On Tue, Oct 03, 2017 at 07:31:10PM +0200, Goffredo Baroncelli wrote: > From: Goffredo Baroncelli <kreijack@xxxxxxxxx> > > Jean-Denis Girard noticed commit c821e7f3 "pass bytes to > btrfs_bio_alloc" (https://patchwork.kernel.org/patch/9763081/) introduces a > regression on 32 bit machines. > When CONFIG_LBDAF is _not_ defined (CONFIG_LBDAF == Support for large > (2TB+) block devices and files) sector_t is 32 bit on 32bit machines. > > In the function submit_extent_page, 'sector' (which is sector_t type) is > multiplied by 512 to convert it from sectors to bytes, leading to an > overflow when the disk is bigger than 4GB (!). That's not good. There are some known typedefs that hide the 32bit/64bit differences but the LBDAF and sector_t is new to me. Thanks for the report and fix, I'll get it to linus/master tree in the next batch so it can go to stable tree. I've seen sector_t used in places where it is not necessary so I'll try to minimize the usage and more surprises from the << 9 shifts. Reviewed-by: David Sterba <dsterba@xxxxxxxx> Fixes: c821e7f3 ("btrfs: pass bytes to btrfs_bio_alloc") CC: stable@xxxxxxxxxxxxxxx # 4.13+ -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
