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BUG: KASAN: use-after-free in ip_check_mc_rcu+0x604/0x660 net/ipv4/igmp.c:2716
Read of size 4 at addr ffff88801862fc98 by task syz-executor.4/18841

CPU: 0 PID: 18841 Comm: syz-executor.4 Not tainted 5.12.0-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/0x2f8 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+0x604/0x660 net/ipv4/igmp.c:2716
 __mkroute_output net/ipv4/route.c:2510 [inline]
 ip_route_output_key_hash_rcu+0x1959/0x2ce0 net/ipv4/route.c:2789
 ip_route_output_key_hash+0x1a4/0x2f0 net/ipv4/route.c:2617
 __ip_route_output_key include/net/route.h:126 [inline]
 ip_route_output_flow+0x23/0x150 net/ipv4/route.c:2849
 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:00007fdb12b8d188 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: 00007ffe8a4bd73f R14: 00007fdb12b8d300 R15: 0000000000022000

Allocated by task 18841:
 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+0x9b/0xd0 mm/kasan/common.c:516
 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 18838:
 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+0xfb/0x130 mm/kasan/common.c:368
 kasan_slab_free include/linux/kasan.h:212 [inline]
 slab_free_hook mm/slub.c:1581 [inline]
 slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1606
 slab_free mm/slub.c:3166 [inline]
 kfree+0xe5/0x7f0 mm/slub.c:4225
 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 ffff88801862fc80
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes inside of
 32-byte region [ffff88801862fc80, ffff88801862fca0)
The buggy address belongs to the page:
page:ffffea0000618bc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801862fc00 pfn:0x1862f
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00004d6600 0000000400000004 ffff888011041500
raw: ffff88801862fc00 000000008040003f 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 2786167254, free_ts 2733762782
 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_page_interleave+0x1e/0x1d0 mm/mempolicy.c:2147
 alloc_pages+0x238/0x2a0 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:1644 [inline]
 allocate_slab+0x2c5/0x4c0 mm/slub.c:1784
 new_slab mm/slub.c:1847 [inline]
 new_slab_objects mm/slub.c:2593 [inline]
 ___slab_alloc+0x44c/0x7a0 mm/slub.c:2756
 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2796
 slab_alloc_node mm/slub.c:2878 [inline]
 slab_alloc mm/slub.c:2920 [inline]
 __kmalloc_track_caller+0x301/0x320 mm/slub.c:4573
 __do_krealloc mm/slab_common.c:1165 [inline]
 krealloc+0x87/0xf0 mm/slab_common.c:1198
 add_sysfs_param+0x152/0x960 kernel/params.c:642
 kernel_add_sysfs_param kernel/params.c:794 [inline]
 param_sysfs_builtin kernel/params.c:833 [inline]
 param_sysfs_init+0x359/0x498 kernel/params.c:952
 do_one_initcall+0x103/0x650 init/main.c:1249
 do_initcall_level init/main.c:1322 [inline]
 do_initcalls init/main.c:1338 [inline]
 do_basic_setup init/main.c:1358 [inline]
 kernel_init_freeable+0x643/0x6cc init/main.c:1560
 kernel_init+0xd/0x1b8 init/main.c:1447
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1298 [inline]
 free_pcp_prepare+0x223/0x300 mm/page_alloc.c:1342
 free_unref_page_prepare mm/page_alloc.c:3250 [inline]
 free_unref_page+0x12/0x1d0 mm/page_alloc.c:3298
 __vunmap+0x783/0xb60 mm/vmalloc.c:2566
 free_work+0x58/0x70 mm/vmalloc.c:80
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Memory state around the buggy address:
 ffff88801862fb80: fa fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
 ffff88801862fc00: fb fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
>ffff88801862fc80: fa fb fb fb fc fc fc fc 00 00 00 04 fc fc fc fc
                            ^
 ffff88801862fd00: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff88801862fd80: fa fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
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