syzbot


KASAN: slab-out-of-bounds Read in tcp_sk_exit

Status: auto-closed as invalid on 2019/10/25 08:38
Reported-by: syzbot+dfc9db054bca3a83f4a0@syzkaller.appspotmail.com
First crash: 1246d, last: 1126d

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in inet_ctl_sock_destroy include/net/inet_common.h:56 [inline]
BUG: KASAN: slab-out-of-bounds in tcp_sk_exit+0x20d/0x240 net/ipv4/tcp_ipv4.c:2603
Read of size 8 at addr ffff888065da5858 by task kworker/u4:5/10056

CPU: 0 PID: 10056 Comm: kworker/u4:5 Not tainted 5.2.0-rc1+ #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188
 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 kasan_report+0x12/0x20 mm/kasan/common.c:614
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
 inet_ctl_sock_destroy include/net/inet_common.h:56 [inline]
 tcp_sk_exit+0x20d/0x240 net/ipv4/tcp_ipv4.c:2603
 ops_exit_list.isra.0+0xaa/0x150 net/core/net_namespace.c:154
 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:553
 process_one_work+0x989/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x354/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 29021:
 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_slab_alloc+0xf/0x20 mm/kasan/common.c:497
 slab_post_alloc_hook mm/slab.h:437 [inline]
 slab_alloc mm/slab.c:3326 [inline]
 kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3488
 sk_prot_alloc+0x67/0x2e0 net/core/sock.c:1602
 sk_alloc+0x39/0xf70 net/core/sock.c:1662
 inet_create net/ipv4/af_inet.c:325 [inline]
 inet_create+0x36a/0xe00 net/ipv4/af_inet.c:251
 __sock_create+0x3d8/0x730 net/socket.c:1430
 sock_create_kern+0x3b/0x50 net/socket.c:1499
 inet_ctl_sock_create+0x9d/0x1f0 net/ipv4/af_inet.c:1624
 tcp_sk_init+0x11b/0x12d0 net/ipv4/tcp_ipv4.c:2618
 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+0x440/0x980 kernel/fork.c:2692
 __do_sys_unshare kernel/fork.c:2760 [inline]
 __se_sys_unshare kernel/fork.c:2758 [inline]
 __ia32_sys_unshare+0x30/0x40 kernel/fork.c:2758
 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x27b/0xd7d arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 10056:
 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:3432 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3698
 sk_prot_free net/core/sock.c:1643 [inline]
 __sk_destruct+0x4bc/0x6e0 net/core/sock.c:1731
 sk_destruct+0x7b/0x90 net/core/sock.c:1739
 __sk_free+0xce/0x300 net/core/sock.c:1750
 sk_free+0x42/0x50 net/core/sock.c:1761
 sock_put include/net/sock.h:1728 [inline]
 sk_common_release+0x21c/0x330 net/core/sock.c:3181
 raw_close+0x22/0x30 net/ipv4/raw.c:708
 inet_release+0xff/0x1e0 net/ipv4/af_inet.c:432
 __sock_release+0x1f4/0x2a0 net/socket.c:607
 sock_release+0x18/0x20 net/socket.c:627
 inet_ctl_sock_destroy include/net/inet_common.h:56 [inline]
 tcp_sk_exit+0x185/0x240 net/ipv4/tcp_ipv4.c:2603
 ops_exit_list.isra.0+0xaa/0x150 net/core/net_namespace.c:154
 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:553
 process_one_work+0x989/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x354/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff888065da5280
 which belongs to the cache RAW(49:syz2) of size 1352
The buggy address is located 144 bytes to the right of
 1352-byte region [ffff888065da5280, ffff888065da57c8)
The buggy address belongs to the page:
page:ffffea0001976900 refcount:1 mapcount:0 mapping:ffff88808f5bdc00 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea000278af88 ffffea0002355808 ffff88808f5bdc00
raw: 0000000000000000 ffff888065da4080 0000000100000005 ffff888099d2d400
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff888099d2d400

Memory state around the buggy address:
 ffff888065da5700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888065da5780: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
>ffff888065da5800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                    ^
 ffff888065da5880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888065da5900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (5):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-386 2019/05/24 21:58 upstream c50bbf615f2f 85c57315 .config log report
ci-upstream-net-this-kasan-gce 2019/05/15 06:21 net 0fe9f173d6cd bd4e3ac7 .config log report
ci-upstream-net-this-kasan-gce 2019/01/31 07:16 net e15aa3b2b138 aa432daf .config log report
ci-upstream-net-kasan-gce 2019/05/31 17:56 net-next c9bb6165a16e 142ce681 .config log report
ci-upstream-net-kasan-gce 2019/03/07 08:13 net-next d9862cfbe209 18215b8d .config log report