On 12/10/2010 01:48 PM, KAMEZAWA Hiroyuki wrote:
On Wed, 8 Dec 2010 18:25:00 +0530
Harsh Prateek Bora<harsh@xxxxxxxxxxxxxxxxxx> wrote:
The existing code causes the if condition to pass when it should fail
on a *64-bit kernel* because of implicit data type conversions. It can
be observed by passing pos = -1 and count = some positive number.
This results in function returning EOVERFLOW instead of EINVAL.
With this patch, the function returns EINVAL when pos is -1 and count
is a positive number. This can be tested by calling sendfile with
offset = -1 and count = some positive number on a 64-bit kernel.
Signed-off-by: Harsh Prateek Bora<harsh@xxxxxxxxxxxxxxxxxx>
Acked-by: KAMEZAWA Hiroyuki<kamezawa.hiroyu@xxxxxxxxxxxxxx>
I'm sorry for annoying you.
Oh, but I am not annoyed, .. Thanks for the ack though ! :)
---
fs/read_write.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 431a0ed..a8eabd4 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -38,7 +38,7 @@ __negative_fpos_check(struct file *file, loff_t pos, size_t count)
* pos or pos+count is negative here, check overflow.
* too big "count" will be caught in rw_verify_area().
*/
- if ((pos< 0)&& (pos + count< pos))
+ if ((pos< 0)&& ( (loff_t) (pos + count)< pos))
return -EOVERFLOW;
if (file->f_mode& FMODE_UNSIGNED_OFFSET)
return 0;
--
1.7.1.1
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