lkml.org 
[lkml]   [2020]   [May]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4/6] switch readdir(2) to unsafe_copy_dirent_name()
Date
From: Al Viro <viro@zeniv.linux.org.uk>

... and the same for its compat counterpart

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/readdir.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/fs/readdir.c b/fs/readdir.c
index ed6aaad451aa..a9085016a619 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -157,17 +157,18 @@ static int fillonedir(struct dir_context *ctx, const char *name, int namlen,
}
buf->result++;
dirent = buf->dirent;
- if (!access_ok(dirent,
+ if (!user_write_access_begin(dirent,
(unsigned long)(dirent->d_name + namlen + 1) -
(unsigned long)dirent))
goto efault;
- if ( __put_user(d_ino, &dirent->d_ino) ||
- __put_user(offset, &dirent->d_offset) ||
- __put_user(namlen, &dirent->d_namlen) ||
- __copy_to_user(dirent->d_name, name, namlen) ||
- __put_user(0, dirent->d_name + namlen))
- goto efault;
+ unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
+ unsafe_put_user(offset, &dirent->d_offset, efault_end);
+ unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
+ unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
+ user_write_access_end();
return 0;
+efault_end:
+ user_write_access_end();
efault:
buf->result = -EFAULT;
return -EFAULT;
@@ -424,17 +425,18 @@ static int compat_fillonedir(struct dir_context *ctx, const char *name,
}
buf->result++;
dirent = buf->dirent;
- if (!access_ok(dirent,
+ if (!user_write_access_begin(dirent,
(unsigned long)(dirent->d_name + namlen + 1) -
(unsigned long)dirent))
goto efault;
- if ( __put_user(d_ino, &dirent->d_ino) ||
- __put_user(offset, &dirent->d_offset) ||
- __put_user(namlen, &dirent->d_namlen) ||
- __copy_to_user(dirent->d_name, name, namlen) ||
- __put_user(0, dirent->d_name + namlen))
- goto efault;
+ unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
+ unsafe_put_user(offset, &dirent->d_offset, efault_end);
+ unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
+ unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
+ user_write_access_end();
return 0;
+efault_end:
+ user_write_access_end();
efault:
buf->result = -EFAULT;
return -EFAULT;
--
2.11.0
\
 
 \ /
  Last update: 2020-05-29 01:50    [W:0.391 / U:1.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site