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Diffstat (limited to 'fs/pipe.c')
-rw-r--r--fs/pipe.c32
1 files changed, 25 insertions, 7 deletions
diff --git a/fs/pipe.c b/fs/pipe.c
index 8e0d9f26dfad..34345535f63d 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -609,12 +609,17 @@ static unsigned long account_pipe_buffers(struct user_struct *user,
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)
@@ -633,12 +638,12 @@ 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),
@@ -1018,13 +1023,19 @@ const struct file_operations pipefifo_fops = {
/*
* 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;
}
@@ -1040,6 +1051,8 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
long ret = 0;
size = round_pipe_size(arg);
+ if (size == 0)
+ return -EINVAL;
nr_pages = size >> PAGE_SHIFT;
if (!nr_pages)
@@ -1061,7 +1074,7 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg)
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;
}
@@ -1123,13 +1136,18 @@ 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);
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;
}