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BUG: KASAN: use-after-free in rxrpc_send_keepalive+0x8a2/0x940 net/rxrpc/output.c:634
Read of size 8 at addr ffff888094394818 by task kworker/1:0/17

CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.4.0-rc3+ #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.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:634
 __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 8826:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:510 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x163/0x770 mm/slab.c:3664
 kmalloc include/linux/slab.h:561 [inline]
 tomoyo_realpath_from_path+0xcd/0x7b0 security/tomoyo/realpath.c:277
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path2_perm+0x344/0x670 security/tomoyo/file.c:923
 tomoyo_path_rename+0xee/0x150 security/tomoyo/tomoyo.c:285
 security_path_rename+0x20c/0x300 security/security.c:1079
 do_renameat2+0x7b8/0xc40 fs/namei.c:4615
 __do_sys_rename fs/namei.c:4665 [inline]
 __se_sys_rename fs/namei.c:4663 [inline]
 __x64_sys_rename+0x61/0x80 fs/namei.c:4663
 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8826:
 save_stack+0x23/0x90 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3756
 tomoyo_realpath_from_path+0x1de/0x7b0 security/tomoyo/realpath.c:319
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path2_perm+0x344/0x670 security/tomoyo/file.c:923
 tomoyo_path_rename+0xee/0x150 security/tomoyo/tomoyo.c:285
 security_path_rename+0x20c/0x300 security/security.c:1079
 do_renameat2+0x7b8/0xc40 fs/namei.c:4615
 __do_sys_rename fs/namei.c:4665 [inline]
 __se_sys_rename fs/namei.c:4663 [inline]
 __x64_sys_rename+0x61/0x80 fs/namei.c:4663
 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888094394000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2072 bytes inside of
 4096-byte region [ffff888094394000, ffff888094395000)
The buggy address belongs to the page:
page:ffffea000250e500 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea0002504908 ffffea000290bc88 ffff8880aa402000
raw: 0000000000000000 ffff888094394000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888094394700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888094394780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888094394800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888094394880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888094394900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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