================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:348 [inline] BUG: KASAN: slab-out-of-bounds in soft_cursor+0x439/0xa30 drivers/video/fbdev/core/softcursor.c:70 Read of size 16 at addr ffff888095036290 by task syz-executor.2/11625 CPU: 0 PID: 11625 Comm: syz-executor.2 Not tainted 4.19.101-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+0x197/0x210 lib/dump_stack.c:118 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x123/0x190 mm/kasan/kasan.c:267 memcpy+0x24/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:348 [inline] soft_cursor+0x439/0xa30 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0x12fc/0x1a60 drivers/video/fbdev/core/bitblit.c:386 fbcon_cursor+0x58a/0x7b0 drivers/video/fbdev/core/fbcon.c:1369 hide_cursor+0x9e/0x300 drivers/tty/vt/vt.c:895 redraw_screen+0x2ee/0x8e0 drivers/tty/vt/vt.c:988 vc_do_resize+0x118e/0x14a0 drivers/tty/vt/vt.c:1287 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:1307 vt_ioctl+0x1fe0/0x2530 drivers/tty/vt/vt_ioctl.c:887 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b399 Code: ad 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4a46feac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4a46feb6d4 RCX: 000000000045b399 RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000666 R14: 00000000004c7f04 R15: 000000000075bf2c Allocated by task 8052: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 __do_kmalloc mm/slab.c:3727 [inline] __kmalloc+0x15d/0x750 mm/slab.c:3736 kmalloc include/linux/slab.h:520 [inline] fbcon_set_font+0x32d/0x860 drivers/video/fbdev/core/fbcon.c:2641 con_font_set drivers/tty/vt/vt.c:4492 [inline] con_font_op+0xe18/0x1250 drivers/tty/vt/vt.c:4557 vt_ioctl+0xd2e/0x2530 drivers/tty/vt/vt_ioctl.c:913 tty_ioctl+0x7f3/0x1510 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8136: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kfree+0xcf/0x220 mm/slab.c:3822 skb_free_head+0x99/0xc0 net/core/skbuff.c:554 skb_release_data+0x619/0x8d0 net/core/skbuff.c:574 skb_release_all+0x4d/0x60 net/core/skbuff.c:631 __kfree_skb+0x16/0x30 net/core/skbuff.c:645 sk_wmem_free_skb include/net/sock.h:1462 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:1751 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3153 [inline] tcp_ack+0x1e6d/0x5170 net/ipv4/tcp_input.c:3678 tcp_rcv_established+0x131d/0x1f10 net/ipv4/tcp_input.c:5566 tcp_v4_do_rcv+0x61f/0x8d0 net/ipv4/tcp_ipv4.c:1535 sk_backlog_rcv include/net/sock.h:946 [inline] __release_sock+0x129/0x390 net/core/sock.c:2339 release_sock+0x59/0x1c0 net/core/sock.c:2855 tcp_sendmsg+0x3b/0x50 net/ipv4/tcp.c:1453 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:632 sock_write_iter+0x2cb/0x400 net/socket.c:901 call_write_iter include/linux/fs.h:1820 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x587/0x810 fs/read_write.c:487 vfs_write+0x20c/0x560 fs/read_write.c:549 ksys_write+0x14f/0x2d0 fs/read_write.c:599 __do_sys_write fs/read_write.c:611 [inline] __se_sys_write fs/read_write.c:608 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:608 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888095036040 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 592 bytes inside of 1024-byte region [ffff888095036040, ffff888095036440) The buggy address belongs to the page: page:ffffea0002540d80 count:1 mapcount:0 mapping:ffff88812c31cac0 index:0xffff888095037240 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea0001f88f88 ffffea0002813988 ffff88812c31cac0 raw: ffff888095037240 ffff888095036040 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888095036180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888095036200: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc >ffff888095036280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888095036300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888095036380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc 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