CVE-2026-52989: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers

CVE-2026-52989: nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

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

nvmet-tcp: propagate nvmet_tcp_build_pdu_iovec() errors to its callers

Currently, when nvmet_tcp_build_pdu_iovec() detects an out-of-bounds
PDU length or offset, it triggers nvmet_tcp_fatal_error(cmd->queue)
and returns early. However, because the function returns void, the
callers are entirely unaware that a fatal error has occurred and
that the cmd->recv_msg.msg_iter was left uninitialized.

Callers such as nvmet_tcp_handle_h2c_data_pdu() proceed to blindly
overwrite the queue state with queue->rcv_state = NVMET_TCP_RECV_DATA
Consequently, the socket receiving loop may attempt to read incoming
network data into the uninitialized iterator.

Fix this by shifting the error handling responsibility to the callers.

The Linux kernel CVE team has assigned CVE-2026-52989 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.1.163 with commit 1385be357e8acd09b36e026567f3a9d5c61139de and fixed in 6.1.175 with commit 3df42a854686fa06484e37ac1a3931c8e3e3453c
	Issue introduced in 6.6.124 with commit dca1a6ba0da9f472ef040525fab10fd9956db59f and fixed in 6.6.141 with commit d7c8f95f599b3b38a717d2e771c3f8c174f657c3
	Issue introduced in 6.12.70 with commit 19672ae68d52ff75347ebe2420dde1b07adca09f and fixed in 6.12.91 with commit f9204a2b78dd18374d3bcf9bf93d9021ce22de1b
	Issue introduced in 6.18.10 with commit ab200d71553bdcf4de554a5985b05b2dd606bc57 and fixed in 6.18.33 with commit c2a11441538bdbbc5aa003f190995eba93a89b88
	Issue introduced in 6.19 with commit 52a0a98549344ca20ad81a4176d68d28e3c05a5c and fixed in 7.0.10 with commit 046fa5c72d15cd8e2d592e275697ea399d8f76b0
	Issue introduced in 6.19 with commit 52a0a98549344ca20ad81a4176d68d28e3c05a5c and fixed in 7.1 with commit ea8e356acb165cb1fd75537a52e1f66e5e76c538
	Issue introduced in 5.10.250 with commit 043b4307a99f902697349128fde93b2ddde4686c
	Issue introduced in 5.15.200 with commit 42afe8ed8ad2de9c19457156244ef3e1eca94b5d

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-52989
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/nvme/target/tcp.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/3df42a854686fa06484e37ac1a3931c8e3e3453c
	https://git.kernel.org/stable/c/d7c8f95f599b3b38a717d2e771c3f8c174f657c3
	https://git.kernel.org/stable/c/f9204a2b78dd18374d3bcf9bf93d9021ce22de1b
	https://git.kernel.org/stable/c/c2a11441538bdbbc5aa003f190995eba93a89b88
	https://git.kernel.org/stable/c/046fa5c72d15cd8e2d592e275697ea399d8f76b0
	https://git.kernel.org/stable/c/ea8e356acb165cb1fd75537a52e1f66e5e76c538