diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/filter.c | 86 | ||||
| -rw-r--r-- | net/core/sock_diag.c | 23 |
2 files changed, 80 insertions, 29 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index bb3c76458ca9..9730e7fe4770 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -629,6 +629,37 @@ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) } EXPORT_SYMBOL(sk_chk_filter); +static int sk_store_orig_filter(struct sk_filter *fp, + const struct sock_fprog *fprog) +{ + unsigned int fsize = sk_filter_proglen(fprog); + struct sock_fprog_kern *fkprog; + + fp->orig_prog = kmalloc(sizeof(*fkprog), GFP_KERNEL); + if (!fp->orig_prog) + return -ENOMEM; + + fkprog = fp->orig_prog; + fkprog->len = fprog->len; + fkprog->filter = kmemdup(fp->insns, fsize, GFP_KERNEL); + if (!fkprog->filter) { + kfree(fp->orig_prog); + return -ENOMEM; + } + + return 0; +} + +static void sk_release_orig_filter(struct sk_filter *fp) +{ + struct sock_fprog_kern *fprog = fp->orig_prog; + + if (fprog) { + kfree(fprog->filter); + kfree(fprog); + } +} + /** * sk_filter_release_rcu - Release a socket filter by rcu_head * @rcu: rcu_head that contains the sk_filter to free @@ -637,6 +668,7 @@ void sk_filter_release_rcu(struct rcu_head *rcu) { struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu); + sk_release_orig_filter(fp); bpf_jit_free(fp); } EXPORT_SYMBOL(sk_filter_release_rcu); @@ -669,8 +701,8 @@ static int __sk_prepare_filter(struct sk_filter *fp) int sk_unattached_filter_create(struct sk_filter **pfp, struct sock_fprog *fprog) { + unsigned int fsize = sk_filter_proglen(fprog); struct sk_filter *fp; - unsigned int fsize = sizeof(struct sock_filter) * fprog->len; int err; /* Make sure new filter is there and in the right amounts. */ @@ -680,10 +712,16 @@ int sk_unattached_filter_create(struct sk_filter **pfp, fp = kmalloc(sk_filter_size(fprog->len), GFP_KERNEL); if (!fp) return -ENOMEM; + memcpy(fp->insns, fprog->filter, fsize); atomic_set(&fp->refcnt, 1); fp->len = fprog->len; + /* Since unattached filters are not copied back to user + * space through sk_get_filter(), we do not need to hold + * a copy here, and can spare us the work. + */ + fp->orig_prog = NULL; err = __sk_prepare_filter(fp); if (err) @@ -716,7 +754,7 @@ EXPORT_SYMBOL_GPL(sk_unattached_filter_destroy); int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) { struct sk_filter *fp, *old_fp; - unsigned int fsize = sizeof(struct sock_filter) * fprog->len; + unsigned int fsize = sk_filter_proglen(fprog); unsigned int sk_fsize = sk_filter_size(fprog->len); int err; @@ -730,6 +768,7 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) fp = sock_kmalloc(sk, sk_fsize, GFP_KERNEL); if (!fp) return -ENOMEM; + if (copy_from_user(fp->insns, fprog->filter, fsize)) { sock_kfree_s(sk, fp, sk_fsize); return -EFAULT; @@ -738,6 +777,12 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) atomic_set(&fp->refcnt, 1); fp->len = fprog->len; + err = sk_store_orig_filter(fp, fprog); + if (err) { + sk_filter_uncharge(sk, fp); + return -ENOMEM; + } + err = __sk_prepare_filter(fp); if (err) { sk_filter_uncharge(sk, fp); @@ -750,6 +795,7 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk) if (old_fp) sk_filter_uncharge(sk, old_fp); + return 0; } EXPORT_SYMBOL_GPL(sk_attach_filter); @@ -769,6 +815,7 @@ int sk_detach_filter(struct sock *sk) sk_filter_uncharge(sk, filter); ret = 0; } + return ret; } EXPORT_SYMBOL_GPL(sk_detach_filter); @@ -851,34 +898,41 @@ void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) to->k = filt->k; } -int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, unsigned int len) +int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, + unsigned int len) { + struct sock_fprog_kern *fprog; struct sk_filter *filter; - int i, ret; + int ret = 0; lock_sock(sk); filter = rcu_dereference_protected(sk->sk_filter, - sock_owned_by_user(sk)); - ret = 0; + sock_owned_by_user(sk)); if (!filter) goto out; - ret = filter->len; + + /* We're copying the filter that has been originally attached, + * so no conversion/decode needed anymore. + */ + fprog = filter->orig_prog; + + ret = fprog->len; if (!len) + /* User space only enquires number of filter blocks. */ goto out; + ret = -EINVAL; - if (len < filter->len) + if (len < fprog->len) goto out; ret = -EFAULT; - for (i = 0; i < filter->len; i++) { - struct sock_filter fb; - - sk_decode_filter(&filter->insns[i], &fb); - if (copy_to_user(&ubuf[i], &fb, sizeof(fb))) - goto out; - } + if (copy_to_user(ubuf, fprog->filter, sk_filter_proglen(fprog))) + goto out; - ret = filter->len; + /* Instead of bytes, the API requests to return the number + * of filter blocks. + */ + ret = fprog->len; out: release_sock(sk); return ret; diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c index a0e9cf6379de..d7af18859322 100644 --- a/net/core/sock_diag.c +++ b/net/core/sock_diag.c @@ -52,9 +52,10 @@ EXPORT_SYMBOL_GPL(sock_diag_put_meminfo); int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk, struct sk_buff *skb, int attrtype) { - struct nlattr *attr; + struct sock_fprog_kern *fprog; struct sk_filter *filter; - unsigned int len; + struct nlattr *attr; + unsigned int flen; int err = 0; if (!ns_capable(user_ns, CAP_NET_ADMIN)) { @@ -63,24 +64,20 @@ int sock_diag_put_filterinfo(struct user_namespace *user_ns, struct sock *sk, } rcu_read_lock(); - filter = rcu_dereference(sk->sk_filter); - len = filter ? filter->len * sizeof(struct sock_filter) : 0; + if (!filter) + goto out; - attr = nla_reserve(skb, attrtype, len); + fprog = filter->orig_prog; + flen = sk_filter_proglen(fprog); + + attr = nla_reserve(skb, attrtype, flen); if (attr == NULL) { err = -EMSGSIZE; goto out; } - if (filter) { - struct sock_filter *fb = (struct sock_filter *)nla_data(attr); - int i; - - for (i = 0; i < filter->len; i++, fb++) - sk_decode_filter(&filter->insns[i], fb); - } - + memcpy(nla_data(attr), fprog->filter, flen); out: rcu_read_unlock(); return err; |