Commit eee2d2e6 authored by Ritesh Harjani (IBM)'s avatar Ritesh Harjani (IBM)
Browse files

iomap: Fix possible overflow condition in iomap_write_delalloc_scan 



folio_next_index() returns an unsigned long value which left shifted
by PAGE_SHIFT could possibly cause an overflow on 32-bit system. Instead
use folio_pos(folio) + folio_size(folio), which does this correctly.

Suggested-by: default avatarMatthew Wilcox <willy@infradead.org>
Signed-off-by: default avatarRitesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
parent cc86181a

fs/iomap/buffered-io.c

+1 −1
Original line number Diff line number Diff line
@@ -934,7 +934,7 @@ static int iomap_write_delalloc_scan(struct inode *inode, 
			 * the end of this data range, not the end of the folio.

			 */

			*punch_start_byte = min_t(loff_t, end_byte,

					folio_next_index(folio) << PAGE_SHIFT);

					folio_pos(folio) + folio_size(folio));

		}



		/* move offset to start of next folio in range */