On Fri, 10 Dec 2010 00:02:03 +0530 Harsh Bora <harsh@xxxxxxxxxxxxxxxxxx> wrote: > Hi Al, > Any comments? > > On 12/08/2010 06:25 PM, Harsh Prateek Bora 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> > > --- > > 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; Hmm, maybe if (!(file->f_mode & FMODE_UNSIGNED_OFFSET)) return -EINVAL; if ((pos < 0) && (pos + count < pos)) return -EOVERFLOW; return 0; is a correct order ? Thanks, -Kame -- 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
