================================================================== 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:2475 Read of size 16 at addr ffff88809839ca10 by task syz-executor.5/25091 CPU: 1 PID: 25091 Comm: syz-executor.5 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] fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2475 con_font_get drivers/tty/vt/vt.c:4486 [inline] con_font_op+0x1f5/0x1110 drivers/tty/vt/vt.c:4645 vt_ioctl+0x16dc/0x2670 drivers/tty/vt/vt_ioctl.c:980 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 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:00007fdbfe700c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000000f5c0 RCX: 000000000045cce9 RDX: 0000000020000400 RSI: 0000000000004b72 RDI: 0000000000000004 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffcca36353f R14: 00007fdbfe7019c0 R15: 000000000078bf0c Allocated by task 10105: 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] fbcon_set_font+0x34f/0x8b0 drivers/video/fbdev/core/fbcon.c:2673 con_font_set drivers/tty/vt/vt.c:4578 [inline] con_font_op+0xd25/0x1110 drivers/tty/vt/vt.c:4643 vt_ioctl+0x1180/0x2670 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 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 6974: 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 kvfree+0x42/0x50 mm/util.c:603 __do_replace+0x696/0x880 net/ipv4/netfilter/ip_tables.c:1087 do_replace net/ipv4/netfilter/ip_tables.c:1140 [inline] do_ipt_set_ctl+0x2e8/0x460 net/ipv4/netfilter/ip_tables.c:1672 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline] nf_setsockopt+0x6f/0xc0 net/netfilter/nf_sockopt.c:115 ip_setsockopt net/ipv4/ip_sockglue.c:1319 [inline] ip_setsockopt+0xd8/0xf0 net/ipv4/ip_sockglue.c:1299 tcp_setsockopt+0x86/0xd0 net/ipv4/tcp.c:3334 __sys_setsockopt+0x24a/0x480 net/socket.c:2127 __do_sys_setsockopt net/socket.c:2143 [inline] __se_sys_setsockopt net/socket.c:2140 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2140 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 ffff88809839c800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 528 bytes inside of 1024-byte region [ffff88809839c800, ffff88809839cc00) The buggy address belongs to the page: page:ffffea000260e700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00009ba448 ffffea00025ac3c8 ffff8880aa000c40 raw: 0000000000000000 ffff88809839c000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809839c900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88809839c980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88809839ca00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88809839ca80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809839cb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================