diff options
| -rw-r--r-- | include/linux/bpfilter.h | 2 | ||||
| -rw-r--r-- | net/bpfilter/bpfilter_kern.c | 28 | ||||
| -rw-r--r-- | net/ipv4/bpfilter/sockopt.c | 22 |
3 files changed, 29 insertions, 23 deletions
diff --git a/include/linux/bpfilter.h b/include/linux/bpfilter.h index 8ebcbdd70bdc..d815622cd31e 100644 --- a/include/linux/bpfilter.h +++ b/include/linux/bpfilter.h @@ -12,6 +12,8 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen); struct bpfilter_umh_ops { struct umh_info info; + /* since ip_getsockopt() can run in parallel, serialize access to umh */ + struct mutex lock; int (*sockopt)(struct sock *sk, int optname, char __user *optval, unsigned int optlen, bool is_set); diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index c0fcde910a7a..7ee4fea93637 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -13,9 +13,6 @@ extern char bpfilter_umh_start; extern char bpfilter_umh_end; -/* since ip_getsockopt() can run in parallel, serialize access to umh */ -static DEFINE_MUTEX(bpfilter_lock); - static void shutdown_umh(void) { struct task_struct *tsk; @@ -36,13 +33,6 @@ static void __stop_umh(void) shutdown_umh(); } -static void stop_umh(void) -{ - mutex_lock(&bpfilter_lock); - __stop_umh(); - mutex_unlock(&bpfilter_lock); -} - static int __bpfilter_process_sockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen, bool is_set) @@ -58,7 +48,6 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, req.cmd = optname; req.addr = (long __force __user)optval; req.len = optlen; - mutex_lock(&bpfilter_lock); if (!bpfilter_ops.info.pid) goto out; n = __kernel_write(bpfilter_ops.info.pipe_to_umh, &req, sizeof(req), @@ -80,7 +69,6 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, } ret = reply.status; out: - mutex_unlock(&bpfilter_lock); return ret; } @@ -99,7 +87,7 @@ static int start_umh(void) /* health check that usermode process started correctly */ if (__bpfilter_process_sockopt(NULL, 0, NULL, 0, 0) != 0) { - stop_umh(); + shutdown_umh(); return -EFAULT; } @@ -110,24 +98,30 @@ static int __init load_umh(void) { int err; - if (!bpfilter_ops.stop) - return -EFAULT; + mutex_lock(&bpfilter_ops.lock); + if (!bpfilter_ops.stop) { + err = -EFAULT; + goto out; + } err = start_umh(); if (!err && IS_ENABLED(CONFIG_INET)) { bpfilter_ops.sockopt = &__bpfilter_process_sockopt; bpfilter_ops.start = &start_umh; } - +out: + mutex_unlock(&bpfilter_ops.lock); return err; } static void __exit fini_umh(void) { + mutex_lock(&bpfilter_ops.lock); if (IS_ENABLED(CONFIG_INET)) { + shutdown_umh(); bpfilter_ops.start = NULL; bpfilter_ops.sockopt = NULL; } - stop_umh(); + mutex_unlock(&bpfilter_ops.lock); } module_init(load_umh); module_exit(fini_umh); diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c index de84ede4e765..1e976bb93d99 100644 --- a/net/ipv4/bpfilter/sockopt.c +++ b/net/ipv4/bpfilter/sockopt.c @@ -14,10 +14,12 @@ EXPORT_SYMBOL_GPL(bpfilter_ops); static void bpfilter_umh_cleanup(struct umh_info *info) { + mutex_lock(&bpfilter_ops.lock); bpfilter_ops.stop = true; fput(info->pipe_to_umh); fput(info->pipe_from_umh); info->pid = 0; + mutex_unlock(&bpfilter_ops.lock); } static int bpfilter_mbox_request(struct sock *sk, int optname, @@ -25,21 +27,28 @@ static int bpfilter_mbox_request(struct sock *sk, int optname, unsigned int optlen, bool is_set) { int err; - + mutex_lock(&bpfilter_ops.lock); if (!bpfilter_ops.sockopt) { + mutex_unlock(&bpfilter_ops.lock); err = request_module("bpfilter"); + mutex_lock(&bpfilter_ops.lock); if (err) - return err; - if (!bpfilter_ops.sockopt) - return -ECHILD; + goto out; + if (!bpfilter_ops.sockopt) { + err = -ECHILD; + goto out; + } } if (bpfilter_ops.stop) { err = bpfilter_ops.start(); if (err) - return err; + goto out; } - return bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set); + err = bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set); +out: + mutex_unlock(&bpfilter_ops.lock); + return err; } int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval, @@ -61,6 +70,7 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, static int __init bpfilter_sockopt_init(void) { + mutex_init(&bpfilter_ops.lock); bpfilter_ops.stop = true; bpfilter_ops.info.cmdline = "bpfilter_umh"; bpfilter_ops.info.cleanup = &bpfilter_umh_cleanup; |