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BUG: KASAN: slab-out-of-bounds in sctp_setsockopt_delayed_ack net/sctp/socket.c:2773 [inline]
BUG: KASAN: slab-out-of-bounds in sctp_setsockopt net/sctp/socket.c:4499 [inline]
BUG: KASAN: slab-out-of-bounds in sctp_setsockopt+0x91b5/0x95e0 net/sctp/socket.c:4431
Write of size 4 at addr ffff88809c569e48 by task syz-executor.4/6013

CPU: 0 PID: 6013 Comm: syz-executor.4 Not tainted 5.8.0-rc4-syzkaller #0
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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 sctp_setsockopt_delayed_ack net/sctp/socket.c:2773 [inline]
 sctp_setsockopt net/sctp/socket.c:4499 [inline]
 sctp_setsockopt+0x91b5/0x95e0 net/sctp/socket.c:4431
 __sys_setsockopt+0x337/0x6a0 net/socket.c:2137
 __do_sys_setsockopt net/socket.c:2153 [inline]
 __se_sys_setsockopt net/socket.c:2150 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2150
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1f9
Code: Bad RIP value.
RSP: 002b:00007f7f0f298c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 000000000002e900 RCX: 000000000045c1f9
RDX: 0000000000000010 RSI: 0000000000000084 RDI: 0000000000000006
RBP: 000000000078bf50 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000020000340 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffd38fb959f R14: 00007f7f0f2999c0 R15: 000000000078bf0c

Allocated by task 6013:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc_track_caller+0x178/0x330 mm/slab.c:3671
 memdup_user+0x22/0xd0 mm/util.c:172
 sctp_setsockopt net/sctp/socket.c:4452 [inline]
 sctp_setsockopt+0x17a/0x95e0 net/sctp/socket.c:4431
 __sys_setsockopt+0x337/0x6a0 net/socket.c:2137
 __do_sys_setsockopt net/socket.c:2153 [inline]
 __se_sys_setsockopt net/socket.c:2150 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2150
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 5650:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x103/0x2c0 mm/slab.c:3757
 kvfree+0x42/0x50 mm/util.c:603
 __vunmap+0x88a/0xac0 mm/vmalloc.c:2306
 __vfree mm/vmalloc.c:2350 [inline]
 vfree+0x88/0x140 mm/vmalloc.c:2380
 netlink_skb_destructor+0xc2/0x210 net/netlink/af_netlink.c:367
 skb_release_head_state+0x9f/0x250 net/core/skbuff.c:651
 skb_release_all net/core/skbuff.c:662 [inline]
 __kfree_skb net/core/skbuff.c:678 [inline]
 consume_skb net/core/skbuff.c:837 [inline]
 consume_skb+0x89/0x160 net/core/skbuff.c:831
 netlink_unicast_kernel net/netlink/af_netlink.c:1305 [inline]
 netlink_unicast+0x53b/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 sock_no_sendpage+0xee/0x130 net/core/sock.c:2821
 kernel_sendpage net/socket.c:3653 [inline]
 sock_sendpage+0xe5/0x140 net/socket.c:944
 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:448
 splice_from_pipe_feed fs/splice.c:502 [inline]
 __splice_from_pipe+0x3dc/0x830 fs/splice.c:626
 splice_from_pipe fs/splice.c:661 [inline]
 generic_splice_sendpage+0xd4/0x140 fs/splice.c:834
 do_splice_from fs/splice.c:846 [inline]
 direct_splice_actor+0x171/0x2f0 fs/splice.c:1016
 splice_direct_to_actor+0x38c/0x980 fs/splice.c:971
 do_splice_direct+0x1b3/0x280 fs/splice.c:1059
 do_sendfile+0x559/0xc30 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1587
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88809c569e40
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff88809c569e40, ffff88809c569e60)
The buggy address belongs to the page:
page:ffffea0002715a40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88809c569fc1
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea000278c448 ffffea000278cf48 ffff8880aa0001c0
raw: ffff88809c569fc1 ffff88809c569000 000000010000003e 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809c569d00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff88809c569d80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff88809c569e00: 00 00 00 02 fc fc fc fc 00 fc fc fc fc fc fc fc
                                              ^
 ffff88809c569e80: fb fb fb fb fc fc fc fc 05 fc fc fc fc fc fc fc
 ffff88809c569f00: 00 01 fc fc fc fc fc fc 06 fc fc fc fc fc fc fc
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