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authorJoel Becker <joel.becker@oracle.com>2007-01-23 17:00:45 -0800
committerMark Fasheh <mark.fasheh@oracle.com>2007-02-07 12:17:08 -0800
commitff05d1c4643dd4260eb699396043d7e8009c0de4 (patch)
treefe3c601c3c8a2498c434a2d2c08e0192b4233299
parent[PATCH] ocfs2 heartbeat: clean up bio submission code (diff)
downloadlinux-dev-ff05d1c4643dd4260eb699396043d7e8009c0de4.tar.xz
linux-dev-ff05d1c4643dd4260eb699396043d7e8009c0de4.zip
configfs: Zero terminate data in configfs attribute writes.
Attributes in configfs are text files. As such, most handlers expect to be able to call functions like simple_strtoul() without checking the bounds of the buffer. Change the call to zero terminate the buffer before calling the client's ->store() method. This does reduce the attribute size from PAGE_SIZE to PAGE_SIZE-1. Also, change get_zeroed_page() to alloc_page(), as we are handling the termination. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
-rw-r--r--fs/configfs/file.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index 2a7cb086e80c..d98be5e01328 100644
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -162,14 +162,17 @@ fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size
int error;
if (!buffer->page)
- buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
+ buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0);
if (!buffer->page)
return -ENOMEM;
- if (count > PAGE_SIZE)
- count = PAGE_SIZE;
+ if (count >= PAGE_SIZE)
+ count = PAGE_SIZE - 1;
error = copy_from_user(buffer->page,buf,count);
buffer->needs_read_fill = 1;
+ /* if buf is assumed to contain a string, terminate it by \0,
+ * so e.g. sscanf() can scan the string easily */
+ buffer->page[count] = 0;
return error ? -EFAULT : count;
}