Commit 9358bdb9 authored by Ivan Stepchenko's avatar Ivan Stepchenko Committed by Miquel Raynal
Browse files

mtd: fix possible integer overflow in erase_xfer() 



The expression '1 << EraseUnitSize' is evaluated in int, which causes
a negative result when shifting by 31 - the upper bound of the valid
range [10, 31], enforced by scan_header(). This leads to incorrect
extension when storing the result in 'erase->len' (uint64_t), producing
a large unexpected value.

Found by Linux Verification Center (linuxtesting.org) with Svace.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarIvan Stepchenko <sid@itb.spb.ru>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
parent d22d5f47

drivers/mtd/ftl.c

+1 −1
Original line number Diff line number Diff line
@@ -344,7 +344,7 @@ static int erase_xfer(partition_t *part, 
            return -ENOMEM;



    erase->addr = xfer->Offset;

    erase->len = 1 << part->header.EraseUnitSize;

    erase->len = 1ULL << part->header.EraseUnitSize;



    ret = mtd_erase(part->mbd.mtd, erase);

    if (!ret) {