Re: [ntfs-3g-devel] [PATCH] Correct validation of multi sector transfer protected records

2016-07-27 Thread Eric Biggers
On Wed, Jul 27, 2016 at 12:20:24PM +0200, Jean-Pierre André wrote: > > Can you disambiguate the word "sector" here ? This is not > a physical sector, but an ntfs logical sector whose size > is NTFS_BLOCK_SIZE (512 bytes). This might not have been > known to the original developer, and it would be

[ntfs-3g-devel] [PATCH] Correct validation of multi sector transfer protected records

2016-07-27 Thread Eric Biggers
I found that the validation contained an off-by-one error. The expression '(u32)(usa_ofs + (usa_count * 2)) > size' used 'usa_count' after it had been decremented to skip the update sequence number entry. Consequently, the code could read out of bounds, up to two bytes past the end of the