================================================================== 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 4 at addr ffff88804b346ab4 by task syz-executor.0/9997 CPU: 1 PID: 9997 Comm: syz-executor.0 Not tainted 4.19.97-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 update_region+0x140/0x1a0 drivers/tty/vt/vt.c:694 vcs_write+0x45e/0xd50 drivers/tty/vt/vc_screen.c:604 __vfs_write+0x114/0x810 fs/read_write.c:485 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 RIP: 0033:0x45b349 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:00007ff15e913c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff15e9146d4 RCX: 000000000045b349 RDX: 000000000000104d RSI: 0000000020001c80 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000c7b R14: 00000000004cd61b R15: 000000000075bf2c Allocated by task 11028: 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 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:244 [inline] vt_ioctl+0x35a/0x2530 drivers/tty/vt/vt_ioctl.c:930 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 0: (stack is not available) The buggy address belongs to the object at ffff88804b346600 which belongs to the cache kmalloc-2048 of size 2048 The buggy address is located 1204 bytes inside of 2048-byte region [ffff88804b346600, ffff88804b346e00) The buggy address belongs to the page: page:ffffea00012cd180 count:1 mapcount:0 mapping:ffff88812c31cc40 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea00020ef488 ffffea00020ee808 ffff88812c31cc40 raw: 0000000000000000 ffff88804b346600 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88804b346980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88804b346a00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88804b346a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88804b346b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804b346b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================