================================================================== BUG: KASAN: slab-out-of-bounds in soft_cursor+0x3fe/0xdb0 drivers/video/fbdev/core/softcursor.c:70 Read of size 9 at addr ffff888090c78d30 by task syz-executor.1/23895 CPU: 1 PID: 23895 Comm: syz-executor.1 Not tainted 5.8.0-rc7-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+0x1f0/0x31e lib/dump_stack.c:118 print_address_description+0x66/0x5a0 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:183 [inline] check_memory_region+0x2b5/0x2f0 mm/kasan/generic.c:192 memcpy+0x25/0x60 mm/kasan/common.c:105 soft_cursor+0x3fe/0xdb0 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0x178a/0x2180 drivers/video/fbdev/core/bitblit.c:386 hide_cursor+0x7e/0x310 drivers/tty/vt/vt.c:902 redraw_screen+0x148/0x16f0 drivers/tty/vt/vt.c:1006 vc_do_resize+0x154f/0x1d00 drivers/tty/vt/vt.c:1320 vt_ioctl+0x3185/0x3ec0 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl fs/ioctl.c:753 [inline] __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:760 do_syscall_64+0x73/0xe0 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:00007f5fc1390c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001c300 RCX: 000000000045cce9 RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffeebd5100f R14: 00007f5fc13919c0 R15: 000000000078bf0c Allocated by task 11629: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x24b/0x330 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2673 con_font_set drivers/tty/vt/vt.c:4578 [inline] con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4643 vt_ioctl+0x179d/0x3ec0 drivers/tty/vt/vt_ioctl.c:265 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] ksys_ioctl fs/ioctl.c:753 [inline] __do_sys_ioctl fs/ioctl.c:762 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:760 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 11205: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 __do_execve_file+0xbf2/0x2310 fs/exec.c:1963 do_execveat_common fs/exec.c:1980 [inline] do_execve+0x2f/0x40 fs/exec.c:1997 call_usermodehelper_exec_async+0x2df/0x480 kernel/umh.c:112 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff888090c78c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 304 bytes inside of 512-byte region [ffff888090c78c00, ffff888090c78e00) The buggy address belongs to the page: page:ffffea0002431e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888090c78000 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea000260ff08 ffffea000256e0c8 ffff8880aa400a80 raw: ffff888090c78000 ffff888090c78000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888090c78c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888090c78c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888090c78d00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888090c78d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888090c78e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================