bpfilter: read fail -512
==================================================================
BUG: KASAN: use-after-free in io_is_direct include/linux/fs.h:3203 [inline]
BUG: KASAN: use-after-free in iocb_flags include/linux/fs.h:3230 [inline]
BUG: KASAN: use-after-free in init_sync_kiocb include/linux/fs.h:1941 [inline]
BUG: KASAN: use-after-free in new_sync_write fs/read_write.c:470 [inline]
BUG: KASAN: use-after-free in __vfs_write+0x929/0x960 fs/read_write.c:487
Read of size 8 at addr ffff8801d1c18d28 by task syz-executor2/4574
CPU: 1 PID: 4574 Comm: syz-executor2 Not tainted 4.17.0+ #83
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+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
io_is_direct include/linux/fs.h:3203 [inline]
iocb_flags include/linux/fs.h:3230 [inline]
init_sync_kiocb include/linux/fs.h:1941 [inline]
new_sync_write fs/read_write.c:470 [inline]
__vfs_write+0x929/0x960 fs/read_write.c:487
__kernel_write+0x10c/0x380 fs/read_write.c:506
__bpfilter_process_sockopt+0x1d8/0x35b net/bpfilter/bpfilter_kern.c:66
bpfilter_mbox_request+0x4d/0xb0 net/ipv4/bpfilter/sockopt.c:25
bpfilter_ip_get_sockopt+0x6b/0x90 net/ipv4/bpfilter/sockopt.c:42
ip_getsockopt+0x238/0x2a0 net/ipv4/ip_sockglue.c:1563
tcp_getsockopt+0x93/0xe0 net/ipv4/tcp.c:3532
sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:3012
__sys_getsockopt+0x1a5/0x370 net/socket.c:1972
__do_sys_getsockopt net/socket.c:1983 [inline]
__se_sys_getsockopt net/socket.c:1980 [inline]
__x64_sys_getsockopt+0xbe/0x150 net/socket.c:1980
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4584ea
Code: b8 34 01 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 1d 8f fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 fa 8e fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:0000000000a3e328 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000a3e350 RCX: 00000000004584ea
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000013
RBP: 0000000000705f20 R08: 0000000000a3e34c R09: 0000000000004000
R10: 0000000000a3e350 R11: 0000000000000246 R12: 0000000000000013
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000704420
Allocated by task 2223:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
alloc_inode+0xb2/0x190 fs/inode.c:212
new_inode_pseudo+0x69/0x1a0 fs/inode.c:895
get_pipe_inode fs/pipe.c:707 [inline]
create_pipe_files+0x90/0x940 fs/pipe.c:748
umh_pipe_setup+0xac/0x430 kernel/umh.c:431
call_usermodehelper_exec_async+0x3c0/0x9e0 kernel/umh.c:93
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Freed by task 6988:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
free_inode_nonrcu+0x1c/0x20 fs/inode.c:230
destroy_inode+0x151/0x1f0 fs/inode.c:267
evict+0x5cd/0x960 fs/inode.c:575
iput_final fs/inode.c:1506 [inline]
iput+0x62d/0xa80 fs/inode.c:1532
dentry_unlink_inode+0x49a/0x620 fs/dcache.c:376
__dentry_kill+0x444/0x790 fs/dcache.c:568
dentry_kill+0xc9/0x5a0 fs/dcache.c:687
dput.part.26+0x65a/0x780 fs/dcache.c:848
dput+0x15/0x20 fs/dcache.c:830
__fput+0x558/0x890 fs/file_table.c:227
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0x1e4/0x290 kernel/task_work.c:113
get_signal+0x153e/0x1960 kernel/signal.c:2308
do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810
exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8801d1c18b20
which belongs to the cache inode_cache of size 944
The buggy address is located 520 bytes inside of
944-byte region [ffff8801d1c18b20, ffff8801d1c18ed0)
The buggy address belongs to the page:
page:ffffea0007470600 count:1 mapcount:0 mapping:ffff8801d1c182c0 index:0xffff8801d1c18ffd
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d1c182c0 ffff8801d1c18ffd 0000000100000003
raw: ffffea00074702a0 ffffea0007470da0 ffff8801da986ac0 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8801d1c18c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801d1c18c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801d1c18d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8801d1c18d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801d1c18e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================