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Upstream linux-hardened tag v7.1.6-hardened1 available #42

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opened 2026-08-04 00:00:58 +00:00 by unredacted_bot · 2 comments

unredacted_bot commented

2026-08-04 00:00:58 +00:00

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Upstream tag: v7.1.6-hardened1
Local newest PUBLISHED: v7.1.5-hardened1

Stuck release: tag v7.1.6-hardened1 exists but releases/v7.1.6-hardened1/manifest.json does not — its build failed, or publish.yml was never dispatched for it. Resolve that before cutting a new tag.

CVEs reported fixed in 7.1.6 since 7.1.5 (source: kernel.org CVE project).

Severity = Red Hat's rating (best-effort; the kernel CNA publishes no CVSS), not the project's own. List as of 2026-08-04T07:00Z — the feed can lag, so re-check vulns.git before building.

CVE-2026-64561 — KVM: x86: Check for invalid/obsolete root *after* making MMU pages available

Check for a "stale" page fault, i.e. for an invalid and/or obsolete root,
after making MMU pages available for the shadow MMU.  If reclaiming shadow
pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to
map memory into an invalid root.  On its own, populating an invalid root is
"fine", but because child shadow pages inherit their parent's role, any
children created during the map/fetch will be created as invalid pages,
thus violating KVM's invariant that invalid pages are never on the list of
active MMU pages.

Note, the underlying flaw has existed since KVM first started tracking
invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root
pagetables"), but the true badness only came along in 2020 (Linux 5.9)
with the invariant that invalid shadow pages can't be on the list of
active pages.

Note #2, inheriting role.invalid when creating child shadow pages is also
far from ideal; that flaw will be addressed separately.

CVE-2026-64562 — KVM: nVMX: Hide shadow VMCS right after VMCLEAR

free_nested() frees the shadow VMCS while vmcs01 still points to it. But
because it is asynchronous with respect to loaded_vmcs_clear(), the vCPU
might migrate before the pointer is cleared and __loaded_vmcs_clear()
may then execute VMCLEAR.

The VMCS needs to stay attached until its explicit VMCLEAR completes, but
then it can be hidden and the page safely freed.

CVE-2026-64563 — rhashtable: clear stale iter->p on table restart

rhashtable_walk_start_check() has two restart paths when resuming a walk.
When iter->walker.tbl is valid, it re-validates iter->p against the table
and sets iter->p = NULL if the object is gone.  When iter->walker.tbl is
NULL (table was freed during resize), it resets slot and skip but forgets
to clear iter->p.

rhashtable_walk_next() then dereferences the stale iter->p, reading
freed memory.  This is a use-after-free.

Any caller that does multi-fragment rhashtable walks across
walk_stop/walk_start boundaries is affected.  Concrete cases include
netlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC
(tipc_nl_sk_walk in net/tipc/socket.c).

Crash stack (netlink_diag):
  BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0
  Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080)
  Call Trace:
   rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016)
   __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122)
…

CVE-2026-64564 — sctp: don't free the ASCONF's own transport in DEL-IP processing

sctp_process_asconf() caches the transport the ASCONF chunk is processed
against in asconf->transport (== chunk->transport, set once in sctp_rcv()).
For an ASCONF located through its Address Parameter by
__sctp_rcv_asconf_lookup(), that cached transport corresponds to the
Address Parameter, which need not be the packet's source address.

sctp_process_asconf_param() rejects a DEL-IP for the packet source address
(ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf->transport.
A single ASCONF can therefore carry, in order:

    [Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0]

where L differs from the source. The DEL-IP for L passes the D8 check and
calls sctp_assoc_rm_peer() on the transport that asconf->transport still
points at, freeing it (RCU-deferred). The following wildcard DEL-IP then
reuses the now-dangling asconf->transport in sctp_assoc_set_primary() and
sctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed
transport (->ipaddr, ->state) and plants the dangling pointer into
asoc->peer.primary_path / active_path, and del_nonprimary_peers(), keeping
only the pointer that is no longer on the list, removes every real
…

Action: review the upstream signature, then tag from an up-to-date
main and push — the tag push triggers build-kernel.yml.

git switch main && git pull --ff-only   # do NOT skip
git tag v7.1.6-hardened1
git push origin v7.1.6-hardened1

The pull is load-bearing. Seed-bump merges and publish: commits
land on main continuously between builds, so a tag cut from a
stale checkout builds an old seed pin and silently ships that config.
If you already pushed a stale tag, drop it on both sides
(git push origin :refs/tags/v7.1.6-hardened1 then
git tag -d v7.1.6-hardened1), pull, and re-tag.

See docs/users/cve-policy.md for the SLA.

Upstream tag: v7.1.6-hardened1 Local newest PUBLISHED: v7.1.5-hardened1 **Stuck release:** tag `v7.1.6-hardened1` exists but `releases/v7.1.6-hardened1/manifest.json` does not — its build failed, or `publish.yml` was never dispatched for it. Resolve that before cutting a new tag. **CVEs reported fixed in `7.1.6` since `7.1.5`** (source: kernel.org CVE project). _Severity = Red Hat's rating (best-effort; the kernel CNA publishes no CVSS), not the project's own. List as of 2026-08-04T07:00Z — the feed can lag, so re-check vulns.git before building._ <details><summary>CVE-2026-64561 — KVM: x86: Check for invalid/obsolete root *after* making MMU pages available</summary> ```text Check for a "stale" page fault, i.e. for an invalid and/or obsolete root, after making MMU pages available for the shadow MMU. If reclaiming shadow pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to map memory into an invalid root. On its own, populating an invalid root is "fine", but because child shadow pages inherit their parent's role, any children created during the map/fetch will be created as invalid pages, thus violating KVM's invariant that invalid pages are never on the list of active MMU pages. Note, the underlying flaw has existed since KVM first started tracking invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root pagetables"), but the true badness only came along in 2020 (Linux 5.9) with the invariant that invalid shadow pages can't be on the list of active pages. Note #2, inheriting role.invalid when creating child shadow pages is also far from ideal; that flaw will be addressed separately. ``` </details> <details><summary>CVE-2026-64562 — KVM: nVMX: Hide shadow VMCS right after VMCLEAR</summary> ```text free_nested() frees the shadow VMCS while vmcs01 still points to it. But because it is asynchronous with respect to loaded_vmcs_clear(), the vCPU might migrate before the pointer is cleared and __loaded_vmcs_clear() may then execute VMCLEAR. The VMCS needs to stay attached until its explicit VMCLEAR completes, but then it can be hidden and the page safely freed. ``` </details> <details><summary>CVE-2026-64563 — rhashtable: clear stale iter->p on table restart</summary> ```text rhashtable_walk_start_check() has two restart paths when resuming a walk. When iter->walker.tbl is valid, it re-validates iter->p against the table and sets iter->p = NULL if the object is gone. When iter->walker.tbl is NULL (table was freed during resize), it resets slot and skip but forgets to clear iter->p. rhashtable_walk_next() then dereferences the stale iter->p, reading freed memory. This is a use-after-free. Any caller that does multi-fragment rhashtable walks across walk_stop/walk_start boundaries is affected. Concrete cases include netlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC (tipc_nl_sk_walk in net/tipc/socket.c). Crash stack (netlink_diag): BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0 Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080) Call Trace: rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016) __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122) … ``` </details> <details><summary>CVE-2026-64564 — sctp: don't free the ASCONF's own transport in DEL-IP processing</summary> ```text sctp_process_asconf() caches the transport the ASCONF chunk is processed against in asconf->transport (== chunk->transport, set once in sctp_rcv()). For an ASCONF located through its Address Parameter by __sctp_rcv_asconf_lookup(), that cached transport corresponds to the Address Parameter, which need not be the packet's source address. sctp_process_asconf_param() rejects a DEL-IP for the packet source address (ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf->transport. A single ASCONF can therefore carry, in order: [Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0] where L differs from the source. The DEL-IP for L passes the D8 check and calls sctp_assoc_rm_peer() on the transport that asconf->transport still points at, freeing it (RCU-deferred). The following wildcard DEL-IP then reuses the now-dangling asconf->transport in sctp_assoc_set_primary() and sctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed transport (->ipaddr, ->state) and plants the dangling pointer into asoc->peer.primary_path / active_path, and del_nonprimary_peers(), keeping only the pointer that is no longer on the list, removes every real … ``` </details> Action: review the upstream signature, then tag from an up-to-date `main` and push — the tag push triggers build-kernel.yml. ``` git switch main && git pull --ff-only # do NOT skip git tag v7.1.6-hardened1 git push origin v7.1.6-hardened1 ``` The pull is load-bearing. Seed-bump merges and `publish:` commits land on `main` continuously between builds, so a tag cut from a stale checkout builds an old seed pin and silently ships that config. If you already pushed a stale tag, drop it on both sides (`git push origin :refs/tags/v7.1.6-hardened1` then `git tag -d v7.1.6-hardened1`), pull, and re-tag. See docs/users/cve-policy.md for the SLA.

unredacted_bot commented

2026-08-04 07:00:57 +00:00

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Owner

CVE list refreshed from the kernel.org feed — now 4 CVE(s) recorded fixed in this release.

Newly listed since the last update:

CVE-2026-64561
CVE-2026-64562
CVE-2026-64563
CVE-2026-64564

CVE list refreshed from the kernel.org feed — now 4 CVE(s) recorded fixed in this release. Newly listed since the last update: - CVE-2026-64561 - CVE-2026-64562 - CVE-2026-64563 - CVE-2026-64564

zach commented

2026-08-04 20:29:59 +00:00

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Released

zach closed this issue

2026-08-04 20:29:59 +00:00

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