In the Linux kernel, the following vulnerability has been resolved: nfsd: don't replace page in rq_pages if it's a continuation of last page The splice read calls nfsd_splice_actor to put the pages containing file data into the svc_rqst->rq_pages array. It's possible however to get a splice result that only has a partial page at the end, if (e.g.) the filesystem hands back a short read that doesn't cover the whole page. nfsd_splice_actor will plop the partial page into its rq_pages array and return. Then later, when nfsd_splice_actor is called again, the remainder of the page may end up being filled out. At this point, nfsd_splice_actor will put the page into the array _again_ corrupting the reply. If this is done enough times, rq_next_page will overrun the array and corrupt the trailing fields -- the rq_respages and rq_next_page pointers themselves. If we've already added the page to the array in the last pass, don't add it to the array a second time when dealing with a splice continuation. This was originally handled properly in nfsd_splice_actor, but commit 91e23b1c3982 ("NFSD: Clean up nfsd_splice_actor()") removed the check for it.
2025-05-02T16:15:27.310
2025-11-12T21:08:12.057
Analyzed
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSSv3.1: 5.5 (MEDIUM)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | linux | linux_kernel | < 6.1.22 | Yes |
| Operating System | linux | linux_kernel | < 6.2.9 | Yes |
| Operating System | linux | linux_kernel | 6.3 | Yes |
| Operating System | linux | linux_kernel | 6.3 | Yes |
| Operating System | linux | linux_kernel | 6.3 | Yes |