==================================================================
BUG: KASAN: use-after-free in ip_check_mc_rcu+0x546/0x600 net/ipv4/igmp.c:2721
Read of size 8 at addr ffff888037b29310 by task syz-executor.1/5902

CPU: 0 PID: 5902 Comm: syz-executor.1 Not tainted 5.14.0-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:88 [inline]
 dump_stack_lvl+0x1ae/0x29f lib/dump_stack.c:105
 print_address_description+0x66/0x3b0 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report+0x163/0x210 mm/kasan/report.c:436
 ip_check_mc_rcu+0x546/0x600 net/ipv4/igmp.c:2721
 __mkroute_output net/ipv4/route.c:2524 [inline]
 ip_route_output_key_hash_rcu+0xf3f/0x2570 net/ipv4/route.c:2803
 ip_route_output_key_hash+0x1b7/0x300 net/ipv4/route.c:2631
 __ip_route_output_key include/net/route.h:126 [inline]
 ip_route_output_flow+0x25/0x130 net/ipv4/route.c:2863
 udp_sendmsg+0x1cf1/0x3260 net/ipv4/udp.c:1219
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg net/socket.c:723 [inline]
 ____sys_sendmsg+0x5a2/0x900 net/socket.c:2392
 ___sys_sendmsg net/socket.c:2446 [inline]
 __sys_sendmmsg+0x500/0x790 net/socket.c:2532
 __do_sys_sendmmsg net/socket.c:2561 [inline]
 __se_sys_sendmmsg net/socket.c:2558 [inline]
 __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2558
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/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:00007f5da2142188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 000000000800001d RSI: 0000000020007fc0 RDI: 0000000000000004
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffd8fdad7bf R14: 00007f5da2142300 R15: 0000000000022000

Allocated by task 5902:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xc4/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 kmem_cache_alloc_trace+0x96/0x340 mm/slub.c:2983
 kmalloc include/linux/slab.h:591 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 ip_mc_add1_src net/ipv4/igmp.c:1972 [inline]
 ip_mc_add_src+0x766/0xd80 net/ipv4/igmp.c:2096
 ip_mc_msfilter+0x691/0xc50 net/ipv4/igmp.c:2480
 do_ip_setsockopt net/ipv4/ip_sockglue.c:1255 [inline]
 ip_setsockopt+0x3ea4/0x54a0 net/ipv4/ip_sockglue.c:1423
 __sys_setsockopt+0x552/0x980 net/socket.c:2159
 __do_sys_setsockopt net/socket.c:2170 [inline]
 __se_sys_setsockopt net/socket.c:2167 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2167
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 5897:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x3d/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0x109/0x150 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1625 [inline]
 slab_free_freelist_hook+0x1d8/0x290 mm/slub.c:1650
 slab_free mm/slub.c:3210 [inline]
 kfree+0xd0/0x1f0 mm/slub.c:4264
 ip_mc_del1_src+0x6ff/0x860 net/ipv4/igmp.c:1885
 ip_mc_del_src+0x636/0xa40 net/ipv4/igmp.c:1926
 ip_mc_leave_src+0x10b/0x200 net/ipv4/igmp.c:2232
 ip_mc_drop_socket+0x198/0x260 net/ipv4/igmp.c:2678
 inet_release+0x82/0x1f0 net/ipv4/af_inet.c:418
 __sock_release net/socket.c:648 [inline]
 sock_close+0xd8/0x260 net/socket.c:1300
 __fput+0x352/0x7b0 fs/file_table.c:280
 task_work_run+0x146/0x1c0 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+0x201/0x220 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302
 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888037b29300
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 16 bytes inside of
 32-byte region [ffff888037b29300, ffff888037b29320)
The buggy address belongs to the page:
page:ffffea0000deca40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x37b29
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0005169680 0000000e0000000e ffff888011041500
raw: 0000000000000000 0000000000400040 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 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 38529179559, free_ts 38464801844
 prep_new_page mm/page_alloc.c:2436 [inline]
 get_page_from_freelist+0x779/0xa30 mm/page_alloc.c:4169
 __alloc_pages+0x26c/0x5f0 mm/page_alloc.c:5391
 alloc_slab_page mm/slub.c:1688 [inline]
 allocate_slab+0xf1/0x540 mm/slub.c:1828
 new_slab mm/slub.c:1891 [inline]
 new_slab_objects mm/slub.c:2637 [inline]
 ___slab_alloc+0x1cf/0x350 mm/slub.c:2800
 __slab_alloc mm/slub.c:2840 [inline]
 slab_alloc_node mm/slub.c:2922 [inline]
 slab_alloc mm/slub.c:2964 [inline]
 __kmalloc+0x2e7/0x390 mm/slub.c:4108
 kmalloc include/linux/slab.h:596 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 tomoyo_encode2+0x25a/0x560 security/tomoyo/realpath.c:45
 tomoyo_encode security/tomoyo/realpath.c:80 [inline]
 tomoyo_realpath_from_path+0x5c3/0x610 security/tomoyo/realpath.c:288
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x201/0x650 security/tomoyo/file.c:822
 security_inode_getattr+0xc0/0x140 security/security.c:1332
 vfs_getattr fs/stat.c:139 [inline]
 vfs_statx+0x188/0x3d0 fs/stat.c:207
 vfs_fstatat fs/stat.c:225 [inline]
 vfs_lstat include/linux/fs.h:3386 [inline]
 __do_sys_newlstat fs/stat.c:380 [inline]
 __se_sys_newlstat+0xab/0x770 fs/stat.c:374
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1346 [inline]
 free_pcp_prepare+0xc29/0xd20 mm/page_alloc.c:1397
 free_unref_page_prepare mm/page_alloc.c:3332 [inline]
 free_unref_page_list+0x118/0xad0 mm/page_alloc.c:3448
 release_pages+0x18bb/0x1af0 mm/swap.c:972
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:242 [inline]
 tlb_flush_mmu+0x780/0x910 mm/mmu_gather.c:249
 tlb_finish_mmu+0xcb/0x200 mm/mmu_gather.c:340
 exit_mmap+0x404/0x7a0 mm/mmap.c:3203
 __mmput+0x111/0x370 kernel/fork.c:1101
 exit_mm+0x60a/0x770 kernel/exit.c:501
 do_exit+0x6ae/0x2510 kernel/exit.c:812
 do_group_exit+0x168/0x2d0 kernel/exit.c:922
 __do_sys_exit_group+0x13/0x20 kernel/exit.c:933
 __ia32_sys_exit_group+0x0/0x40 kernel/exit.c:931
 __x64_sys_exit_group+0x37/0x40 kernel/exit.c:931
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff888037b29200: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888037b29280: 00 00 00 04 fc fc fc fc 00 00 00 fc fc fc fc fc
>ffff888037b29300: fa fb fb fb fc fc fc fc 00 00 00 04 fc fc fc fc
                         ^
 ffff888037b29380: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888037b29400: fa fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
==================================================================