DEBIAN-CVE-2025-39758
- Source
- https://security-tracker.debian.org/tracker/CVE-2025-39758
- Import Source
- https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-39758.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/DEBIAN-CVE-2025-39758
- Upstream
- Published
- 2025-09-11T17:15:39Z
- Modified
- 2026-08-27T23:05:31Z
- Severity
-
- 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
In the Linux kernel, the following vulnerability has been resolved: RDMA/siw: Fix the sendmsg byte count in siw_tcp_sendpages Ever since commit c2ff29e99a76 ("siw: Inline do_tcp_sendpages()"), we have been doing this: static int siw_tcp_sendpages(struct socket *s, struct page *page, int offset, size_t size) [...] / Calculate the number of bytes we need to push, for this page * specifically / size_t bytes = min_t(size_t, PAGE_SIZE - offset, size); / If we can't splice it, then copy it in, as normal / if (!sendpage_ok(page[i])) msg.msg_flags &= ~MSG_SPLICE_PAGES; / Set the bvec pointing to the page, with len $bytes / bvec_set_page(&bvec, page[i], bytes, offset); / Set the iter to $size, aka the size of the whole sendpages (!!!) / iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size); try_page_again: lock_sock(sk); / Sendmsg with $size size (!!!) / rv = tcp_sendmsg_locked(sk, &msg, size); This means we've been sending oversized iov_iters and tcp_sendmsg calls for a while. This has a been a benign bug because sendpage_ok() always returned true. With the recent slab allocator changes being slowly introduced into next (that disallow sendpage on large kmalloc allocations), we have recently hit out-of-bounds crashes, due to slight differences in iov_iter behavior between the MSG_SPLICE_PAGES and "regular" copy paths: (MSG_SPLICE_PAGES) skb_splice_from_iter iov_iter_extract_pages iov_iter_extract_bvec_pages uses i->nr_segs to correctly stop in its tracks before OoB'ing everywhere skb_splice_from_iter gets a "short" read (!MSG_SPLICE_PAGES) skb_copy_to_page_nocache copy=iov_iter_count [...] copy_from_iter / this doesn't help */ if (unlikely(iter->count < len)) len = iter->count; iterate_bvec ... and we run off the bvecs Fix this by properly setting the iov_iter's byte count, plus sending the correct byte count to tcp_sendmsg_locked.
- References
Affected packages
Debian:13 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source&distro=trixie
Debian:14 / linux
Package
- Name
- linux
- Purl
- pkg:deb/debian/linux?arch=source&distro=forky
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affectedFixed6.16.3-1