================================================================== BUG: KASAN: use-after-free in tipc_group_self+0x1a2/0x1b0 net/tipc/group.c:335 Read of size 4 at addr ffff8801d2958a6c by task syzkaller027452/2996 CPU: 1 PID: 2996 Comm: syzkaller027452 Not tainted 4.14.0-rc4+ #84 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 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_load4_noabort+0x14/0x20 mm/kasan/report.c:429 tipc_group_self+0x1a2/0x1b0 net/tipc/group.c:335 tipc_sk_leave+0xfc/0x200 net/tipc/socket.c:2781 tipc_release+0x154/0xfd0 net/tipc/socket.c:575 sock_release+0x8d/0x1e0 net/socket.c:597 sock_close+0x16/0x20 net/socket.c:1126 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:112 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0x9d2/0x1af0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 SYSC_exit_group kernel/exit.c:979 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:977 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x43e978 RSP: 002b:00007ffd9aac8a18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043e978 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000006ca018 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 0000000020004fe4 R11: 0000000000000246 R12: 00000000004016a0 R13: 0000000000401730 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 2996: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 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:3627 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:666 [inline] tipc_group_create+0x116/0x9c0 net/tipc/group.c:167 tipc_sk_join net/tipc/socket.c:2751 [inline] tipc_setsockopt+0x25e/0xc00 net/tipc/socket.c:2863 SYSC_setsockopt net/socket.c:1852 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1831 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 2996: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 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:3503 [inline] kfree+0xca/0x250 mm/slab.c:3820 tipc_group_delete+0x2c0/0x3c0 net/tipc/group.c:206 tipc_sk_join net/tipc/socket.c:2764 [inline] tipc_setsockopt+0xb33/0xc00 net/tipc/socket.c:2863 SYSC_setsockopt net/socket.c:1852 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1831 entry_SYSCALL_64_fastpath+0x1f/0xbe The buggy address belongs to the object at ffff8801d2958a00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 108 bytes inside of 192-byte region [ffff8801d2958a00, ffff8801d2958ac0) The buggy address belongs to the page: page:ffffea00074a5600 count:1 mapcount:0 mapping:ffff8801d2958000 index:0xffff8801d2958000 flags: 0x200000000000100(slab) raw: 0200000000000100 ffff8801d2958000 ffff8801d2958000 0000000100000009 raw: ffff8801dac01140 ffffea0007650420 ffff8801dac00040 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d2958900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801d2958980: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801d2958a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d2958a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801d2958b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================