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BUG: KASAN: use-after-free in __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
BUG: KASAN: use-after-free in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
BUG: KASAN: use-after-free in bit_putcs+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff88809e477142 by task syz-executor.3/17756

CPU: 1 PID: 17756 Comm: syz-executor.3 Not tainted 4.14.195-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+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load1_noabort+0x68/0x70 mm/kasan/report.c:427
 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x2fe/0x480 drivers/video/fbdev/core/fbcon.c:1301
 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373
 redraw_screen+0x56e/0x790 drivers/tty/vt/vt.c:705
 vc_do_resize+0xc20/0xe30 drivers/tty/vt/vt.c:973
 vt_ioctl+0x19f7/0x1ea0 drivers/tty/vt/vt_ioctl.c:901
 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 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: 0033:0x45d5b9
RSP: 002b:00007f6a46adac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000001d100 RCX: 000000000045d5b9
RDX: 0000000020000040 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffcd0e2f7bf R14: 00007f6a46adb9c0 R15: 000000000118cf4c

Allocated by task 0:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552
 dst_alloc+0xed/0x6d0 net/core/dst.c:107
 __ip6_dst_alloc net/ipv6/route.c:357 [inline]
 ip6_dst_alloc+0x39/0x2d0 net/ipv6/route.c:370
 icmp6_dst_alloc+0x155/0x580 net/ipv6/route.c:1768
 mld_sendpack+0x527/0xea0 net/ipv6/mcast.c:1647
 mld_send_cr net/ipv6/mcast.c:1956 [inline]
 mld_ifc_timer_expire+0x57c/0xcd0 net/ipv6/mcast.c:2455
 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280
 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319
 __run_timers kernel/time/timer.c:1644 [inline]
 run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1657
 __do_softirq+0x254/0xa1d kernel/softirq.c:288

Freed by task 0:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
 dst_destroy+0x24d/0x390 net/core/dst.c:138
 __rcu_reclaim kernel/rcu/rcu.h:195 [inline]
 rcu_do_batch kernel/rcu/tree.c:2699 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
 rcu_process_callbacks+0x780/0x1180 kernel/rcu/tree.c:2946
 __do_softirq+0x254/0xa1d kernel/softirq.c:288

The buggy address belongs to the object at ffff88809e477000
 which belongs to the cache ip6_dst_cache of size 384
The buggy address is located 322 bytes inside of
 384-byte region [ffff88809e477000, ffff88809e477180)
The buggy address belongs to the page:
page:ffffea0002791dc0 count:1 mapcount:0 mapping:ffff88809e477000 index:0xffff88809e477000
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88809e477000 ffff88809e477000 0000000100000007
raw: ffffea00027aeee0 ffffea000257b6a0 ffff888216345980 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809e477000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809e477080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809e477100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88809e477180: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff88809e477200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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