================================================================== BUG: KASAN: use-after-free in __list_add_valid+0x9a/0xa0 lib/list_debug.c:26 Read of size 8 at addr ffff8880a646f5a8 by task syz-executor.1/728 CPU: 0 PID: 728 Comm: syz-executor.1 Not tainted 5.2.0-rc3-next-20190607 #11 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 __list_add_valid+0x9a/0xa0 lib/list_debug.c:26 __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] register_shrinker_prepared+0x3d/0x190 mm/vmscan.c:414 register_shrinker+0x36/0x50 mm/vmscan.c:428 nfsd_reply_cache_init+0x1f9/0x4d0 fs/nfsd/nfscache.c:158 nfsd_init_net+0x21e/0x590 fs/nfsd/nfsctl.c:1245 ops_init+0xb3/0x410 net/core/net_namespace.c:130 setup_net+0x2d3/0x740 net/core/net_namespace.c:316 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:439 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x444/0x980 kernel/fork.c:2717 __do_sys_unshare kernel/fork.c:2785 [inline] __se_sys_unshare kernel/fork.c:2783 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2783 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff21c834c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000459279 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000060000000 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff21c8356d4 R13: 00000000004c8759 R14: 00000000004df1e0 R15: 00000000ffffffff Allocated by task 310: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 __do_kmalloc mm/slab.c:3654 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3663 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:742 [inline] ops_init+0xff/0x410 net/core/net_namespace.c:120 setup_net+0x2d3/0x740 net/core/net_namespace.c:316 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:439 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x444/0x980 kernel/fork.c:2717 __do_sys_unshare kernel/fork.c:2785 [inline] __se_sys_unshare kernel/fork.c:2783 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2783 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 310: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3426 [inline] kfree+0x106/0x2a0 mm/slab.c:3753 ops_init+0xd1/0x410 net/core/net_namespace.c:135 setup_net+0x2d3/0x740 net/core/net_namespace.c:316 copy_net_ns+0x1df/0x340 net/core/net_namespace.c:439 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x444/0x980 kernel/fork.c:2717 __do_sys_unshare kernel/fork.c:2785 [inline] __se_sys_unshare kernel/fork.c:2783 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2783 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a646f240 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 872 bytes inside of 1024-byte region [ffff8880a646f240, ffff8880a646f640) The buggy address belongs to the page: page:ffffea0002991b80 refcount:1 mapcount:0 mapping:ffff8880aa400ac0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00022b4108 ffffea00021aba08 ffff8880aa400ac0 raw: 0000000000000000 ffff8880a646e040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a646f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a646f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a646f580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a646f600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880a646f680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================