Linux Kernel version 3.18 to 4.16 incorrectly handles an SGIO ioctl on /dev/sg0 with dxferdirection=SGDXFERFROMDEV and an empty 6-byte cmdp. This may lead to copying up to 1000 kernel heap pages to the userspace. This has been fixed upstream in https://github.com/torvalds/linux/commit/a45b599ad808c3c982fdcdc12b0b8611c2f92824 already. The problem has limited scope, as users don't usually have permissions to access SCSI devices. On the other hand, e.g. the Nero user manual suggests doing chmod o+r+w /dev/sg*
to make the devices accessible. NOTE: third parties dispute the relevance of this report, noting that the requirement for an attacker to have both the CAPSYSADMIN and CAPSYS_RAWIO capabilities makes it "virtually impossible to exploit.