Revision 07998281c268592963e1cd623fe6ab0270b65ae4 authored by Florian Westphal on 05 February 2021, 11:56:43 UTC, committed by Pablo Neira Ayuso on 08 February 2021, 23:04:14 UTC
The origin skip check needs to re-test the zone. Else, we might skip a colliding tuple in the reply direction. This only occurs when using 'directional zones' where origin tuples reside in different zones but the reply tuples share the same zone. This causes the new conntrack entry to be dropped at confirmation time because NAT clash resolution was elided. Fixes: 4e35c1cb9460240 ("netfilter: nf_nat: skip nat clash resolution for same-origin entries") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1 parent ce7536b
kernel_read_file.c
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/fs.h>
#include <linux/fs_struct.h>
#include <linux/kernel_read_file.h>
#include <linux/security.h>
#include <linux/vmalloc.h>
/**
* kernel_read_file() - read file contents into a kernel buffer
*
* @file file to read from
* @offset where to start reading from (see below).
* @buf pointer to a "void *" buffer for reading into (if
* *@buf is NULL, a buffer will be allocated, and
* @buf_size will be ignored)
* @buf_size size of buf, if already allocated. If @buf not
* allocated, this is the largest size to allocate.
* @file_size if non-NULL, the full size of @file will be
* written here.
* @id the kernel_read_file_id identifying the type of
* file contents being read (for LSMs to examine)
*
* @offset must be 0 unless both @buf and @file_size are non-NULL
* (i.e. the caller must be expecting to read partial file contents
* via an already-allocated @buf, in at most @buf_size chunks, and
* will be able to determine when the entire file was read by
* checking @file_size). This isn't a recommended way to read a
* file, though, since it is possible that the contents might
* change between calls to kernel_read_file().
*
* Returns number of bytes read (no single read will be bigger
* than INT_MAX), or negative on error.
*
*/
int kernel_read_file(struct file *file, loff_t offset, void **buf,
size_t buf_size, size_t *file_size,
enum kernel_read_file_id id)
{
loff_t i_size, pos;
size_t copied;
void *allocated = NULL;
bool whole_file;
int ret;
if (offset != 0 && (!*buf || !file_size))
return -EINVAL;
if (!S_ISREG(file_inode(file)->i_mode))
return -EINVAL;
ret = deny_write_access(file);
if (ret)
return ret;
i_size = i_size_read(file_inode(file));
if (i_size <= 0) {
ret = -EINVAL;
goto out;
}
/* The file is too big for sane activities. */
if (i_size > INT_MAX) {
ret = -EFBIG;
goto out;
}
/* The entire file cannot be read in one buffer. */
if (!file_size && offset == 0 && i_size > buf_size) {
ret = -EFBIG;
goto out;
}
whole_file = (offset == 0 && i_size <= buf_size);
ret = security_kernel_read_file(file, id, whole_file);
if (ret)
goto out;
if (file_size)
*file_size = i_size;
if (!*buf)
*buf = allocated = vmalloc(i_size);
if (!*buf) {
ret = -ENOMEM;
goto out;
}
pos = offset;
copied = 0;
while (copied < buf_size) {
ssize_t bytes;
size_t wanted = min_t(size_t, buf_size - copied,
i_size - pos);
bytes = kernel_read(file, *buf + copied, wanted, &pos);
if (bytes < 0) {
ret = bytes;
goto out_free;
}
if (bytes == 0)
break;
copied += bytes;
}
if (whole_file) {
if (pos != i_size) {
ret = -EIO;
goto out_free;
}
ret = security_kernel_post_read_file(file, *buf, i_size, id);
}
out_free:
if (ret < 0) {
if (allocated) {
vfree(*buf);
*buf = NULL;
}
}
out:
allow_write_access(file);
return ret == 0 ? copied : ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file);
int kernel_read_file_from_path(const char *path, loff_t offset, void **buf,
size_t buf_size, size_t *file_size,
enum kernel_read_file_id id)
{
struct file *file;
int ret;
if (!path || !*path)
return -EINVAL;
file = filp_open(path, O_RDONLY, 0);
if (IS_ERR(file))
return PTR_ERR(file);
ret = kernel_read_file(file, offset, buf, buf_size, file_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
int kernel_read_file_from_path_initns(const char *path, loff_t offset,
void **buf, size_t buf_size,
size_t *file_size,
enum kernel_read_file_id id)
{
struct file *file;
struct path root;
int ret;
if (!path || !*path)
return -EINVAL;
task_lock(&init_task);
get_fs_root(init_task.fs, &root);
task_unlock(&init_task);
file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0);
path_put(&root);
if (IS_ERR(file))
return PTR_ERR(file);
ret = kernel_read_file(file, offset, buf, buf_size, file_size, id);
fput(file);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns);
int kernel_read_file_from_fd(int fd, loff_t offset, void **buf,
size_t buf_size, size_t *file_size,
enum kernel_read_file_id id)
{
struct fd f = fdget(fd);
int ret = -EBADF;
if (!f.file)
goto out;
ret = kernel_read_file(f.file, offset, buf, buf_size, file_size, id);
out:
fdput(f);
return ret;
}
EXPORT_SYMBOL_GPL(kernel_read_file_from_fd);
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