From: Shivam Kumar <kumar.shivam43666@gmail.com> mainline inclusion from mainline-v6.19-rc6 commit 32b63acd78f577b332d976aa06b56e70d054cbba category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13509 CVE: CVE-2026-22998 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------ 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: 1. H2C_DATA PDU sent before CONNECT → both pointers NULL 2. H2C_DATA PDU for READ command → cmd->req.sg allocated, cmd->iov NULL 3. 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 Fixes: efa56305908b ("nvmet-tcp: Fix a kernel panic when host sends an invalid H2C PDU length") Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Shivam Kumar <kumar.shivam43666@gmail.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Zheng Qixing <zhengqixing@huawei.com> --- drivers/nvme/target/tcp.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c index 6975b2a054e0..3bdff81eb3af 100644 --- a/drivers/nvme/target/tcp.c +++ b/drivers/nvme/target/tcp.c @@ -995,6 +995,18 @@ static int nvmet_tcp_handle_h2c_data_pdu(struct nvmet_tcp_queue *queue) pr_err("H2CData PDU len %u is invalid\n", cmd->pdu_len); goto err_proto; } + /* + * Ensure command data structures are initialized. We must check both + * cmd->req.sg and cmd->iov because they can have different NULL states: + * - Uninitialized commands: both NULL + * - READ commands: cmd->req.sg allocated, cmd->iov NULL + * - WRITE commands: both allocated + */ + if (unlikely(!cmd->req.sg || !cmd->iov)) { + pr_err("queue %d: H2CData PDU received for invalid command state (ttag %u)\n", + queue->idx, data->ttag); + goto err_proto; + } cmd->pdu_recv = 0; nvmet_tcp_build_pdu_iovec(cmd); queue->cmd = cmd; -- 2.39.2