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switch readdir(2) to unsafe_copy_dirent_name() 

... and the same for its compat counterpart

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-02-18 14:39:56 -05:00
parent b44f687386
commit 391b7461d4
1 changed files with 16 additions and 14 deletions
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30
fs/readdir.c
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@ -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;