netlink: 60 bytes leftover after parsing attributes in process `syz-executor5'.
==================================================================
BUG: KASAN: use-after-free in ax25_fillin_cb_from_dev net/ax25/af_ax25.c:450 [inline]
BUG: KASAN: use-after-free in ax25_fillin_cb+0x6d5/0x810 net/ax25/af_ax25.c:477
Read of size 4 at addr ffff8881912a7238 by task syz-executor2/14680

CPU: 1 PID: 14680 Comm: syz-executor2 Not tainted 4.20.0-rc7+ #248
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d3/0x2c6 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 ax25_fillin_cb_from_dev net/ax25/af_ax25.c:450 [inline]
 ax25_fillin_cb+0x6d5/0x810 net/ax25/af_ax25.c:477
 ax25_setsockopt+0x92a/0xa20 net/ax25/af_ax25.c:663
 __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902
 __do_sys_setsockopt net/socket.c:1913 [inline]
 __se_sys_setsockopt net/socket.c:1910 [inline]
 __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457759
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5963d86c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457759
RDX: 0000000000000019 RSI: 0000000000000101 RDI: 0000000000000005
RBP: 000000000073bf00 R08: 0000000000000010 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00007f5963d876d4
R13: 00000000004cb2d8 R14: 00000000004d8910 R15: 00000000ffffffff

Allocated by task 11771:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc mm/slab.c:3722 [inline]
 __kmalloc+0x15b/0x770 mm/slab.c:3731
 kmalloc_array include/linux/slab.h:669 [inline]
 kcalloc include/linux/slab.h:680 [inline]
 ext4_find_extent+0x757/0x9b0 fs/ext4/extents.c:888
 ext4_ext_map_blocks+0x2ad/0x6180 fs/ext4/extents.c:4223
 ext4_map_blocks+0x8f7/0x1b60 fs/ext4/inode.c:636
 ext4_alloc_file_blocks+0x319/0xaf0 fs/ext4/extents.c:4593
 ext4_fallocate+0xa33/0x2300 fs/ext4/extents.c:4878
 vfs_fallocate+0x4b4/0x940 fs/open.c:308
 ioctl_preallocate+0x1e8/0x300 fs/ioctl.c:490
 file_ioctl fs/ioctl.c:506 [inline]
 do_vfs_ioctl+0x148f/0x1790 fs/ioctl.c:696
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 11771:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3817
 ext4_ext_map_blocks+0xe26/0x6180 fs/ext4/extents.c:4506
 ext4_map_blocks+0x8f7/0x1b60 fs/ext4/inode.c:636
 ext4_alloc_file_blocks+0x319/0xaf0 fs/ext4/extents.c:4593
 ext4_fallocate+0xa33/0x2300 fs/ext4/extents.c:4878
 vfs_fallocate+0x4b4/0x940 fs/open.c:308
 ioctl_preallocate+0x1e8/0x300 fs/ioctl.c:490
 file_ioctl fs/ioctl.c:506 [inline]
 do_vfs_ioctl+0x148f/0x1790 fs/ioctl.c:696
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8881912a7200
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 56 bytes inside of
 192-byte region [ffff8881912a7200, ffff8881912a72c0)
The buggy address belongs to the page:
page:ffffea000644a9c0 count:1 mapcount:0 mapping:ffff8881da800040 index:0xffff8881912a7f00
flags: 0x2fffc0000000200(slab)
raw: 02fffc0000000200 ffffea000748bbc8 ffffea0006146808 ffff8881da800040
raw: ffff8881912a7f00 ffff8881912a7000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881912a7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881912a7180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8881912a7200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff8881912a7280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8881912a7300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================