[PATCH 06/16] vc_screen: sanitize types in vcs_write

Jiri Slaby
2020-08-18T08:58:13Z

* ret can carry error codes, so make it signed, i.e. ssize_t
* pos is derived from the passed ppos, so make it long enough, i.e.
loff_t
* attr is a boolean, so...
* size is limited by vcs_size() which returns an int
* written, p, orig_count and this_round are always ">= 0" and "< size",
so uint is enough
* col and max_col are derived from vc->vc_cols (uint) and p, so make
them uint too
* place con_buf0 and con_buf declaration to a single line

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/tty/vt/vc_screen.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
index 8aa0d50bcac7..2571d9067b08 100644
--- a/drivers/tty/vt/vc_screen.c
+++ b/drivers/tty/vt/vc_screen.c
@@ -459,14 +459,13 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
struct inode *inode = file_inode(file);
struct vc_data *vc;
- long pos;
- long attr, size, written;
- char *con_buf0;
- int col, maxcol;
+ char *con_buf0, *con_buf;
u16 *org0 = NULL, *org = NULL;
- size_t ret;
- char *con_buf;
- bool viewed;
+ unsigned int written, col, maxcol;
+ int size;
+ ssize_t ret;
+ loff_t pos;
+ bool viewed, attr;

if (use_unicode(inode))
return -EOPNOTSUPP;
@@ -500,9 +499,7 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
count = size - pos;
written = 0;
while (count) {
- long this_round = count;
- size_t orig_count;
- long p;
+ unsigned int orig_count, p, this_round = count;

if (this_round > CON_BUF_SIZE)
this_round = CON_BUF_SIZE;
--
2.28.0