Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.5 | 6.6.103 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.16.3-1 | — |
| Debian 13 | linux | 6.12.43-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1016.20 | — |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-100.100 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-aws +1 | 6.8.0-1046.49 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1046.52 | USN-8074-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1046.53 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1047.50 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1043.48 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1030.33 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1044.44 | USN-8028-8 |
| Ubuntu 24.04 LTS | linux-intel +19 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-100.100.1 | USN-8052-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1046.49.1 | USN-8028-7 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1020.20 | — |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1043.44 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1047.51 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1023.24 | USN-8052-2 |
| Ubuntu 22.04 LTS | linux-aws-6.8 +1 | 6.8.0-1046.49~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1046.53~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1047.50~22.04.2 | USN-8031-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-100.100~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1044.44~22.04.1 | USN-8028-8 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-100.100.1~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1043.44~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2037.38 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1041.42 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1041.42~22.04.1 | USN-8028-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1046.49+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1046.52+fips1 | USN-8074-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-100.100+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1047.50+fips1 | USN-8031-2 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.22.1 | SUSE-SU-2025:4057-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.18.1 | SUSE-SU-2025:4132-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.22.1.150700.17.15.1 | SUSE-SU-2025:4057-1 |
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.52.1 | SUSE-SU-2025:03634-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.73.1.150600.12.32.1 | SUSE-SU-2025:03600-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +7 | 6.12.0-160000.6.1 | SUSE-SU-2025:21139-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21139-1 |
| SLES 16.0 | kernel-64kb +7 | 6.12.0-160000.6.1 | SUSE-SU-2025:21179-1, SUSE-SU-2025:21139-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21139-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | SUSE-SU-2025:21074-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.6.1 | SUSE-SU-2026:20560-1, SUSE-SU-2025:21074-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-35.1.21.12 | SUSE-SU-2025:20861-1 |
| SLE Micro 6.1 | kernel-rt +1 | 6.4.0-37.1 | SUSE-SU-2025:20898-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-35.1 | SUSE-SU-2025:20861-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-35.1.21.12 | SUSE-SU-2025:20851-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-37.1 | SUSE-SU-2025:20870-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-35.1 | SUSE-SU-2025:20851-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.22.1 | SUSE-SU-2025:4057-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_6 | 1-150700.1.3.1 | SUSE-SU-2025:4141-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_6 | 1-150700.15.3.1 | SUSE-SU-2025:4057-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_16 | 1-150600.1.3.1 | SUSE-SU-2025:3751-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_16 | 1-150600.13.3.1 | SUSE-SU-2025:03600-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.22.1 | SUSE-SU-2025:4141-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +3 | 6.4.0-150600.10.55.1 | SUSE-SU-2025:3751-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.6.1.160000.2.4 | openSUSE-SU-2025:20081-1 |
| openSUSE Leap 16.0 | kernel-rt +10 | 6.12.0-160000.6.1 | openSUSE-SU-2025:20081-1 |
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.73.1 | SUSE-SU-2025:03600-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.52.1 | SUSE-SU-2025:03634-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.73.1.150600.12.32.1 | SUSE-SU-2025:03600-1 |
| openSUSE Leap 15.6 | kernel-rt +3 | 6.4.0-150600.10.55.1 | SUSE-SU-2025:3751-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.104.2-1 | — |
Advisories 32
- WID-SEC-2025-2040 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8028-5 linux-aws, linux-aws-6.8, linux-gkeop, linux-nvidia, linux-nvidia-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8126-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-8 linux-ibm, linux-ibm-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-6 linux-hwe-6.8, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-1 linux-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-2 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-2 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-3 linux-gcp, linux-gke vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-1 linux, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-4 linux-aws-fips, linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-3 linux-realtime, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-7 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-2 linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-2 linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-1 linux-gcp-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- SUSE-SU-2026:20560-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- openSUSE-SU-2025:20081-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21179-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21139-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:21074-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20851-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03634-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:4141-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20861-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20870-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:03600-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20898-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:3751-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4132-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4057-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://git.kernel.org/stable/c/b47c4b7cb78b6382c6d1af0bfc0d8218e4f445cc
- https://git.kernel.org/stable/c/5661fdd218c2799001b88c17acd19f4395e4488e
- https://git.kernel.org/stable/c/673cf582fd788af12cdacfb62a6a593083542481
- https://git.kernel.org/stable/c/42ebc16d9d2563f1a1ce0f05b643ee68d54fabf8
- https://git.kernel.org/stable/c/edf82bc8150570167a33a7d54627d66614cbf841
- https://git.kernel.org/stable/c/c18646248fed07683d4cee8a8af933fc4fe83c0d