Re: [PATCH 1/5] secmark: do not return early if there was no error

[James Morris]

On Tue, 12 Oct 2010, Eric Paris wrote:

> Commit 4a5a5c73 attempted to pass decent error messages back to userspace for
> netfilter errors.  In xt_SECMARK.c however the patch screwed up and returned
> on 0 (aka no error) early and didn't finish setting up secmark.  This results
> in a kernel BUG if you use SECMARK.
> 

Does this need to go into current Linus?

> ------------[ cut here ]------------
> kernel BUG at net/netfilter/xt_SECMARK.c:38!
> invalid opcode: 0000 [#1] SMP
> last sysfs file: /sys/devices/system/cpu/cpu2/cache/index2/shared_cpu_map
> CPU 0
> Modules linked in: xt_SECMARK iptable_mangle nfs lockd fscache nfs_acl
> auth_rpcgss sunrpc ip6t_REJECT nf_conntrack_ipv6 ip6table_filter ip6_tables
> uinput virtio_net virtio_balloon i2c_piix4 i2c_core joydev microcode ipv6
> virtio_blk virtio_pci virtio_ring virtio [last unloaded: speedstep_lib]
> 
> Pid: 0, comm: swapper Not tainted 2.6.36-0.8.rc2.git0.fc15.x86_64 #1 /KVM
> RIP: 0010:[<ffffffffa022117d>]  [<ffffffffa022117d>] secmark_tg+0x17/0x2e [xt_SECMARK]
> RSP: 0018:ffff880003e03a40  EFLAGS: 00010202
> RAX: ffff88001f3074b0 RBX: ffff88001f3073f0 RCX: ffff88001f307490
> RDX: ffff88001f307401 RSI: ffff880003e03b30 RDI: ffff88001f18e500
> RBP: ffff880003e03a40 R08: 0000000000000002 R09: ffff880003e03a10
> R10: ffff880003fd2ad8 R11: ffffffff00000001 R12: ffff88001a85d498
> R13: ffffe8ffff808240 R14: ffff88001ac133ae R15: ffff88001f18e500
> FS:  0000000000000000(0000) GS:ffff880003e00000(0000)
> knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: 000000000073b130 CR3: 000000000fdc0000 CR4: 00000000000006f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Process swapper (pid: 0, threadinfo ffffffff81a00000, task
> ffffffff81a4b020)
> Stack:
> ffff880003e03b90 ffffffff814599ff 0000000000003a18 0000000000000000
> ffff880003e03b70 ffffffffffffffb8 0000000000000000 ffffffff82a39d60
> ffff880003e03a90 ffffffff8140db60 ffff880003e03ae0 ffffffff8140f2c0
> Call Trace:
>  <IRQ>
> [<ffffffff814599ff>] ipt_do_table+0x58a/0x6e2
> [<ffffffff8140db60>] ? rcu_read_unlock+0x21/0x23
> [<ffffffff8140f2c0>] ? nf_conntrack_find_get+0xb4/0xc7
> [<ffffffffa021b182>] iptable_mangle_hook+0x10a/0x120 [iptable_mangle]
> [<ffffffff8140c226>] nf_iterate+0x46/0x89
> [<ffffffff8141d2e8>] ? ip_rcv_finish+0x0/0x3c6
> [<ffffffff8140c2e1>] nf_hook_slow+0x78/0xe3
> [<ffffffff8141d2e8>] ? ip_rcv_finish+0x0/0x3c6
> [<ffffffff81472f06>] ? run_filter+0x0/0xc0
> [<ffffffff813e6802>] ? dev_seq_stop+0x8/0x10
> [<ffffffff8141d2e8>] ? ip_rcv_finish+0x0/0x3c6
> [<ffffffff8141d9a9>] NF_HOOK.clone.6+0x46/0x58
> [<ffffffff8141dd93>] ip_rcv+0x21f/0x24c
> [<ffffffff813e7d43>] __netif_receive_skb+0x3e0/0x40a
> [<ffffffff813e8834>] netif_receive_skb+0x6c/0x73
> [<ffffffffa00c954e>] virtnet_poll+0x55b/0x6cb [virtio_net]
> [<ffffffff8107fb92>] ? lock_release+0x19a/0x1a6
> [<ffffffff813e9bc4>] net_rx_action+0xb1/0x1e3
> [<ffffffff8107d64b>] ? print_lock_contention_bug+0x1b/0xd5
> [<ffffffff8100ac1c>] ? call_softirq+0x1c/0x30
> [<ffffffff8105752a>] __do_softirq+0xfa/0x1cf
> [<ffffffff8107fb92>] ? lock_release+0x19a/0x1a6
> [<ffffffff8100ac1c>] call_softirq+0x1c/0x30
> [<ffffffff8100c3d9>] do_softirq+0x4b/0xa2
> [<ffffffff810576d0>] irq_exit+0x4a/0x8c
> [<ffffffff814a198d>] do_IRQ+0x9d/0xb4
> [<ffffffff8149b813>] ret_from_intr+0x0/0x16
>  <EOI>
> [<ffffffff81010faf>] ? default_idle+0x3c/0x61
> [<ffffffff8102c7b1>] ? native_safe_halt+0xb/0xd
> [<ffffffff810800c0>] ? trace_hardirqs_on+0xd/0xf
> [<ffffffff81010fb4>] default_idle+0x41/0x61
> [<ffffffff8100830b>] cpu_idle+0xb3/0x10f
> [<ffffffff814824c3>] rest_init+0xb7/0xbe
> [<ffffffff8148240c>] ? rest_init+0x0/0xbe
> [<ffffffff81d76c50>] start_kernel+0x412/0x41d
> [<ffffffff81d762c6>] x86_64_start_reservations+0xb1/0xb5
> [<ffffffff81d763c2>] x86_64_start_kernel+0xf8/0x107
> Code: 41 8a 04 24 88 05 1c 05 00 00 5a 89 d8 5b 41 5c 41 5d c9 c3 55 48 89 e5
> 0f 1f 44 00 00 48 8b 46 08 8a 10 3a 15 fd 04 00 00 74 02 <0f> 0b fe ca 75 0e
> 8b 40 04 89 87 b4 00 00 00 83 c8 ff c9 c3 0f
> RIP  [<ffffffffa022117d>] secmark_tg+0x17/0x2e [xt_SECMARK]
> RSP <ffff880003e03a40>
> ---[ end trace 9aa5d06a71143e74 ]---
> 
> Signed-off-by: Eric Paris <eparis@xxxxxxxxxx>
> ---
> 
>  net/netfilter/xt_SECMARK.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
> index 23b2d6c..364ad16 100644
> --- a/net/netfilter/xt_SECMARK.c
> +++ b/net/netfilter/xt_SECMARK.c
> @@ -101,7 +101,7 @@ static int secmark_tg_check(const struct xt_tgchk_param *par)
>  	switch (info->mode) {
>  	case SECMARK_MODE_SEL:
>  		err = checkentry_selinux(info);
> -		if (err <= 0)
> +		if (err)
>  			return err;
>  		break;
>  
> 

-- 
James Morris
<jmorris@xxxxxxxxx>
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