================================================================== BUG: KASAN: use-after-free in reuseport_alloc+0x2dc/0x2f0 net/core/sock_reuseport.c:78 Write of size 8 at addr ffff888050852698 by task syz-executor.3/7362 CPU: 1 PID: 7362 Comm: syz-executor.3 Not tainted 5.10.0-rc6-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+0x107/0x163 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 reuseport_alloc+0x2dc/0x2f0 net/core/sock_reuseport.c:78 reuseport_add_sock+0x708/0x8d0 net/core/sock_reuseport.c:145 __sctp_hash_endpoint net/sctp/input.c:750 [inline] sctp_hash_endpoint+0x4fe/0x5f0 net/sctp/input.c:778 sctp_listen_start net/sctp/socket.c:8390 [inline] sctp_inet_listen+0x71c/0x930 net/sctp/socket.c:8445 __sys_listen+0x17d/0x250 net/socket.c:1668 __do_sys_listen net/socket.c:1677 [inline] __se_sys_listen net/socket.c:1675 [inline] __x64_sys_listen+0x50/0x70 net/socket.c:1675 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e159 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd41022dc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000032 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 000000000045e159 RDX: 0000000000000000 RSI: 0000000000000050 RDI: 0000000000000004 RBP: 000000000119bfb8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffcc267db2f R14: 00007fd41022e9c0 R15: 000000000119bf8c Allocated by task 7362: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:506 [inline] slab_alloc_node mm/slub.c:2891 [inline] slab_alloc mm/slub.c:2899 [inline] kmem_cache_alloc+0x122/0x460 mm/slub.c:2904 sk_prot_alloc+0x5f/0x300 net/core/sock.c:1679 sk_alloc+0x32/0xbd0 net/core/sock.c:1739 inet6_create net/ipv6/af_inet6.c:183 [inline] inet6_create+0x3a4/0x1010 net/ipv6/af_inet6.c:110 __sock_create+0x3de/0x780 net/socket.c:1405 sock_create net/socket.c:1456 [inline] __sys_socket+0xef/0x200 net/socket.c:1498 __do_sys_socket net/socket.c:1507 [inline] __se_sys_socket net/socket.c:1505 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1505 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 7360: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3142 [inline] kmem_cache_free+0x82/0x350 mm/slub.c:3158 sk_prot_free net/core/sock.c:1720 [inline] __sk_destruct+0x574/0x8f0 net/core/sock.c:1807 sk_destruct+0xbd/0xe0 net/core/sock.c:1822 __sk_free+0xef/0x3d0 net/core/sock.c:1833 sk_free+0x78/0xa0 net/core/sock.c:1844 sock_put include/net/sock.h:1799 [inline] sctp_close+0x773/0x8f0 net/sctp/socket.c:1538 inet_release+0x12e/0x280 net/ipv4/af_inet.c:431 inet6_release+0x4c/0x70 net/ipv6/af_inet6.c:475 __sock_release+0xcd/0x280 net/socket.c:596 sock_close+0x18/0x20 net/socket.c:1255 __fput+0x285/0x920 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:151 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:164 [inline] exit_to_user_mode_prepare+0x17e/0x1a0 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:266 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888050852200 which belongs to the cache SCTPv6 of size 2040 The buggy address is located 1176 bytes inside of 2040-byte region [ffff888050852200, ffff8880508529f8) The buggy address belongs to the page: page:00000000be086b4f refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888050853300 pfn:0x50850 head:00000000be086b4f order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 ffffea00016f9800 0000000200000002 ffff8880216b3c80 raw: ffff888050853300 00000000800f000b 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888050852580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050852600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888050852680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888050852700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888050852780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================