Unverified Commit 34e6552a authored by Pavel Skripkin's avatar Pavel Skripkin Committed by Konstantin Komarov
Browse files

fs/ntfs3: Fix OOB read in ntfs_init_from_boot 



Syzbot was able to create a device which has the last sector of size
512.

After failing to boot from initial sector, reading from boot info from
offset 511 causes OOB read.

To prevent such reports add sanity check to validate if size of buffer_head
if big enough to hold ntfs3 bootinfo

Fixes: 6a4cd3ea ("fs/ntfs3: Alternative boot if primary boot is corrupted")
Reported-by: default avatar <syzbot+53ce40c8c0322c06aea5@syzkaller.appspotmail.com>
Signed-off-by: default avatarPavel Skripkin <paskripkin@gmail.com>
Signed-off-by: default avatarKonstantin Komarov <almaz.alexandrovich@paragon-software.com>
parent 8e7e27b2

fs/ntfs3/super.c

+5 −0
Original line number Diff line number Diff line
@@ -878,6 +878,11 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size, 


check_boot:

	err = -EINVAL;



	/* Corrupted image; do not read OOB */

	if (bh->b_size - sizeof(*boot) < boot_off)

		goto out;



	boot = (struct NTFS_BOOT *)Add2Ptr(bh->b_data, boot_off);



	if (memcmp(boot->system_id, "NTFS    ", sizeof("NTFS    ") - 1)) {