+// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/pipe.c
*
.get = generic_pipe_buf_get,
};
+static const struct pipe_buf_operations anon_pipe_buf_nomerge_ops = {
+ .can_merge = 0,
+ .confirm = generic_pipe_buf_confirm,
+ .release = anon_pipe_buf_release,
+ .steal = anon_pipe_buf_steal,
+ .get = generic_pipe_buf_get,
+};
+
static const struct pipe_buf_operations packet_pipe_buf_ops = {
.can_merge = 0,
.confirm = generic_pipe_buf_confirm,
.get = generic_pipe_buf_get,
};
+void pipe_buf_mark_unmergeable(struct pipe_buffer *buf)
+{
+ if (buf->ops == &anon_pipe_buf_ops)
+ buf->ops = &anon_pipe_buf_nomerge_ops;
+}
+
static ssize_t
pipe_read(struct kiocb *iocb, struct iov_iter *to)
{
static bool too_many_pipe_buffers_soft(unsigned long user_bufs)
{
- return pipe_user_pages_soft && user_bufs >= pipe_user_pages_soft;
+ return pipe_user_pages_soft && user_bufs > pipe_user_pages_soft;
}
static bool too_many_pipe_buffers_hard(unsigned long user_bufs)
{
- return pipe_user_pages_hard && user_bufs >= pipe_user_pages_hard;
+ return pipe_user_pages_hard && user_bufs > pipe_user_pages_hard;
+}
+
+static bool is_unprivileged_user(void)
+{
+ return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
}
struct pipe_inode_info *alloc_pipe_info(void)
user_bufs = account_pipe_buffers(user, 0, pipe_bufs);
- if (too_many_pipe_buffers_soft(user_bufs)) {
+ if (too_many_pipe_buffers_soft(user_bufs) && is_unprivileged_user()) {
user_bufs = account_pipe_buffers(user, pipe_bufs, 1);
pipe_bufs = 1;
}
- if (too_many_pipe_buffers_hard(user_bufs))
+ if (too_many_pipe_buffers_hard(user_bufs) && is_unprivileged_user())
goto out_revert_acct;
pipe->bufs = kcalloc(pipe_bufs, sizeof(struct pipe_buffer),
/*
* Currently we rely on the pipe array holding a power-of-2 number
- * of pages.
+ * of pages. Returns 0 on error.
*/
static inline unsigned int round_pipe_size(unsigned int size)
{
unsigned long nr_pages;
+ if (size < pipe_min_size)
+ size = pipe_min_size;
+
nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ if (nr_pages == 0)
+ return 0;
+
return roundup_pow_of_two(nr_pages) << PAGE_SHIFT;
}
long ret = 0;
size = round_pipe_size(arg);
+ if (size == 0)
+ return -EINVAL;
nr_pages = size >> PAGE_SHIFT;
if (!nr_pages)
if (nr_pages > pipe->buffers &&
(too_many_pipe_buffers_hard(user_bufs) ||
too_many_pipe_buffers_soft(user_bufs)) &&
- !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) {
+ is_unprivileged_user()) {
ret = -EPERM;
goto out_revert_acct;
}
int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf,
size_t *lenp, loff_t *ppos)
{
+ unsigned int rounded_pipe_max_size;
int ret;
- ret = proc_dointvec_minmax(table, write, buf, lenp, ppos);
+ ret = proc_douintvec_minmax(table, write, buf, lenp, ppos);
if (ret < 0 || !write)
return ret;
- pipe_max_size = round_pipe_size(pipe_max_size);
+ rounded_pipe_max_size = round_pipe_size(pipe_max_size);
+ if (rounded_pipe_max_size == 0)
+ return -EINVAL;
+
+ pipe_max_size = rounded_pipe_max_size;
return ret;
}