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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 ffff88809004b490 by task syz-executor.2/14831

CPU: 1 PID: 14831 Comm: syz-executor.2 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:00007ff244eb5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f3d40 RCX: 000000000045cba9
RDX: 0000000020000080 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000681 R14: 00000000004c9900 R15: 00007ff244eb66d4

Allocated by task 14761:
 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 6353:
 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
 kvfree+0x45/0x50 mm/util.c:416
 __do_replace+0x3f0/0x570 net/ipv4/netfilter/ip_tables.c:1088
 do_replace net/ipv4/netfilter/ip_tables.c:1142 [inline]
 do_ipt_set_ctl+0x255/0x39d net/ipv4/netfilter/ip_tables.c:1674
 nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
 nf_setsockopt+0x5f/0xb0 net/netfilter/nf_sockopt.c:115
 ip_setsockopt net/ipv4/ip_sockglue.c:1255 [inline]
 ip_setsockopt+0x94/0xb0 net/ipv4/ip_sockglue.c:1240
 tcp_setsockopt net/ipv4/tcp.c:2828 [inline]
 tcp_setsockopt+0x7b/0xc0 net/ipv4/tcp.c:2822
 SYSC_setsockopt net/socket.c:1865 [inline]
 SyS_setsockopt+0x110/0x1e0 net/socket.c:1844
 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 ffff88809004b200
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 656 bytes inside of
 1024-byte region [ffff88809004b200, ffff88809004b600)
The buggy address belongs to the page:
page:ffffea0002401280 count:1 mapcount:0 mapping:ffff88809004a000 index:0xffff88809004a480 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff88809004a000 ffff88809004a480 0000000100000004
raw: ffffea000127eaa0 ffffea0002289320 ffff8880aa800ac0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809004b380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809004b400: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88809004b480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88809004b500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809004b580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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