================================================================== BUG: KASAN: use-after-free in rb_first_postorder+0x7c/0xa0 lib/rbtree.c:671 A link change request failed with some changes committed already. Interface lo may have been left with an inconsistent configuration, please check. Read of size 8 at addr ffff8801c759fc00 by task syz-executor3/3548 CPU: 1 PID: 3548 Comm: syz-executor3 Not tainted 4.15.0-rc7+ #181 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 rb_first_postorder+0x7c/0xa0 lib/rbtree.c:671 tipc_group_join+0x120/0x2d0 net/tipc/group.c:210 tipc_sk_join net/tipc/socket.c:2781 [inline] tipc_setsockopt+0x67e/0xcc0 net/tipc/socket.c:2876 SYSC_setsockopt net/socket.c:1821 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1800 entry_SYSCALL_64_fastpath+0x23/0x9a RIP: 0033:0x452ac9 RSP: 002b:00007f128dc46c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9 RDX: 0000000000000087 RSI: 000000000000010f RDI: 0000000000000013 RBP: 00000000000003aa R08: 0000000000000010 R09: 0000000000000000 R10: 0000000020265000 R11: 0000000000000212 R12: 00000000006f3890 R13: 00000000ffffffff R14: 00007f128dc476d4 R15: 0000000000000000 Allocated by task 3548: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3610 kmalloc include/linux/slab.h:499 [inline] kzalloc include/linux/slab.h:688 [inline] tipc_group_create+0x144/0x900 net/tipc/group.c:180 tipc_sk_join net/tipc/socket.c:2762 [inline] tipc_setsockopt+0x274/0xcc0 net/tipc/socket.c:2876 SYSC_setsockopt net/socket.c:1821 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1800 entry_SYSCALL_64_fastpath+0x23/0x9a Freed by task 3548: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3488 [inline] kfree+0xd6/0x260 mm/slab.c:3803 tipc_group_delete+0x2c8/0x3d0 net/tipc/group.c:234 tipc_sk_join net/tipc/socket.c:2775 [inline] tipc_setsockopt+0xba3/0xcc0 net/tipc/socket.c:2876 SYSC_setsockopt net/socket.c:1821 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1800 entry_SYSCALL_64_fastpath+0x23/0x9a The buggy address belongs to the object at ffff8801c759fc00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 0 bytes inside of 128-byte region [ffff8801c759fc00, ffff8801c759fc80) The buggy address belongs to the page: page:ffffea00071d67c0 count:1 mapcount:0 mapping:ffff8801c759f000 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801c759f000 0000000000000000 0000000100000015 raw: ffffea00070f7960 ffffea0007639720 ffff8801dac00640 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c759fb00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801c759fb80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801c759fc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c759fc80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801c759fd00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================