KASAN: use-after-free Read in inet_create (2)
From: syzbot <hidden>
Date: 2018-07-16 08:22:05
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Hello, syzbot found the following crash on: HEAD commit: 483d835c8189 Add linux-next specific files for 20180713 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=11c231c2400000 kernel config: https://syzkaller.appspot.com/x/.config?x=60e5ac2478928314 dashboard link: https://syzkaller.appspot.com/bug?extid=222be66e5d94f87d8015 compiler: gcc (GCC) 8.0.1 20180413 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+222be66e5d94f87d8015@syzkaller.appspotmail.com team0 (unregistering): Port device team_slave_0 removed bond0 (unregistering): Releasing backup interface bond_slave_1 bond0 (unregistering): Releasing backup interface bond_slave_0 bond0 (unregistering): Released all slaves ================================================================== BUG: KASAN: use-after-free in inet_create+0xfdb/0x1070 net/ipv4/af_inet.c:339 Read of size 4 at addr ffff8801b09a87c4 by task kworker/u4:1/22 CPU: 1 PID: 22 Comm: kworker/u4:1 Not tainted 4.18.0-rc4-next-20180713+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: krdsd rds_connect_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 inet_create+0xfdb/0x1070 net/ipv4/af_inet.c:339 __sock_create+0x53c/0x940 net/socket.c:1268 sock_create_kern+0x3b/0x50 net/socket.c:1314 rds_tcp_conn_path_connect+0x2a3/0x960 net/rds/tcp_connect.c:108 rds_connect_worker+0x190/0x260 net/rds/threads.c:175 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Allocated by task 4480: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 kmem_cache_zalloc include/linux/slab.h:697 [inline] net_alloc net/core/net_namespace.c:383 [inline] copy_net_ns+0x15b/0x4d0 net/core/net_namespace.c:423 create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206 ksys_unshare+0x723/0xfb0 kernel/fork.c:2433 __do_sys_unshare kernel/fork.c:2501 [inline] __se_sys_unshare kernel/fork.c:2499 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2499 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 22: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 net_free net/core/net_namespace.c:399 [inline] net_drop_ns.part.13+0x129/0x150 net/core/net_namespace.c:406 net_drop_ns net/core/net_namespace.c:405 [inline] cleanup_net+0x6bb/0xb50 net/core/net_namespace.c:541 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff8801b09a80c0 which belongs to the cache net_namespace of size 8448 The buggy address is located 1796 bytes inside of 8448-byte region [ffff8801b09a80c0, ffff8801b09aa1c0) The buggy address belongs to the page: page:ffffea0006c26a00 count:1 mapcount:0 mapping:ffff8801d9bdae40 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffffea0007398808 ffffea0007393408 ffff8801d9bdae40 raw: 0000000000000000 ffff8801b09a80c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b09a8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b09a8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801b09a8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^ ffff8801b09a8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b09a8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot.