CVE-2026-74386nvmet-tcp: fix page fragment cache leak in error path

Official description

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: fix page fragment cache leak in error path In nvmet_tcp_alloc_queue(), when a connection is closed during the allocation process (e.g., nvmet_tcp_set_queue_sock() returns -ENOTCONN), the error handling jumps to out_destroy_sq and then to out_ida_remove without draining the page fragment cache. Although nvmet_tcp_free_cmd() is called in some error paths to release individual page fragments, the underlying page cache reference held by queue->pf_cache is never released. The first allocation using pf_cache is the call to nvmet_tcp_alloc_cmd() for queue->connect, which happens after ida_alloc() returns successfully. This results in a page leak each time a connection fails during allocation, which could lead to memory exhaustion over time if connections are repeatedly opened and closed. Fix this by calling page_frag_cache_drain() before freeing the queue structure in the out_ida_remove label.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/aadb8eb9006e192c51b499860f40765de7d55680
• https://git.kernel.org/stable/c/fc11e3f0daaadb6e600a86e54b089d4662d0a464
• https://git.kernel.org/stable/c/a43a9abc1ebf663f0aa56a729106f68dd9c77da6
• https://git.kernel.org/stable/c/ba3209704b3cd46961e4e081af5c52a780785648
• https://git.kernel.org/stable/c/5fbe83a374f09561a0f0c1f4aa021501ffd681eb
• https://git.kernel.org/stable/c/4dae393956093c807212918fd91a8fc70df15338