FAILED: patch "[PATCH] nvme-fabrics: fix DHCHAP secret leak on parse failure" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x afdee49a1b88ed9bb44e2b30e855297c169bcc53
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090915-fasting-saddled-14f5@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From afdee49a1b88ed9bb44e2b30e855297c169bcc53 Mon Sep 17 00:00:00 2001
From: Xu Rao <[email protected]>
Date: Thu, 13 Aug 2026 16:31:07 +0800
Subject: [PATCH] nvme-fabrics: fix DHCHAP secret leak on parse failure

nvmf_parse_options() duplicates dhchap_secret and dhchap_ctrl_secret with match_strdup() before validating the DHHC-1: representation.

If validation fails, the parser returns -EINVAL before the temporary string in p is assigned to opts->dhchap_secret or opts->dhchap_ctrl_secret. nvmf_create_ctrl() subsequently frees opts, but nvmf_free_options() cannot release the unassigned temporary string. Each rejected option therefore leaks one allocation.

This is easy to miss because valid secrets transfer ownership to opts and are freed normally, while the malformed-secret path still returns the expected -EINVAL to userspace.

With CONFIG_NVME_HOST_AUTH enabled, the leak is reachable before the required-option checks and transport lookup. No NVMe-oF target or working transport connection is required; for example, repeatedly writing

dhchap_secret=BAD

or

dhchap_ctrl_secret=BAD

to /dev/nvme-fabrics deterministically takes the leaking parse path.

Free the temporary string before leaving both validation error paths. Use kfree_sensitive() because the copied option may contain secret material even when its representation is rejected, matching the sensitive cleanup used for stored DHCHAP secrets.

index fd5abd04e080..59f823dfbbcc 100644
@@ -1028,6 +1028,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 			}
 			if (strlen(p) < 11 || strncmp(p, "DHHC-1:", 7)) {
 				pr_err("Invalid DH-CHAP secret %s\n", p);
+				kfree_sensitive(p);
 				ret = -EINVAL;
 				goto out;
 			}

@@ -1042,6 +1043,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 			}
 			if (strlen(p) < 11 || strncmp(p, "DHHC-1:", 7)) {
 				pr_err("Invalid DH-CHAP secret %s\n", p);
+				kfree_sensitive(p);
 				ret = -EINVAL;
 				goto out;
 			}

From: Xu Rao <[email protected]>

[ Upstream commit afdee49a1b88ed9bb44e2b30e855297c169bcc53 ]

nvmf_parse_options() duplicates dhchap_secret and dhchap_ctrl_secret with match_strdup() before validating the DHHC-1: representation.

If validation fails, the parser returns -EINVAL before the temporary string in p is assigned to opts->dhchap_secret or opts->dhchap_ctrl_secret. nvmf_create_ctrl() subsequently frees opts, but nvmf_free_options() cannot release the unassigned temporary string. Each rejected option therefore leaks one allocation.

This is easy to miss because valid secrets transfer ownership to opts and are freed normally, while the malformed-secret path still returns the expected -EINVAL to userspace.

With CONFIG_NVME_HOST_AUTH enabled, the leak is reachable before the required-option checks and transport lookup. No NVMe-oF target or working transport connection is required; for example, repeatedly writing

dhchap_secret=BAD

or

dhchap_ctrl_secret=BAD

to /dev/nvme-fabrics deterministically takes the leaking parse path.

Free the temporary string before leaving both validation error paths. Use kfree_sensitive() because the copied option may contain secret material even when its representation is rejected, matching the sensitive cleanup used for stored DHCHAP secrets.

---
 drivers/nvme/host/fabrics.c | 2 ++
 1 file changed, 2 insertions(+)

index fd01b86f10a4b..908961bbbe8fd 100644
@@ -952,6 +952,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 			}
 			if (strlen(p) < 11 || strncmp(p, "DHHC-1:", 7)) {
 				pr_err("Invalid DH-CHAP secret %s\n", p);
+				kfree_sensitive(p);
 				ret = -EINVAL;
 				goto out;
 			}

@@ -966,6 +967,7 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
 			}
 			if (strlen(p) < 11 || strncmp(p, "DHHC-1:", 7)) {
 				pr_err("Invalid DH-CHAP secret %s\n", p);
+				kfree_sensitive(p);
 				ret = -EINVAL;
 				goto out;
 			}

2.53.0