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. > --- > 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 > > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
