From 249556192859490b6280552d4b877064f9f5ee48 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 22 Jun 2009 14:15:30 +0200 Subject: netfilter: nf_log: fix direct userspace memory access in proc handler Signed-off-by: Patrick McHardy --- net/netfilter/nf_log.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'net') diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c index 2fefe147750a..4e620305f28c 100644 --- a/net/netfilter/nf_log.c +++ b/net/netfilter/nf_log.c @@ -47,7 +47,6 @@ int nf_log_register(u_int8_t pf, struct nf_logger *logger) mutex_lock(&nf_log_mutex); if (pf == NFPROTO_UNSPEC) { - int i; for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) list_add_tail(&(logger->list[i]), &(nf_loggers_l[i])); } else { @@ -216,7 +215,7 @@ static const struct file_operations nflog_file_ops = { #endif /* PROC_FS */ #ifdef CONFIG_SYSCTL -struct ctl_path nf_log_sysctl_path[] = { +static struct ctl_path nf_log_sysctl_path[] = { { .procname = "net", .ctl_name = CTL_NET, }, { .procname = "netfilter", .ctl_name = NET_NETFILTER, }, { .procname = "nf_log", .ctl_name = CTL_UNNUMBERED, }, @@ -228,19 +227,26 @@ static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1]; static struct ctl_table_header *nf_log_dir_header; static int nf_log_proc_dostring(ctl_table *table, int write, struct file *filp, - void *buffer, size_t *lenp, loff_t *ppos) + void __user *buffer, size_t *lenp, loff_t *ppos) { const struct nf_logger *logger; + char buf[NFLOGGER_NAME_LEN]; + size_t size = *lenp; int r = 0; int tindex = (unsigned long)table->extra1; if (write) { - if (!strcmp(buffer, "NONE")) { + if (size > sizeof(buf)) + size = sizeof(buf); + if (copy_from_user(buf, buffer, size)) + return -EFAULT; + + if (!strcmp(buf, "NONE")) { nf_log_unbind_pf(tindex); return 0; } mutex_lock(&nf_log_mutex); - logger = __find_logger(tindex, buffer); + logger = __find_logger(tindex, buf); if (logger == NULL) { mutex_unlock(&nf_log_mutex); return -ENOENT; -- cgit v1.2.3-59-g8ed1b