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BUG: KASAN: slab-out-of-bounds in rxrpc_send_keepalive+0x8a2/0x940 net/rxrpc/output.c:634
Read of size 8 at addr ffff888036754958 by task kworker/1:0/24421

CPU: 1 PID: 24421 Comm: kworker/1:0 Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: krxrpcd rxrpc_peer_keepalive_worker
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351
 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482
 kasan_report+0x12/0x17 mm/kasan/common.c:618
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 rxrpc_send_keepalive+0x8a2/0x940 net/rxrpc/output.c:634
 rxrpc_peer_keepalive_dispatch net/rxrpc/peer_event.c:369 [inline]
 rxrpc_peer_keepalive_worker+0x7be/0xd02 net/rxrpc/peer_event.c:430
 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 12435:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:493 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:466
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:507
 __do_kmalloc_node mm/slab.c:3615 [inline]
 __kmalloc_node+0x4e/0x70 mm/slab.c:3622
 kmalloc_node include/linux/slab.h:595 [inline]
 kvmalloc_node+0x68/0x100 mm/util.c:459
 kvmalloc include/linux/mm.h:670 [inline]
 seq_buf_alloc fs/seq_file.c:32 [inline]
 seq_read+0x817/0x1110 fs/seq_file.c:204
 kernfs_fop_read+0xed/0x560 fs/kernfs/file.c:251
 __vfs_read+0x8a/0x110 fs/read_write.c:425
 vfs_read+0x1f0/0x440 fs/read_write.c:461
 ksys_read+0x14f/0x290 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x73/0xb0 fs/read_write.c:595
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 12435:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:455
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:463
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3756
 kvfree+0x61/0x70 mm/util.c:488
 seq_release+0x54/0x80 fs/seq_file.c:360
 kernfs_fop_release+0xf7/0x1a0 fs/kernfs/file.c:780
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888036754ec0
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1384 bytes to the left of
 4096-byte region [ffff888036754ec0, ffff888036755ec0)
The buggy address belongs to the page:
page:ffffea0000d9d500 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea0000591f08 ffffea00025dd588 ffff8880aa402000
raw: 0000000000000000 ffff888036754ec0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888036754800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888036754880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888036754900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                    ^
 ffff888036754980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888036754a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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