================================================================== BUG: KASAN: slab-out-of-bounds in __fb_pad_aligned_buffer syzkaller/managers/linux-4-14/kernel/./include/linux/fb.h:663 [inline] BUG: KASAN: slab-out-of-bounds in bit_putcs_aligned syzkaller/managers/linux-4-14/kernel/drivers/video/fbdev/core/bitblit.c:96 [inline] BUG: KASAN: slab-out-of-bounds in bit_putcs+0xab7/0xc30 syzkaller/managers/linux-4-14/kernel/drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88809c835be8 by task agetty/10467 CPU: 0 PID: 10467 Comm: agetty Not tainted 4.14.218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 syzkaller/managers/linux-4-14/kernel/lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 syzkaller/managers/linux-4-14/kernel/mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 syzkaller/managers/linux-4-14/kernel/mm/kasan/report.c:351 kasan_report syzkaller/managers/linux-4-14/kernel/mm/kasan/report.c:409 [inline] __asan_report_load1_noabort+0x68/0x70 syzkaller/managers/linux-4-14/kernel/mm/kasan/report.c:427 __fb_pad_aligned_buffer syzkaller/managers/linux-4-14/kernel/./include/linux/fb.h:663 [inline] bit_putcs_aligned syzkaller/managers/linux-4-14/kernel/drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xab7/0xc30 syzkaller/managers/linux-4-14/kernel/drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x2fe/0x480 syzkaller/managers/linux-4-14/kernel/drivers/video/fbdev/core/fbcon.c:1247 con_flush syzkaller/managers/linux-4-14/kernel/drivers/tty/vt/vt.c:2206 [inline] do_con_write+0xaf6/0x19b0 syzkaller/managers/linux-4-14/kernel/drivers/tty/vt/vt.c:2456 con_write+0x21/0xa0 syzkaller/managers/linux-4-14/kernel/drivers/tty/vt/vt.c:2805 process_output_block syzkaller/managers/linux-4-14/kernel/drivers/tty/n_tty.c:595 [inline] n_tty_write+0x352/0xda0 syzkaller/managers/linux-4-14/kernel/drivers/tty/n_tty.c:2333 do_tty_write syzkaller/managers/linux-4-14/kernel/drivers/tty/tty_io.c:959 [inline] tty_write+0x410/0x740 syzkaller/managers/linux-4-14/kernel/drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:480 vfs_write+0x17f/0x4d0 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:544 SYSC_write syzkaller/managers/linux-4-14/kernel/fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 syzkaller/managers/linux-4-14/kernel/fs/read_write.c:582 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f1c0ec53970 RSP: 002b:00007ffc6454c518 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f1c0ec53970 RDX: 0000000000000001 RSI: 00007f1c0ef12683 RDI: 0000000000000001 RBP: 00007f1c0ef12683 R08: 00007f1c0ef13760 R09: 00007f1c0f135500 R10: 0000000000000097 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000001 R14: 00007f1c0ef12600 R15: 0000000000000001 Allocated by task 10650: save_stack syzkaller/managers/linux-4-14/kernel/mm/kasan/kasan.c:447 [inline] set_track syzkaller/managers/linux-4-14/kernel/mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 syzkaller/managers/linux-4-14/kernel/mm/kasan/kasan.c:551 __do_kmalloc syzkaller/managers/linux-4-14/kernel/mm/slab.c:3720 [inline] __kmalloc+0x15a/0x400 syzkaller/managers/linux-4-14/kernel/mm/slab.c:3729 kmalloc syzkaller/managers/linux-4-14/kernel/./include/linux/slab.h:493 [inline] fbcon_set_font+0x2fb/0x7c0 syzkaller/managers/linux-4-14/kernel/drivers/video/fbdev/core/fbcon.c:2456 con_font_set syzkaller/managers/linux-4-14/kernel/drivers/tty/vt/vt.c:4190 [inline] con_font_op+0x9e8/0xdb0 syzkaller/managers/linux-4-14/kernel/drivers/tty/vt/vt.c:4234 vt_ioctl+0xd5d/0x1d50 syzkaller/managers/linux-4-14/kernel/drivers/tty/vt/vt_ioctl.c:938 tty_ioctl+0x50f/0x13c0 syzkaller/managers/linux-4-14/kernel/drivers/tty/tty_io.c:2661 vfs_ioctl syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:46 [inline] file_ioctl syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:684 SYSC_ioctl syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 syzkaller/managers/linux-4-14/kernel/fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 7977: save_stack syzkaller/managers/linux-4-14/kernel/mm/kasan/kasan.c:447 [inline] set_track syzkaller/managers/linux-4-14/kernel/mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 syzkaller/managers/linux-4-14/kernel/mm/kasan/kasan.c:524 __cache_free syzkaller/managers/linux-4-14/kernel/mm/slab.c:3496 [inline] kfree+0xc9/0x250 syzkaller/managers/linux-4-14/kernel/mm/slab.c:3815 skb_free_head syzkaller/managers/linux-4-14/kernel/net/core/skbuff.c:563 [inline] skb_release_data+0x5f6/0x820 syzkaller/managers/linux-4-14/kernel/net/core/skbuff.c:583 skb_release_all syzkaller/managers/linux-4-14/kernel/net/core/skbuff.c:640 [inline] __kfree_skb+0x46/0x60 syzkaller/managers/linux-4-14/kernel/net/core/skbuff.c:654 tcp_data_queue+0x1883/0x3aa0 syzkaller/managers/linux-4-14/kernel/net/ipv4/tcp_input.c:4684 tcp_rcv_established+0x696/0x1810 syzkaller/managers/linux-4-14/kernel/net/ipv4/tcp_input.c:5579 tcp_v4_do_rcv+0x541/0x7d0 syzkaller/managers/linux-4-14/kernel/net/ipv4/tcp_ipv4.c:1476 tcp_v4_rcv+0x275c/0x3560 syzkaller/managers/linux-4-14/kernel/net/ipv4/tcp_ipv4.c:1750 ip_local_deliver_finish+0x3f2/0xab0 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_input.c:216 NF_HOOK syzkaller/managers/linux-4-14/kernel/./include/linux/netfilter.h:250 [inline] ip_local_deliver+0x167/0x460 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_input.c:257 dst_input syzkaller/managers/linux-4-14/kernel/./include/net/dst.h:476 [inline] ip_rcv_finish+0x6e3/0x19f0 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_input.c:396 NF_HOOK syzkaller/managers/linux-4-14/kernel/./include/linux/netfilter.h:250 [inline] ip_rcv+0x8a7/0xf10 syzkaller/managers/linux-4-14/kernel/net/ipv4/ip_input.c:493 __netif_receive_skb_core+0x15ee/0x2a30 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:4474 __netif_receive_skb+0x27/0x1a0 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:4512 netif_receive_skb_internal+0xd7/0x580 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:4585 napi_skb_finish syzkaller/managers/linux-4-14/kernel/net/core/dev.c:4946 [inline] napi_gro_receive+0x2e2/0x400 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:4977 receive_buf+0x5ef/0x4810 syzkaller/managers/linux-4-14/kernel/drivers/net/virtio_net.c:852 virtnet_receive syzkaller/managers/linux-4-14/kernel/drivers/net/virtio_net.c:1098 [inline] virtnet_poll+0x4b7/0x960 syzkaller/managers/linux-4-14/kernel/drivers/net/virtio_net.c:1189 napi_poll syzkaller/managers/linux-4-14/kernel/net/core/dev.c:5596 [inline] net_rx_action+0x466/0xfd0 syzkaller/managers/linux-4-14/kernel/net/core/dev.c:5662 __do_softirq+0x24d/0x9ff syzkaller/managers/linux-4-14/kernel/kernel/softirq.c:288 The buggy address belongs to the object at ffff88809c835a40 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 424 bytes inside of 512-byte region [ffff88809c835a40, ffff88809c835c40) The buggy address belongs to the page: page:ffffea0002720d40 count:1 mapcount:0 mapping:ffff88809c835040 index:0xffff88809c835040 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff88809c835040 ffff88809c835040 0000000100000004 raw: ffffea00025f5ce0 ffffea0002c17120 ffff88813fe80940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809c835a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88809c835b00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc >ffff88809c835b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88809c835c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809c835c80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================