================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:654 [inline] BUG: KASAN: slab-out-of-bounds in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] BUG: KASAN: slab-out-of-bounds in bit_putcs+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88805c7de750 by task syz-executor.5/9350 CPU: 1 PID: 9350 Comm: syz-executor.5 Not tainted 5.8.0-next-20200812-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 __fb_pad_aligned_buffer include/linux/fb.h:654 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xbb6/0xd20 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x33c/0x3f0 drivers/video/fbdev/core/fbcon.c:1362 do_update_region+0x399/0x630 drivers/tty/vt/vt.c:675 redraw_screen+0x64e/0x770 drivers/tty/vt/vt.c:1034 vc_do_resize+0xef0/0x1180 drivers/tty/vt/vt.c:1325 vt_resizex drivers/tty/vt/vt_ioctl.c:814 [inline] vt_ioctl+0xeba/0x2c20 drivers/tty/vt/vt_ioctl.c:1026 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: 0033:0x45ce69 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:00007f17cb3bfc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001c340 RCX: 000000000045ce69 RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffe44e4b86f R14: 00007f17cb3c09c0 R15: 000000000118bf2c Allocated by task 3636: 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 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:506 [inline] vt_io_ioctl drivers/tty/vt/vt_ioctl.c:611 [inline] vt_ioctl+0x1a9f/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 Last call_rcu(): kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_record_aux_stack+0x82/0xb0 mm/kasan/generic.c:346 __call_rcu kernel/rcu/tree.c:2894 [inline] call_rcu+0x14f/0x7e0 kernel/rcu/tree.c:2968 qdisc_put+0xcd/0xe0 net/sched/sch_generic.c:987 shutdown_scheduler_queue net/sched/sch_generic.c:1308 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2229 [inline] dev_shutdown+0x11b/0x499 net/sched/sch_generic.c:1314 rollback_registered_many+0x62f/0x1210 net/core/dev.c:9274 rollback_registered net/core/dev.c:9326 [inline] unregister_netdevice_queue+0x2dd/0x570 net/core/dev.c:10407 unregister_netdevice include/linux/netdevice.h:2774 [inline] __tun_detach+0xff6/0x1310 drivers/net/tun.c:691 tun_detach drivers/net/tun.c:708 [inline] tun_chr_close+0xd9/0x180 drivers/net/tun.c:3408 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:139 [inline] exit_to_user_mode_prepare+0x195/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff88805c7de000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1872 bytes inside of 2048-byte region [ffff88805c7de000, ffff88805c7de800) The buggy address belongs to the page: page:0000000087aba601 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5c7de flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00028cfac8 ffffea0002a1cfc8 ffff8880aa040800 raw: 0000000000000000 ffff88805c7de000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805c7de600: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805c7de680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805c7de700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805c7de780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805c7de800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================