On Wed, 29 Apr 2015 22:14:19 -0700 "Reese Faucette" <[email protected]> wrote:
> When checking for overflow, the code in mm/mmap.c compares the first byte > *after* the end of mapped region to the start of the region instead of the > last byte of the mapped region. This prevents mapping a region which abuts > the end of physical space, as mmap() incorrectly rejects the region with > -EOVERFLOW, because pgoff + (len >> PAGE_SHIFT) will be 0, which is < pgoff. > -reese > > Reese Faucette > Cisco Systems, Inc. > > ==================================================== > --- mm/mmap.c > +++ mm/mmap.c > @@ -1241,7 +1241,7 @@ > return -ENOMEM; > > /* offset overflow? */ > - if ((pgoff + (len >> PAGE_SHIFT)) < pgoff) > + if ((pgoff + (len >> PAGE_SHIFT) - 1) < pgoff) > return -EOVERFLOW; > > /* Too many mappings? */ Looks right. Please send a Signed-off-by: for this patch, as per Documentation/SubmittingPatches, section 11. Please also let me know whether the authorship should be [email protected] or some Cisco address, as people often prefer. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
