================================================================== BUG: KASAN: use-after-free in mqueue_get_tree+0x2ac/0x2e0 ipc/mqueue.c:362 Read of size 8 at addr ffff8801d8e6ab88 by task syz-executor3/21951 CPU: 1 PID: 21951 Comm: syz-executor3 Not tainted 4.19.0-rc3-next-20180912+ #72 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+0x1d3/0x2c4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 mqueue_get_tree+0x2ac/0x2e0 ipc/mqueue.c:362 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1787 mq_create_mount+0xe3/0x190 ipc/mqueue.c:415 mq_init_ns+0x15a/0x210 ipc/mqueue.c:1621 create_ipc_ns ipc/namespace.c:58 [inline] copy_ipcs+0x3d2/0x580 ipc/namespace.c:84 create_new_namespaces+0x376/0x900 kernel/nsproxy.c:87 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206 ksys_unshare+0x79c/0x10b0 kernel/fork.c:2535 __do_sys_unshare kernel/fork.c:2603 [inline] __se_sys_unshare kernel/fork.c:2601 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2601 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459d87 Code: 00 00 00 b8 63 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 3d 8a fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 10 01 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 1d 8a fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffd6d1967b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459d87 RDX: 0000000000000000 RSI: 00007ffd6d1967c0 RDI: 0000000008000000 RBP: 0000000000930b28 R08: 0000000000000000 R09: 0000000000000018 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000010 R13: 0000000000412cc0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 20903: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc_node+0x144/0x730 mm/slab.c:3644 __alloc_skb+0x119/0x770 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:995 [inline] __ip_append_data.isra.48+0x21d6/0x29b0 net/ipv4/ip_output.c:988 ip_append_data.part.49+0xef/0x170 net/ipv4/ip_output.c:1196 ip_append_data+0x6d/0x90 net/ipv4/ip_output.c:1185 raw_sendmsg+0x1220/0x4380 net/ipv4/raw.c:671 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 __sys_sendto+0x3d7/0x670 net/socket.c:1787 __do_sys_sendto net/socket.c:1799 [inline] __se_sys_sendto net/socket.c:1795 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1795 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 20903: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 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+0x83/0x290 mm/slab.c:3756 kfree_skbmem+0x154/0x230 net/core/skbuff.c:582 __kfree_skb net/core/skbuff.c:642 [inline] kfree_skb+0x1c3/0x580 net/core/skbuff.c:659 kfree_skb_list net/core/skbuff.c:668 [inline] skb_release_data+0x4af/0x880 net/core/skbuff.c:567 skb_release_all+0x4a/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] consume_skb+0x1ae/0x570 net/core/skbuff.c:701 skb_free_datagram+0x1a/0xf0 net/core/datagram.c:329 raw_recvmsg+0x248/0x8b0 net/ipv4/raw.c:801 inet_recvmsg+0x181/0x6d0 net/ipv4/af_inet.c:830 sock_recvmsg_nosec net/socket.c:795 [inline] sock_recvmsg+0xd0/0x110 net/socket.c:802 sock_read_iter+0x39b/0x570 net/socket.c:879 call_read_iter include/linux/fs.h:1819 [inline] do_iter_readv_writev+0x77c/0xa80 fs/read_write.c:678 do_iter_read+0x26e/0x650 fs/read_write.c:922 vfs_readv+0x175/0x1c0 fs/read_write.c:986 do_readv+0x11a/0x310 fs/read_write.c:1019 __do_sys_readv fs/read_write.c:1106 [inline] __se_sys_readv fs/read_write.c:1103 [inline] __x64_sys_readv+0x75/0xb0 fs/read_write.c:1103 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801d8e6ab80 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 8 bytes inside of 232-byte region [ffff8801d8e6ab80, ffff8801d8e6ac68) The buggy address belongs to the page: page:ffffea0007639a80 count:1 mapcount:0 mapping:ffff8801d9a04040 index:0xffff8801d8e6a540 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea00075ddd48 ffffea0006e12788 ffff8801d9a04040 raw: ffff8801d8e6a540 ffff8801d8e6a040 000000010000000a 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d8e6aa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d8e6ab00: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc >ffff8801d8e6ab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d8e6ac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff8801d8e6ac80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================