| From 9ef0298a8e5730d9a46d640014c727f3b4152870 Mon Sep 17 00:00:00 2001 |
| From: Jan Engelhardt <jengelh@medozas.de> |
| Date: Wed, 2 Mar 2011 12:10:13 +0100 |
| Subject: netfilter: nf_log: avoid oops in (un)bind with invalid nfproto values |
| |
| From: Jan Engelhardt <jengelh@medozas.de> |
| |
| commit 9ef0298a8e5730d9a46d640014c727f3b4152870 upstream. |
| |
| Like many other places, we have to check that the array index is |
| within allowed limits, or otherwise, a kernel oops and other nastiness |
| can ensue when we access memory beyond the end of the array. |
| |
| [ 5954.115381] BUG: unable to handle kernel paging request at 0000004000000000 |
| [ 5954.120014] IP: __find_logger+0x6f/0xa0 |
| [ 5954.123979] nf_log_bind_pf+0x2b/0x70 |
| [ 5954.123979] nfulnl_recv_config+0xc0/0x4a0 [nfnetlink_log] |
| [ 5954.123979] nfnetlink_rcv_msg+0x12c/0x1b0 [nfnetlink] |
| ... |
| |
| The problem goes back to v2.6.30-rc1~1372~1342~31 where nf_log_bind |
| was decoupled from nf_log_register. |
| |
| Reported-by: Miguel Di Ciurcio Filho <miguel.filho@gmail.com>, |
| via irc.freenode.net/#netfilter |
| Signed-off-by: Jan Engelhardt <jengelh@medozas.de> |
| Signed-off-by: Patrick McHardy <kaber@trash.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| net/netfilter/nf_log.c | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| --- a/net/netfilter/nf_log.c |
| +++ b/net/netfilter/nf_log.c |
| @@ -83,6 +83,8 @@ EXPORT_SYMBOL(nf_log_unregister); |
| |
| int nf_log_bind_pf(u_int8_t pf, const struct nf_logger *logger) |
| { |
| + if (pf >= ARRAY_SIZE(nf_loggers)) |
| + return -EINVAL; |
| mutex_lock(&nf_log_mutex); |
| if (__find_logger(pf, logger->name) == NULL) { |
| mutex_unlock(&nf_log_mutex); |
| @@ -96,6 +98,8 @@ EXPORT_SYMBOL(nf_log_bind_pf); |
| |
| void nf_log_unbind_pf(u_int8_t pf) |
| { |
| + if (pf >= ARRAY_SIZE(nf_loggers)) |
| + return; |
| mutex_lock(&nf_log_mutex); |
| rcu_assign_pointer(nf_loggers[pf], NULL); |
| mutex_unlock(&nf_log_mutex); |