RDX: 0000000000000000 RSI: 000000000000ae41 RDI: 0000000000000008 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003a3 R14: 00000000004c652f R15: 00007f4b1ca486d4 ================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:663 [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+0xa8a/0xc00 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88808fa11e64 by task syz-executor.1/7804 CPU: 0 PID: 7804 Comm: syz-executor.1 Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xa8a/0xc00 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x3bb/0x480 drivers/video/fbdev/core/fbcon.c:1301 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373 redraw_screen+0x562/0x760 drivers/tty/vt/vt.c:705 vc_do_resize+0xbe0/0xde0 drivers/tty/vt/vt.c:967 vt_ioctl+0x1a64/0x1f20 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0x6c9/0x1220 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45cba9 RSP: 002b:00007f4b1ca26c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004f3d80 RCX: 000000000045cba9 RDX: 0000000020000000 RSI: 000000000000560a RDI: 000000000000000a RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000682 R14: 00000000004c9910 R15: 00007f4b1ca276d4 Allocated by task 29900: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15a/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] fbcon_set_font+0x2f8/0x7c0 drivers/video/fbdev/core/fbcon.c:2621 con_font_set drivers/tty/vt/vt.c:4182 [inline] con_font_op+0xb73/0xf70 drivers/tty/vt/vt.c:4247 vt_ioctl+0x736/0x1f20 drivers/tty/vt/vt_ioctl.c:928 tty_ioctl+0x6c9/0x1220 drivers/tty/tty_io.c:2661 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 28844: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcb/0x260 mm/slab.c:3815 skb_free_head+0x83/0xa0 net/core/skbuff.c:554 skb_release_data+0x57e/0x7d0 net/core/skbuff.c:574 skb_release_all+0x46/0x60 net/core/skbuff.c:631 __kfree_skb net/core/skbuff.c:645 [inline] consume_skb+0xa7/0x330 net/core/skbuff.c:705 netlink_broadcast_filtered+0x2b3/0x9d0 net/netlink/af_netlink.c:1489 kobject_uevent_env+0x819/0xc50 lib/kobject_uevent.c:495 device_del+0x642/0xa80 drivers/base/core.c:2081 device_unregister+0x11/0x30 drivers/base/core.c:2103 bdi_unregister+0x406/0x5d0 mm/backing-dev.c:946 release_bdi mm/backing-dev.c:962 [inline] kref_put include/linux/kref.h:70 [inline] bdi_put+0x127/0x160 mm/backing-dev.c:971 generic_shutdown_super+0x2aa/0x370 fs/super.c:460 kill_anon_super+0x38/0x50 fs/super.c:1006 deactivate_locked_super+0x6c/0xd0 fs/super.c:319 deactivate_super fs/super.c:350 [inline] deactivate_super+0x7f/0xa0 fs/super.c:346 cleanup_mnt+0xad/0x140 fs/namespace.c:1183 task_work_run+0x113/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff88808fa11d00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 356 bytes inside of 512-byte region [ffff88808fa11d00, ffff88808fa11f00) The buggy address belongs to the page: page:ffffea00023e8440 count:1 mapcount:0 mapping:ffff88808fa11080 index:0xffff88808fa11300 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff88808fa11080 ffff88808fa11300 0000000100000003 raw: ffffea00023fcd20 ffffea0002524ce0 ffff8880aa800940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808fa11d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88808fa11d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88808fa11e00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88808fa11e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88808fa11f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================