CVE-2026-72014

In the Linux kernel, the following vulnerability has been resolved:

drbd: reject data replies with an out-of-range payload size

recvdlessread() receives a PDATAREPLY from a peer into the bio of an

outstanding read request. The peer-supplied payload length reaches it as

the signed int data_size, and two peer-controlled inputs can make it

negative. With a negotiated data-integrity-alg the digest length is

subtracted first, so a reply whose payload is smaller than the digest

underflows datasize. With no integrity algorithm (the default) datasize

is assigned from the unsigned h95/h100 wire length and drbdd() never

bounds it for a payload-carrying command, so a length above INT_MAX casts

it negative; this path needs no non-default feature. The bio receive loop

then computes expect = mint(int, datasize, bv_len), which is negative,

and drbdrecvallwarn(mapped, expect) receives with a sizet of SIZE_MAX

into the first mapped page.

The sibling receive path readinblock() is not affected: it uses an

unsigned size and rejects it against DRBDMAXBIO_SIZE before receiving.

Reject a data reply whose size is negative after the optional digest

subtraction, covering both triggers.

Impact: a malicious or man-in-the-middle DRBD peer copies attacker-chosen

bytes past a bio page in the receiver, corrupting kernel memory. A node

that reads from its peer (a diskless node, or read-balancing to the peer)

is exposed in the default configuration; data-integrity-alg is not

required.