================================================================== 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+0xab7/0xc30 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff8880a02e2753 by task syz-executor.5/12118 CPU: 1 PID: 12118 Comm: syz-executor.5 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:00007fa1a9ce5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000001cfc0 RCX: 000000000045d5b9 RDX: 0000000020000a00 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffddf146edf R14: 00007fa1a9ce69c0 R15: 000000000118cf4c Allocated by task 7888: 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 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15a/0x400 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] fbcon_set_font+0x2fb/0x7c0 drivers/video/fbdev/core/fbcon.c:2621 con_font_set drivers/tty/vt/vt.c:4189 [inline] con_font_op+0xb69/0xf60 drivers/tty/vt/vt.c:4254 vt_ioctl+0xd91/0x1ea0 drivers/tty/vt/vt_ioctl.c:928 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 Freed by task 6355: 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] kfree+0xc9/0x250 mm/slab.c:3815 skb_free_head net/core/skbuff.c:554 [inline] skb_release_data+0x5f6/0x820 net/core/skbuff.c:574 skb_release_all net/core/skbuff.c:631 [inline] __kfree_skb net/core/skbuff.c:645 [inline] consume_skb+0xe0/0x380 net/core/skbuff.c:705 __dev_kfree_skb_any+0x7a/0xa0 net/core/dev.c:2529 dev_consume_skb_any include/linux/netdevice.h:3276 [inline] free_old_xmit_skbs+0x176/0x290 drivers/net/virtio_net.c:1137 start_xmit+0x148/0x1460 drivers/net/virtio_net.c:1299 __netdev_start_xmit include/linux/netdevice.h:4039 [inline] netdev_start_xmit include/linux/netdevice.h:4048 [inline] xmit_one net/core/dev.c:3005 [inline] dev_hard_start_xmit+0x188/0x890 net/core/dev.c:3021 sch_direct_xmit+0x251/0x500 net/sched/sch_generic.c:186 __dev_xmit_skb net/core/dev.c:3214 [inline] __dev_queue_xmit+0x1ab0/0x2480 net/core/dev.c:3489 neigh_hh_output include/net/neighbour.h:490 [inline] neigh_output include/net/neighbour.h:498 [inline] ip_finish_output2+0x9db/0x12f0 net/ipv4/ip_output.c:229 ip_finish_output+0x37b/0xc30 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:239 [inline] ip_output+0x1cd/0x510 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:470 [inline] ip_local_out+0x93/0x170 net/ipv4/ip_output.c:124 ip_queue_xmit+0x7d3/0x1a80 net/ipv4/ip_output.c:504 __tcp_transmit_skb+0x17e2/0x2cb0 net/ipv4/tcp_output.c:1133 __tcp_send_ack.part.0+0x399/0x580 net/ipv4/tcp_output.c:3645 __tcp_send_ack net/ipv4/tcp_output.c:3651 [inline] tcp_send_ack+0x6f/0x90 net/ipv4/tcp_output.c:3651 __tcp_ack_snd_check+0xf6/0x380 net/ipv4/tcp_input.c:5154 tcp_rcv_established+0x120d/0x17a0 net/ipv4/tcp_input.c:5544 tcp_v4_do_rcv+0x541/0x7d0 net/ipv4/tcp_ipv4.c:1476 sk_backlog_rcv include/net/sock.h:921 [inline] __release_sock+0x12a/0x350 net/core/sock.c:2269 release_sock+0x54/0x1b0 net/core/sock.c:2805 tcp_recvmsg+0x66d/0x1c30 net/ipv4/tcp.c:2013 inet_recvmsg+0xef/0x4d0 net/ipv4/af_inet.c:793 sock_recvmsg_nosec net/socket.c:819 [inline] sock_recvmsg net/socket.c:826 [inline] sock_recvmsg net/socket.c:822 [inline] sock_read_iter+0x2be/0x3f0 net/socket.c:903 call_read_iter include/linux/fs.h:1772 [inline] new_sync_read fs/read_write.c:401 [inline] __vfs_read+0x449/0x620 fs/read_write.c:413 vfs_read+0x139/0x340 fs/read_write.c:447 SYSC_read fs/read_write.c:574 [inline] SyS_read+0xf2/0x210 fs/read_write.c:567 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880a02e2480 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 723 bytes inside of 1024-byte region [ffff8880a02e2480, ffff8880a02e2880) The buggy address belongs to the page: page:ffffea000280b880 count:1 mapcount:0 mapping:ffff8880a02e2000 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffff8880a02e2000 0000000000000000 0000000100000007 raw: ffffea0002828520 ffffea0002849520 ffff88812fe52ac0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a02e2600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a02e2680: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a02e2700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a02e2780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a02e2800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================