This issue is unrelated to the SYN cookie check in test-kernel-security.py. It just so happens that the test caught the bug. Here's two kernel stack dumps that I see in the logs after booting the 2.6.32-61-generic #123 kernel:
sysctl table check failed: /net/core/somaxconn .3.1.18 Missing strategy Pid: 1, comm: swapper Not tainted 2.6.32-61-generic #123-Ubuntu Call Trace: [<ffffffff8108f509>] set_fail+0x59/0x60 [<ffffffff8108f83b>] sysctl_check_table+0x16b/0x4b0 [<ffffffff8108f84c>] sysctl_check_table+0x17c/0x4b0 [<ffffffff8108f84c>] sysctl_check_table+0x17c/0x4b0 [<ffffffff8107235d>] __register_sysctl_paths+0x11d/0x360 [<ffffffff8108f84c>] ? sysctl_check_table+0x17c/0x4b0 [<ffffffff81535181>] register_net_sysctl_table+0x61/0x70 [<ffffffff81462765>] sysctl_core_net_init+0x45/0xb0 [<ffffffff81461b08>] register_pernet_operations+0x48/0x100 [<ffffffff8188e882>] ? sysctl_core_init+0x0/0x38 [<ffffffff81461c6c>] register_pernet_subsys+0x2c/0x50 [<ffffffff8188e8b8>] sysctl_core_init+0x36/0x38 [<ffffffff8100a04c>] do_one_initcall+0x3c/0x1a0 [<ffffffff818576d1>] do_basic_setup+0x54/0x66 [<ffffffff818577f1>] kernel_init+0x10e/0x162 [<ffffffff810141ea>] child_rip+0xa/0x20 [<ffffffff818576e3>] ? kernel_init+0x0/0x162 [<ffffffff810141e0>] ? child_rip+0x0/0x20 sysctl table check failed: /net/ipv4/ip_no_pmtu_disc .3.5.39 Missing strategy Pid: 1, comm: swapper Not tainted 2.6.32-61-generic #123-Ubuntu Call Trace: [<ffffffff8108f509>] set_fail+0x59/0x60 [<ffffffff8108f83b>] sysctl_check_table+0x16b/0x4b0 [<ffffffff8108f84c>] sysctl_check_table+0x17c/0x4b0 [<ffffffff8108f84c>] sysctl_check_table+0x17c/0x4b0 [<ffffffff8107235d>] __register_sysctl_paths+0x11d/0x360 [<ffffffff811a4808>] ? __proc_create+0xd8/0x130 [<ffffffff8189029a>] ? sysctl_ipv4_init+0x0/0x4e [<ffffffff810725cb>] register_sysctl_paths+0x2b/0x30 [<ffffffff818902b6>] sysctl_ipv4_init+0x1c/0x4e [<ffffffff8100a04c>] do_one_initcall+0x3c/0x1a0 [<ffffffff818576d1>] do_basic_setup+0x54/0x66 [<ffffffff818577f1>] kernel_init+0x10e/0x162 [<ffffffff810141ea>] child_rip+0xa/0x20 [<ffffffff818576e3>] ? kernel_init+0x0/0x162 [<ffffffff810141e0>] ? child_rip+0x0/0x20 The first stack dump involves the /net/core/somaxconn sysctl. Looking at the git log of changes that went into this kernel, I'd say that the following commit is the likely culprit: d77028f net: check net.core.somaxconn sysctl values -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1326473 Title: No /proc/sys/net/ipv4/tcp_syncookies present with 2.6.32-61-generic #123 in -proposed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1326473/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
