IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
==================================================================
BUG: KASAN: use-after-free in __list_add_valid+0x93/0xa0 lib/list_debug.c:26
Read of size 8 at addr ffff888086cdd6a0 by task syz-executor.0/6751

CPU: 0 PID: 6751 Comm: syz-executor.0 Not tainted 4.19.114-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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396
 __list_add_valid+0x93/0xa0 lib/list_debug.c:26
 __list_add include/linux/list.h:60 [inline]
 list_add_tail include/linux/list.h:93 [inline]
 cma_listen_on_all drivers/infiniband/core/cma.c:2380 [inline]
 rdma_listen+0x609/0x880 drivers/infiniband/core/cma.c:3408
 ucma_listen+0x14d/0x1c0 drivers/infiniband/core/ucma.c:1100
 ucma_write+0x285/0x350 drivers/infiniband/core/ucma.c:1689
 __vfs_write+0xf7/0x760 fs/read_write.c:485
 vfs_write+0x206/0x550 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c849
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7a0894ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7a0894f6d4 RCX: 000000000045c849
RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000cc0 R14: 00000000004cee4e R15: 000000000076bf0c

Allocated by task 6743:
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
 kmem_cache_alloc_trace+0x14d/0x7a0 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 __rdma_create_id+0x5b/0x630 drivers/infiniband/core/cma.c:784
 ucma_create_id+0x1cb/0x5a0 drivers/infiniband/core/ucma.c:506
 ucma_write+0x285/0x350 drivers/infiniband/core/ucma.c:1689
 __vfs_write+0xf7/0x760 fs/read_write.c:485
 vfs_write+0x206/0x550 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 6742:
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xce/0x220 mm/slab.c:3822
 ucma_close+0x10b/0x320 drivers/infiniband/core/ucma.c:1770
 __fput+0x2cd/0x890 fs/file_table.c:278
 task_work_run+0x13f/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x25a/0x2b0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888086cdd4c0
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 480 bytes inside of
 2048-byte region [ffff888086cdd4c0, ffff888086cddcc0)
The buggy address belongs to the page:
page:ffffea00021b3700 count:1 mapcount:0 mapping:ffff88812c3dcc40 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea00027e0288 ffffea0002800388 ffff88812c3dcc40
raw: 0000000000000000 ffff888086cdc3c0 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888086cdd580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888086cdd600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888086cdd680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888086cdd700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888086cdd780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================