The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 040ee69226f8a96b7943645d68f41d5d44b5ff7d Mon Sep 17 00:00:00 2001
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Date: Sat, 2 Dec 2017 20:20:38 -0500
Subject: [PATCH] fix "netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of
'xt_bpf_info_v1'"
Descriptor table is a shared object; it's not a place where you can
stick temporary references to files, especially when we don't need
an opened file at all.
Cc: stable@xxxxxxxxxxxxxxx # v4.14
Fixes: 98589a0998b8 ("netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'")
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index e55e4255a210..b63a592ad29d 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -419,6 +419,8 @@ static inline int bpf_map_attr_numa_node(const union bpf_attr *attr)
attr->numa_node : NUMA_NO_NODE;
}
+struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type);
+
#else /* !CONFIG_BPF_SYSCALL */
static inline struct bpf_prog *bpf_prog_get(u32 ufd)
{
@@ -506,6 +508,12 @@ static inline int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu,
{
return 0;
}
+
+static inline struct bpf_prog *bpf_prog_get_type_path(const char *name,
+ enum bpf_prog_type type)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
#endif /* CONFIG_BPF_SYSCALL */
static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
@@ -514,6 +522,8 @@ static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
return bpf_prog_get_type_dev(ufd, type, false);
}
+bool bpf_prog_get_ok(struct bpf_prog *, enum bpf_prog_type *, bool);
+
int bpf_prog_offload_compile(struct bpf_prog *prog);
void bpf_prog_offload_destroy(struct bpf_prog *prog);
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index 01aaef1a77c5..5bb5e49ef4c3 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -368,7 +368,45 @@ out:
putname(pname);
return ret;
}
-EXPORT_SYMBOL_GPL(bpf_obj_get_user);
+
+static struct bpf_prog *__get_prog_inode(struct inode *inode, enum bpf_prog_type type)
+{
+ struct bpf_prog *prog;
+ int ret = inode_permission(inode, MAY_READ | MAY_WRITE);
+ if (ret)
+ return ERR_PTR(ret);
+
+ if (inode->i_op == &bpf_map_iops)
+ return ERR_PTR(-EINVAL);
+ if (inode->i_op != &bpf_prog_iops)
+ return ERR_PTR(-EACCES);
+
+ prog = inode->i_private;
+
+ ret = security_bpf_prog(prog);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ if (!bpf_prog_get_ok(prog, &type, false))
+ return ERR_PTR(-EINVAL);
+
+ return bpf_prog_inc(prog);
+}
+
+struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type)
+{
+ struct bpf_prog *prog;
+ struct path path;
+ int ret = kern_path(name, LOOKUP_FOLLOW, &path);
+ if (ret)
+ return ERR_PTR(ret);
+ prog = __get_prog_inode(d_backing_inode(path.dentry), type);
+ if (!IS_ERR(prog))
+ touch_atime(&path);
+ path_put(&path);
+ return prog;
+}
+EXPORT_SYMBOL(bpf_prog_get_type_path);
static void bpf_evict_inode(struct inode *inode)
{
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 2c4cfeaa8d5e..5cb783fc8224 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1057,7 +1057,7 @@ struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
}
EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
-static bool bpf_prog_get_ok(struct bpf_prog *prog,
+bool bpf_prog_get_ok(struct bpf_prog *prog,
enum bpf_prog_type *attach_type, bool attach_drv)
{
/* not an attachment, just a refcount inc, always allow */
diff --git a/net/netfilter/xt_bpf.c b/net/netfilter/xt_bpf.c
index 041da0d9c06f..fa2ca0a13619 100644
--- a/net/netfilter/xt_bpf.c
+++ b/net/netfilter/xt_bpf.c
@@ -52,18 +52,8 @@ static int __bpf_mt_check_fd(int fd, struct bpf_prog **ret)
static int __bpf_mt_check_path(const char *path, struct bpf_prog **ret)
{
- mm_segment_t oldfs = get_fs();
- int retval, fd;
-
- set_fs(KERNEL_DS);
- fd = bpf_obj_get_user(path, 0);
- set_fs(oldfs);
- if (fd < 0)
- return fd;
-
- retval = __bpf_mt_check_fd(fd, ret);
- sys_close(fd);
- return retval;
+ *ret = bpf_prog_get_type_path(path, BPF_PROG_TYPE_SOCKET_FILTER);
+ return PTR_ERR_OR_ZERO(*ret);
}
static int bpf_mt_check(const struct xt_mtchk_param *par)