nvmet-rdma: handle inline data with a nonzero offset

Overview

In the Linux kernel, the following vulnerability has been resolved:

nvmet-rdma: handle inline data with a nonzero offset

nvmet_rdma_use_inline_sg() maps the host-controlled inline data offset into the per-command inline scatterlist. The bounds check admits any offset with off + len <= inline_data_size, but the mapping still assumes the data begins in the first inline page:

sg->offset = off;
sg->length = min_t(int, len, PAGE_SIZE - off);

When a port is configured with inline_data_size > PAGE_SIZE (settable up to max(SZ_16K, PAGE_SIZE)), an offset in (PAGE_SIZE, inline_data_size] makes "PAGE_SIZE - off" underflow, so sg->length is set to ~4 GiB and the block backend reads far past the first inline page. num_pages(len) also ignores the offset, so an in-bounds offset whose [off, off+len) span crosses a page boundary under-counts the scatterlist.

Map the offset properly: split it into a page index and an in-page offset, start the scatterlist at that page, and size the page count from page_off + len. Because the request scatterlist may now start at inline_sg[page_idx] rather than inline_sg[0], generalize the inline-SGL identity test in nvmet_rdma_release_rsp() to a range test; otherwise the persistent inline scatterlist is mistaken for an allocated one and nvmet_req_free_sgls() frees an inline page (and warns in free_large_kmalloc()).

Affected

• Linux >= 0d5ee2b2ab4f6776c361bc975c2323bc8b5cf349 < c2106ba1b14d644a5203bea1a50dbe25dcad713c
• Linux >= 0d5ee2b2ab4f6776c361bc975c2323bc8b5cf349 < bf8bcc1c137d54a62a428b00051fdbb13660673b
• Linux >= 0d5ee2b2ab4f6776c361bc975c2323bc8b5cf349 < 11401371152b228448a41d79c6de1c938f93049a
• Linux >= 0d5ee2b2ab4f6776c361bc975c2323bc8b5cf349 < 7c96581169c9d9a7d0726e554313acfbead6141c
• Linux >= 0d5ee2b2ab4f6776c361bc975c2323bc8b5cf349 < 42a8ea3acd883f4f210d9e54e0975b1e2292b529
• Linux >= 0d5ee2b2ab4f6776c361bc975c2323bc8b5cf349 < 2944113ad5fbcdf5d349d857c03d2a44b6de75b8
• Linux >= 0d5ee2b2ab4f6776c361bc975c2323bc8b5cf349 < 98bcdfa619150b2f41fa15bac140dbaf2584ad05
• Linux >= 0d5ee2b2ab4f6776c361bc975c2323bc8b5cf349 < 48c0162f647bb47e6084ffbc71b8f213f5e2f4f8
• Linux 4.19

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.