From: Tristan Madani <tristan@talencesecurity.com> mainline inclusion from mainline-v7.3-rc2 commit ef248d5de4469fb6bbaf8dbe0c4c47800080d648 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19101 CVE: CVE-2026-89972 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... ---------------------------------------------------------------------- nvme_alloc_ns() error path at out_unlink_ns removes ns from the namespace head siblings list with list_del_rcu(&ns->siblings) but does not wait for SRCU readers before freeing the namespace struct. Multipath code iterates the head->list under srcu_read_lock() in nvme_find_path() and nvme_mpath_revalidate_paths(), so a concurrent reader can still hold a reference to ns when kfree(ns) runs. The normal removal path in nvme_ns_remove() correctly calls synchronize_srcu(&ns->head->srcu) after list_del_rcu() to wait for in-progress readers. Add the same grace period in the error path. Fixes: ed754e5deeb1 ("nvme: track shared namespaces") Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani <tristan@talencesecurity.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: John Garry <john.g.garry@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Keith Busch <kbusch@kernel.org> Conflicts: drivers/nvme/host/core.c [Adjusted patch context to account for missing last_path reference-counting code.] Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- drivers/nvme/host/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index cd2858916b64..caa0f1e900a0 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -4029,6 +4029,9 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid, if (list_empty(&ns->head->list)) list_del_init(&ns->head->entry); mutex_unlock(&ctrl->subsys->lock); + + /* guarantee not available in head->list */ + synchronize_srcu(&ns->head->srcu); nvme_put_ns_head(ns->head); out_cleanup_disk: blk_cleanup_disk(disk); -- 2.34.1