================================================================== 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 6 at addr ffff888090e96604 by task kworker/0:3/24923 CPU: 0 PID: 24923 Comm: kworker/0:3 Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient fb_flashcursor 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 fb_flashcursor+0x374/0x3e0 drivers/video/fbdev/core/fbcon.c:417 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Allocated by task 10246: 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:4662 [inline] con_font_op+0xd25/0x1110 drivers/tty/vt/vt.c:4727 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:595 [inline] vt_ioctl+0x1be1/0x2c20 drivers/tty/vt/vt_ioctl.c:846 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 26: 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] kfree_skb.part.0+0xc2/0x350 net/core/skbuff.c:696 kfree_skb+0x7d/0x100 include/linux/refcount.h:270 kauditd_hold_skb+0x155/0x180 kernel/audit.c:575 kauditd_send_queue+0x19d/0x210 kernel/audit.c:734 kauditd_thread+0x7e7/0xb70 kernel/audit.c:860 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 The buggy address belongs to the object at ffff888090e96000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1540 bytes inside of 2048-byte region [ffff888090e96000, ffff888090e96800) The buggy address belongs to the page: page:ffffea000243a580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00023c5648 ffffea0002666d08 ffff8880aa040e00 raw: 0000000000000000 ffff888090e96000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888090e96500: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888090e96580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888090e96600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888090e96680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888090e96700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================