================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2475 Read of size 16 at addr ffff88804b136a10 by task syz-executor.3/5912 CPU: 0 PID: 5912 Comm: syz-executor.3 Not tainted 5.9.0-rc1-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/0x497 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] fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2475 con_font_get drivers/tty/vt/vt.c:4570 [inline] con_font_op+0x1f5/0x1110 drivers/tty/vt/vt.c:4729 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 RIP: 0033:0x45d4d9 Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f72b1a95c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000000f280 RCX: 000000000045d4d9 RDX: 0000000020000340 RSI: 0000000000004b60 RDI: 0000000000000003 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffddff5ad4f R14: 00007f72b1a969c0 R15: 000000000118cf4c Allocated by task 18034: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x1a8/0x320 mm/slab.c:3664 kmalloc include/linux/slab.h:559 [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 The buggy address belongs to the object at ffff88804b136000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2576 bytes inside of 4096-byte region [ffff88804b136000, ffff88804b137000) The buggy address belongs to the page: page:0000000081480e7e refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4b136 head:0000000081480e7e order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00006f4508 ffffea00012cd388 ffff8880aa040900 raw: 0000000000000000 ffff88804b136000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88804b136900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88804b136980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88804b136a00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88804b136a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88804b136b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================