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BUG: KASAN: use-after-free in tipc_recvmsg+0xf77/0xf90 net/tipc/socket.c:1979
Read of size 4 at addr ffff888021e662c0 by task syz-executor.2/15720

CPU: 0 PID: 15720 Comm: syz-executor.2 Not tainted 5.14.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
 tipc_recvmsg+0xf77/0xf90 net/tipc/socket.c:1979
 sock_recvmsg_nosec net/socket.c:943 [inline]
 sock_recvmsg net/socket.c:961 [inline]
 sock_recvmsg net/socket.c:957 [inline]
 ____sys_recvmsg+0x2c4/0x600 net/socket.c:2606
 ___sys_recvmsg+0x127/0x200 net/socket.c:2648
 __sys_recvmsg+0xe2/0x1a0 net/socket.c:2678
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff194560188 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000000000000 RSI: 0000000020000d40 RDI: 0000000000000003
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc6e19784f R14: 00007ff194560300 R15: 0000000000022000

Allocated by task 15727:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x84/0xa0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slub.c:2956 [inline]
 kmem_cache_alloc_node+0x266/0x3e0 mm/slub.c:2992
 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414
 alloc_skb_fclone include/linux/skbuff.h:1162 [inline]
 tipc_buf_acquire+0x25/0xe0 net/tipc/msg.c:72
 tipc_msg_reverse+0x1ee/0x970 net/tipc/msg.c:647
 tipc_sk_respond+0x1f0/0x560 net/tipc/socket.c:291
 __tipc_shutdown+0x9c5/0xe90 net/tipc/socket.c:588
 tipc_release+0x13f/0x1a80 net/tipc/socket.c:640
 __sock_release+0xcd/0x280 net/socket.c:648
 sock_close+0x18/0x20 net/socket.c:1295
 __fput+0x288/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 15720:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1625 [inline]
 slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1650
 slab_free mm/slub.c:3210 [inline]
 kmem_cache_free+0x8e/0x5a0 mm/slub.c:3226
 kfree_skbmem+0x166/0x1b0 net/core/skbuff.c:720
 __kfree_skb net/core/skbuff.c:756 [inline]
 kfree_skb net/core/skbuff.c:773 [inline]
 kfree_skb+0x140/0x3f0 net/core/skbuff.c:767
 tipc_recvmsg+0x70d/0xf90 net/tipc/socket.c:1977
 sock_recvmsg_nosec net/socket.c:943 [inline]
 sock_recvmsg net/socket.c:961 [inline]
 sock_recvmsg net/socket.c:957 [inline]
 ____sys_recvmsg+0x2c4/0x600 net/socket.c:2606
 ___sys_recvmsg+0x127/0x200 net/socket.c:2648
 __sys_recvmsg+0xe2/0x1a0 net/socket.c:2678
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888021e66280
 which belongs to the cache skbuff_fclone_cache of size 472
The buggy address is located 64 bytes inside of
 472-byte region [ffff888021e66280, ffff888021e66458)
The buggy address belongs to the page:
page:ffffea0000879980 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21e66
head:ffffea0000879980 order:1 compound_mapcount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0000a7aa00 0000000900000009 ffff8881445b1280
raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 11544, ts 201496162213, free_ts 201413172136
 prep_new_page mm/page_alloc.c:2433 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4166
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5388
 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244
 alloc_slab_page mm/slub.c:1688 [inline]
 allocate_slab+0x32e/0x4b0 mm/slub.c:1828
 new_slab mm/slub.c:1891 [inline]
 new_slab_objects mm/slub.c:2637 [inline]
 ___slab_alloc+0x4ba/0x820 mm/slub.c:2800
 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2840
 slab_alloc_node mm/slub.c:2922 [inline]
 kmem_cache_alloc_node+0x12c/0x3e0 mm/slub.c:2992
 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414
 alloc_skb_fclone include/linux/skbuff.h:1162 [inline]
 tipc_buf_acquire+0x25/0xe0 net/tipc/msg.c:72
 tipc_msg_build+0xf7/0x10a0 net/tipc/msg.c:386
 __tipc_sendmsg+0xab6/0x1770 net/tipc/socket.c:1501
 tipc_sendmsg+0x4c/0x70 net/tipc/socket.c:1401
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:723
 sock_no_sendpage+0xf3/0x130 net/core/sock.c:2959
 kernel_sendpage.part.0+0x1a0/0x340 net/socket.c:3511
 kernel_sendpage net/socket.c:3508 [inline]
 sock_sendpage+0xe5/0x140 net/socket.c:1002
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1343 [inline]
 free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1394
 free_unref_page_prepare mm/page_alloc.c:3329 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3408
 unfreeze_partials+0x17c/0x1d0 mm/slub.c:2418
 put_cpu_partial+0x13d/0x230 mm/slub.c:2454
 qlink_free mm/kasan/quarantine.c:146 [inline]
 qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
 __kasan_slab_alloc+0x8e/0xa0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc_node mm/slub.c:2956 [inline]
 slab_alloc mm/slub.c:2964 [inline]
 kmem_cache_alloc+0x285/0x4a0 mm/slub.c:2969
 kmem_cache_zalloc include/linux/slab.h:711 [inline]
 alloc_buffer_head+0x20/0x140 fs/buffer.c:3332
 alloc_page_buffers+0x28a/0x770 fs/buffer.c:832
 create_empty_buffers+0x2c/0x840 fs/buffer.c:1556
 ext4_block_write_begin+0xcf2/0x1110 fs/ext4/inode.c:1059
 ext4_da_write_begin+0x3d8/0x11c0 fs/ext4/inode.c:3015
 generic_perform_write+0x202/0x500 mm/filemap.c:3656
 ext4_buffered_write_iter+0x244/0x4d0 fs/ext4/file.c:269
 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:680

Memory state around the buggy address:
 ffff888021e66180: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
 ffff888021e66200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888021e66280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888021e66300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888021e66380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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