Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts
In the Linux kernel, the following vulnerability has been resolved:
xen/privcmd: restrict usage in unprivileged domU
The Xen privcmd driver allows to issue arbitrary hypercalls from user space processes. This is normally no problem, as access is usually limited to root and the hypervisor will deny any hypercalls affecting other domains.
In case the guest is booted using secure boot, however, the privcmd driver would be enabling a root user process to modify e.g. kernel memory contents, thus breaking the secure boot feature.
The only known case where an unprivileged domU is really needing to use the privcmd driver is the case when it is acting as the device model for another guest. In this case all hypercalls issued via the privcmd driver will target that other guest.
Fortunately the privcmd driver can already be locked down to allow only hypercalls targeting a specific domain, but this mode can be activated from user land only today.
The target domain can be obtained from Xenstore, so when not running in dom0 restrict the privcmd driver to that target domain from the beginning, resolving the potential problem of breaking secure boot.
This is XSA-482
--- V2: - defer reading from Xenstore if Xenstore isn't ready yet (Jan Beulich) - wait in open() if target domain isn't known yet - issue message in case no target domain found (Jan Beulich)
In the Linux kernel, the following vulnerability has been resolved:
xen/privcmd: restrict usage in unprivileged domU
The Xen privcmd driver allows to issue arbitrary hypercalls from user space processes. This is normally no problem, as access is usually limited to root and the hypervisor will deny any hypercalls affecting other domains.
In case the guest is booted using secure boot, however, the privcmd driver would be enabling a root user process to modify e.g. kernel memory contents, thus breaking the secure boot feature.
The only known case where an unprivileged domU is really needing to use the privcmd driver is the case when it is acting as the device model for another guest. In this case all hypercalls issued via the privcmd driver will target that other guest.
Fortunately the privcmd driver can already be locked down to allow only hypercalls targeting a specific domain, but this mode can be activated from user land only today.
The target domain can be obtained from Xenstore, so when not running in dom0 restrict the privcmd driver to that target domain from the beginning, resolving the potential problem of breaking secure boot.
This is XSA-482
--- V2: - defer reading from Xenstore if Xenstore isn't ready yet (Jan Beulich) - wait in open() if target domain isn't known yet - issue message in case no target domain found (Jan Beulich)
Affected: openEuler:24.03-LTS: kernel
The Linux Kernel, the operating system core itself. Security Fix(es):
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to detect potential corrupted nid in free_nid_list
As reported, on-disk footer.ino and footer.nid is the same and out-of-range, let's add sanity check on f2fs_alloc_nid() to detect any potential corruption in free_nid_list.(CVE-2025-68315)
In the Linux kernel, the following vulnerability has been resolved:
ntfs3: Fix uninit buffer allocated by __getname()
Fix uninit errors caused after buffer allocation given to 'de'; by initializing the buffer with zeroes. The fix was found by using KMSAN.(CVE-2025-68727)
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: fix use-after-free in nf_tables_addchain()
nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_register_hook() then fails, the error path calls nft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy() with no RCU grace period in between.
This creates two use-after-free conditions:
1) Control-plane: nf_tables_dump_chains() traverses table->chains under rcu_read_lock(). A concurrent dump can still be walking the chain when the error path frees it.
2) Packet path: for NFPROTO_INET, nf_register_net_hook() briefly installs the IPv4 hook before IPv6 registration fails. Packets entering nft…
Security update for the Linux Kernel
Security update for the Linux Kernel
Affected: Ubuntu:Pro:14.04:LTS: linux, Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe and 232 more
In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: restrict usage in unprivileged domU The Xen privcmd driver allows to issue arbitrary hypercalls from user space processes. This is normally no problem, as access is usually limited to root and the hypervisor will deny any hypercalls affecting other domains. In case the guest is booted using secure boot, however, the privcmd driver would be enabling a root user process to modify e.g. kernel memory contents, thus breaking the secure boot feature. The only known case where an unprivileged domU is really needing to use the privcmd driver is the case when it is acting as the device model for another guest. In this case all hypercalls issued via the privcmd driver will target that other guest. Fortunately the privcmd driver can already be locked down to allow only hypercalls targeting a specific domain, but this mode can be activated from user land only today. The target domain can be obtained from Xenstore, so when not running in dom0 restrict the privcmd driver to that target domain from the beginning, resolving the potential problem of breaking secure boot. This is XSA-482 --- V2: - defer reading from Xenstore if Xenstore isn't ready yet (Jan Beulich) - wait in open() if target domain isn't known yet - issue message in case no target domain found (Jan Beulich)
Ein lokaler Angreifer aus einer Gast-VM kann eine Schwachstelle in Xen ausnutzen, um Sicherheitsvorkehrungen zu umgehen.