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BUG: KASAN: use-after-free in ip_check_mc_rcu+0x64a/0x660 net/ipv4/igmp.c:2721
Read of size 8 at addr ffff8880196f4e88 by task syz-executor.5/15178

CPU: 1 PID: 15178 Comm: syz-executor.5 Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436
 ip_check_mc_rcu+0x64a/0x660 net/ipv4/igmp.c:2721
 __mkroute_output net/ipv4/route.c:2387 [inline]
 ip_route_output_key_hash_rcu+0x1959/0x2ce0 net/ipv4/route.c:2666
 ip_route_output_key_hash+0x1a4/0x2f0 net/ipv4/route.c:2494
 __ip_route_output_key include/net/route.h:126 [inline]
 ip_route_output_flow+0x23/0x150 net/ipv4/route.c:2726
 udp_sendmsg+0x1a2f/0x2730 net/ipv4/udp.c:1206
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 ____sys_sendmsg+0x331/0x810 net/socket.c:2350
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404
 __sys_sendmmsg+0x195/0x470 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2516
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
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:00007f7d0bafa188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 000000000800001d RSI: 0000000020007fc0 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc0feff69f R14: 00007f7d0bafa300 R15: 0000000000022000

Allocated by task 15178:
 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:428 [inline]
 ____kasan_kmalloc mm/kasan/common.c:507 [inline]
 ____kasan_kmalloc mm/kasan/common.c:466 [inline]
 __kasan_kmalloc+0x98/0xc0 mm/kasan/common.c:516
 kasan_kmalloc include/linux/kasan.h:246 [inline]
 kmem_cache_alloc_trace+0x1fa/0x480 mm/slab.c:3575
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:686 [inline]
 ip_mc_add1_src net/ipv4/igmp.c:1971 [inline]
 ip_mc_add_src+0x7f8/0xdb0 net/ipv4/igmp.c:2095
 ip_mc_msfilter+0x899/0xb40 net/ipv4/igmp.c:2479
 do_ip_setsockopt net/ipv4/ip_sockglue.c:1255 [inline]
 ip_setsockopt+0x3272/0x3a40 net/ipv4/ip_sockglue.c:1423
 tcp_setsockopt+0x136/0x24a0 net/ipv4/tcp.c:3656
 __sys_setsockopt+0x2db/0x610 net/socket.c:2117
 __do_sys_setsockopt net/socket.c:2128 [inline]
 __se_sys_setsockopt net/socket.c:2125 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2125
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 15161:
 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:357
 ____kasan_slab_free mm/kasan/common.c:360 [inline]
 ____kasan_slab_free mm/kasan/common.c:325 [inline]
 __kasan_slab_free+0xcd/0x100 mm/kasan/common.c:368
 kasan_slab_free include/linux/kasan.h:212 [inline]
 __cache_free mm/slab.c:3445 [inline]
 kfree+0x106/0x2c0 mm/slab.c:3803
 ip_mc_del1_src+0x67d/0x800 net/ipv4/igmp.c:1884
 ip_mc_del_src.isra.0+0x3e1/0x960 net/ipv4/igmp.c:1925
 ip_mc_leave_src.isra.0+0x102/0x240 net/ipv4/igmp.c:2231
 ip_mc_drop_socket+0x11a/0x260 net/ipv4/igmp.c:2677
 inet_release+0x97/0x280 net/ipv4/af_inet.c:418
 __sock_release+0xcd/0x280 net/socket.c:599
 sock_close+0x18/0x20 net/socket.c:1258
 __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:174 [inline]
 exit_to_user_mode_prepare+0x272/0x280 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:57
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff8880196f4e80
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8880196f4e80, ffff8880196f4ea0)
The buggy address belongs to the page:
page:ffffea000065bd00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880196f4fc1 pfn:0x196f4
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000aa6e08 ffffea00005e7188 ffff888011040100
raw: ffff8880196f4fc1 ffff8880196f4000 000000010000003c 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_THISNODE), pid 2, ts 3158792910, free_ts 0
 prep_new_page mm/page_alloc.c:2358 [inline]
 get_page_from_freelist+0x1033/0x2b60 mm/page_alloc.c:3994
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5200
 __alloc_pages_node include/linux/gfp.h:549 [inline]
 kmem_getpages mm/slab.c:1377 [inline]
 cache_grow_begin+0x75/0x460 mm/slab.c:2593
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2965
 ____cache_alloc mm/slab.c:3048 [inline]
 ____cache_alloc mm/slab.c:3031 [inline]
 __do_cache_alloc mm/slab.c:3275 [inline]
 slab_alloc mm/slab.c:3316 [inline]
 __do_kmalloc mm/slab.c:3700 [inline]
 __kmalloc+0x3eb/0x4d0 mm/slab.c:3711
 kmalloc include/linux/slab.h:561 [inline]
 kzalloc include/linux/slab.h:686 [inline]
 lsm_task_alloc security/security.c:613 [inline]
 security_task_alloc+0x10b/0x250 security/security.c:1642
 copy_process+0x1ff0/0x7120 kernel/fork.c:2098
 kernel_clone+0xe7/0xab0 kernel/fork.c:2503
 kernel_thread+0xb5/0xf0 kernel/fork.c:2555
 create_kthread kernel/kthread.c:336 [inline]
 kthreadd+0x52a/0x790 kernel/kthread.c:679
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880196f4d80: fa fb fb fb fc fc fc fc 00 00 01 fc fc fc fc fc
 ffff8880196f4e00: 00 00 01 fc fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8880196f4e80: fa fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc
                      ^
 ffff8880196f4f00: 00 00 01 fc fc fc fc fc 06 fc fc fc fc fc fc fc
 ffff8880196f4f80: 06 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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