================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline] BUG: KASAN: slab-out-of-bounds in soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70 Read of size 8 at addr ffff88805ada5d10 by task syz-executor.0/25887 CPU: 1 PID: 25887 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] soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0x1166/0x17d0 drivers/video/fbdev/core/bitblit.c:386 fbcon_cursor+0x52b/0x650 drivers/video/fbdev/core/fbcon.c:1411 hide_cursor+0x85/0x280 drivers/tty/vt/vt.c:902 redraw_screen+0x5e1/0x770 drivers/tty/vt/vt.c:1006 vc_do_resize+0x1111/0x13f0 drivers/tty/vt/vt.c:1320 vt_ioctl+0x2037/0x2670 drivers/tty/vt/vt_ioctl.c:901 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:00007fd756a41c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001c300 RCX: 000000000045cce9 RDX: 0000000020000b00 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffe95438a2f R14: 00007fd756a429c0 R15: 000000000078bf0c Allocated by task 22867: 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 22579: 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 skb_free_head net/core/skbuff.c:590 [inline] skb_release_data+0x6d9/0x910 net/core/skbuff.c:610 skb_release_all net/core/skbuff.c:664 [inline] __kfree_skb net/core/skbuff.c:678 [inline] consume_skb net/core/skbuff.c:837 [inline] consume_skb+0xc2/0x160 net/core/skbuff.c:831 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x53b/0x7d0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x331/0x810 net/socket.c:2352 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406 __sys_sendmmsg+0x195/0x480 net/socket.c:2496 __do_sys_sendmmsg net/socket.c:2525 [inline] __se_sys_sendmmsg net/socket.c:2522 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2522 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 ffff88805ada5c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 272 bytes inside of 512-byte region [ffff88805ada5c00, ffff88805ada5e00) The buggy address belongs to the page: page:ffffea00016b6940 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805ada5400 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0001a61548 ffffea00029c3f48 ffff8880aa000a80 raw: ffff88805ada5400 ffff88805ada5000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805ada5c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805ada5c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88805ada5d00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805ada5d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805ada5e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================