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netlink: 8 bytes leftover after parsing attributes in process `syz-executor.0'.
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline]
BUG: KASAN: use-after-free in check_net include/net/net_namespace.h:254 [inline]
BUG: KASAN: use-after-free in rds_destroy_pending net/rds/rds.h:951 [inline]
BUG: KASAN: use-after-free in rds_cong_queue_updates+0x209/0x4d0 net/rds/cong.c:229
Read of size 4 at addr ffff8880866400c4 by task kworker/u4:3/11973

CPU: 1 PID: 11973 Comm: kworker/u4:3 Not tainted 5.0.0-rc8+ #96
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krdsd rds_send_worker
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 kasan_check_read+0x11/0x20 mm/kasan/common.c:100
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 refcount_read include/linux/refcount.h:43 [inline]
 check_net include/net/net_namespace.h:254 [inline]
 rds_destroy_pending net/rds/rds.h:951 [inline]
 rds_cong_queue_updates+0x209/0x4d0 net/rds/cong.c:229
 rds_recv_rcvbuf_delta.part.0+0x34f/0x3f0 net/rds/recv.c:118
 rds_recv_rcvbuf_delta net/rds/recv.c:379 [inline]
 rds_recv_incoming+0x789/0x11f0 net/rds/recv.c:379
 rds_loop_xmit+0xf3/0x2a0 net/rds/loop.c:96
 rds_send_xmit+0x1113/0x2560 net/rds/send.c:355
 rds_send_worker+0x90/0x290 net/rds/threads.c:200
 process_one_work+0x98e/0x1790 kernel/workqueue.c:2173
 worker_thread+0x98/0xe40 kernel/workqueue.c:2319
 kthread+0x357/0x430 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

The buggy address belongs to the page:
page:ffffea0002199000 count:0 mapcount:-128 mapping:0000000000000000 index:0xffff888086640000
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 ffffea0002255d08 ffffea0002a5d508 0000000000000000
raw: ffff888086640000 0000000000000002 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808663ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888086640000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888086640080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff888086640100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888086640180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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