Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: Do not WARN on remotely-controlled oversized SGL allocations When fuzzing the nvme target code, I tripped a kernel warning in nvmet_tcp_map_data() because the length passed into the allocator is controlled by the remote initiator. A remote initiator that sends a command with an SGL claiming a huge number, can create a scatterlist and iovec allocation of over 1 million entries, which causes the backing kmalloc call to exceed MAX_PAGE_ORDER and then the page allocator will trip on a WARN_ON_ONCE_GFP() message: WARNING: mm/page_alloc.c:5280 __alloc_frozen_pages_noprof Workqueue: nvmet_tcp_wq nvmet_tcp_io_work ... sgl_alloc_order nvmet_tcp_map_data nvmet_tcp_try_recv_pdu As it's never good to trip a kernel warning remotely due to many systems having panic-on-warn enabled, let's silence it by just add GFP_NOWARN to the allocation flags.

Affected versions

Linux: 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before 8d01f0d0e96485e39ad89b859ef85e1dc3020465 (git); 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before 7b6a54d4e7b0da423c2b53ed293fd36b16c0b19e (git); 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before e7077e6c45423dd2bb7de7b5fc4b018a8e6c4741 (git); 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before 86cc450022473c4a29b43a09f3ec22a9ef566dac (git); 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before c509f20be1cabda3087810bb2d658d66b3f31f35 (git); 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before 9c95f7e66c62ee6c6abedcf1c04311f430ff5833 (git); 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before 7fd6da0f28932442b51658bac4ff55565ca9b377 (git); 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before 9b770e40bc00381e5ebf53653de5776773415be3 (git); 872d26a391da92ed8f0c0f5cb5fef428067b7f30 through before 737a3b535247226f6e1a7988fd9d6e63e7d6fc71 (git); 5.0 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.