+0x141/0x190 mm/kasan/generic.c:192 memcpy+0x20/0x60 mm/kasan/common.c:105 memcpy include/linux/string.h:406 [inline] fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2474 con_font_get drivers/tty/vt/vt.c:4479 [inline] con_font_op+0x1f7/0x1160 drivers/tty/vt/vt.c:4638 vt_ioctl+0x1740/0x2640 drivers/tty/vt/vt_ioctl.c:980 tty_ioctl+0xedc/0x1440 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca69 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff8ae093c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e7040 RCX: 000000000045ca69 RDX: 0000000020000400 RSI: 0000000000004b72 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000379 R14: 00000000004c60fd R15: 00007ff8ae0946d4 Allocated by task 20323: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:494 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:467 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x161/0x7a0 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] fbcon_set_font+0x331/0x870 drivers/video/fbdev/core/fbcon.c:2672 con_font_set drivers/tty/vt/vt.c:4571 [inline] con_font_op+0xd65/0x1160 drivers/tty/vt/vt.c:4636 vt_ioctl+0xb9b/0x2640 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0xedc/0x1440 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 25: 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+0xf7/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x109/0x2b0 mm/slab.c:3757 batadv_iv_send_outstanding_bat_ogm_packet+0x2b5/0x7c0 net/batman-adv/bat_iv_ogm.c:1728 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 The buggy address belongs to the object at ffff88808bbca400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 272 bytes inside of 512-byte region [ffff88808bbca400, ffff88808bbca600) The buggy address belongs to the page: page:ffffea00022ef280 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88808bbca000 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00027cfdc8 ffffea0002426b08 ffff8880aa000a80 raw: ffff88808bbca000 ffff88808bbca000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808bbca400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88808bbca480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88808bbca500: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88808bbca580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808bbca600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================