nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec
Summary
nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
nvme-tcp: fix NULL pointer dereferences in nvmet_tcp_build_pdu_iovec
Commit efa56305908b ("nvmet-tcp: Fix a kernel panic when host sends an invalid H2C PDU length")
added ttag bounds checking and data_offset
validation in nvmet_tcp_handle_h2c_data_pdu(), but it did not validate
whether the command's data structures (cmd->req.sg and cmd->iov) have
been properly initialized before processing H2C_DATA PDUs.
The nvmet_tcp_build_pdu_iovec() function dereferences these pointers
without NULL checks. This can be triggered by sending H2C_DATA PDU
immediately after the ICREQ/ICRESP handshake, before
sending a CONNECT command or NVMe write command.
Attack vectors that trigger NULL pointer dereferences:
- H2C_DATA PDU sent before CONNECT → both pointers NULL
- H2C_DATA PDU for READ command → cmd->req.sg allocated, cmd->iov NULL
- H2C_DATA PDU for uninitialized command slot → both pointers NULL
The fix validates both cmd->req.sg and cmd->iov before calling
nvmet_tcp_build_pdu_iovec(). Both checks are required because:
- Uninitialized commands: both NULL
- READ commands: cmd->req.sg allocated, cmd->iov NULL
- WRITE commands: both allocated
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-22998 linux-lts Fixed in: 6.1.163-r0
- Debian DEBIAN-CVE-2026-22998 linux Fixed in: 5.10.249-1
- Ubuntu UBUNTU-CVE-2026-22998 linux-hwe-edge
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org