The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0792 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2026-31502:
    In the Linux kernel, the following vulnerability has been resolved: xfs: resample the data fork mapping     after cycling ILOCK. xfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode, a data fork     mapping, and a cow fork mapping. Unfortunately, these two helpers cycle the ILOCK to grab a transaction,     which means that the mappings are stale as soon as we reacquire the ILOCK. Currently we refresh the cow     fork mapping by re-calling xfs_find_trim_cow_extent, but we don't refresh the data fork mapping     beforehand, which means that the xfs_bmap_trim_cow in that function queries the refcount btree about the     wrong physical blocks and returns an inaccurate value in *shared. If *shared is now false, the directio     write proceeds with a stale data fork mapping. Fix this by querying the data fork mapping if the sequence     counter changes across the ILOCK cycle.

    CVE-2026-53362:
    In the Linux kernel, the following vulnerability has been resolved:

    eventpoll: fix ep_remove struct eventpoll / struct file UAF

    ep_remove() (via ep_remove_file()) cleared file->f_ep under     file->f_lock but then kept using @file inside the critical section     (is_file_epoll(), hlist_del_rcu() through the head, spin_unlock).
    A concurrent __fput() taking the eventpoll_release() fastpath in     that window observed the transient NULL, skipped     eventpoll_release_file() and ran to f_op->release / file_free().

    For the epoll-watches-epoll case, f_op->release is     ep_eventpoll_release() -> ep_clear_and_put() -> ep_free(), which     kfree()s the watched struct eventpoll. Its embedded ->refs     hlist_head is exactly where epi->fllink.pprev points, so the     subsequent hlist_del_rcu()'s *pprev = next scribbles into freed     kmalloc-192 memory.

    In addition, struct file is SLAB_TYPESAFE_BY_RCU, so the slot     backing @file could be recycled by alloc_empty_file() --     reinitializing f_lock and f_ep -- while ep_remove() is still     nominally inside that lock. The upshot is an attacker-controllable     kmem_cache_free() against the wrong slab cache.

    Pin @file via epi_fget() at the top of ep_remove() and gate the     critical section on the pin succeeding. With the pin held @file     cannot reach refcount zero, which holds __fput() off and     transitively keeps the watched struct eventpoll alive across the     hlist_del_rcu() and the f_lock use, closing both UAFs.

    If the pin fails @file has already reached refcount zero and its
    __fput() is in flight. Because we bailed before clearing f_ep,     that path takes the eventpoll_release() slow path into     eventpoll_release_file() and blocks on ep->mtx until the waiter     side's ep_clear_and_put() drops it. The bailed epi's share of     ep->refcount stays intact, so the trailing ep_refcount_dec_and_test()     in ep_clear_and_put() cannot free the eventpoll out from under     eventpoll_release_file(); the orphaned epi is then cleaned up     there.

    A successful pin also proves we are not racing     eventpoll_release_file() on this epi, so drop the now-redundant     re-check of epi->dying under f_lock. The cheap lockless     READ_ONCE(epi->dying) fast-path bailout stays.

    CVE-2026-43456:
    In the Linux kernel, the following vulnerability has been resolved:

    ipv6: account for fraggap on the paged allocation path

    In __ip6_append_data(), when the paged-allocation branch is taken     (MSG_MORE / NETIF_F_SG / large fraglen), alloclen and pagedlen are     computed as

            alloclen = fragheaderlen + transhdrlen;
            pagedlen = datalen - transhdrlen;

    datalen already includes fraggap (datalen = length + fraggap). When     fraggap is non-zero, this is not the first skb and transhdrlen is zero.
    The fraggap bytes carried over from the previous skb are copied just past     the fragment headers in the new skb's linear area. The linear area is     therefore undersized by fraggap bytes while pagedlen is overstated by the     same amount, and the copy writes past skb->end into the trailing     skb_shared_info.

    An unprivileged user can trigger this via a UDPv6 socket using     MSG_MORE together with MSG_SPLICE_PAGES.

    The bad accounting was introduced by commit 773ba4fe9104 (ipv6:
    avoid partial copy for zc). Before commit ce650a166335 (udp6: Fix
    __ip6_append_data()'s handling of MSG_SPLICE_PAGES), the negative     copy value caused -EINVAL to be returned. That later commit allowed     MSG_SPLICE_PAGES to proceed in this case, making the corruption     triggerable.

    The non-paged branch sets alloclen to fraglen, which already accounts     for fraggap because datalen does. Bring the paged branch in line by     adding fraggap to alloclen and subtracting it from pagedlen.

    After this adjustment, copy no longer collapses to -fraggap on the     paged path, so remove the stale comment describing that old arithmetic.
    Since a negative copy is no longer expected for a valid MSG_SPLICE_PAGES     case, remove the MSG_SPLICE_PAGES exception from the negative copy check.

    CVE-2026-46242:
    In the Linux kernel, the following vulnerability has been resolved:

    bonding: fix type confusion in bond_setup_by_slave()

    kernel BUG at net/core/skbuff.c:2306!     Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI     RIP: 0010:pskb_expand_head+0xa08/0xfe0 net/core/skbuff.c:2306     RSP: 0018:ffffc90004aff760 EFLAGS: 00010293     RAX: 0000000000000000 RBX: ffff88807e3c8780 RCX: ffffffff89593e0e     RDX: ffff88807b7c4900 RSI: ffffffff89594747 RDI: ffff88807b7c4900     RBP: 0000000000000820 R08: 0000000000000005 R09: 0000000000000000     R10: 00000000961a63e0 R11: 0000000000000000 R12: ffff88807e3c8780     R13: 00000000961a6560 R14: dffffc0000000000 R15: 00000000961a63e0     CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033     CR2: 00007fe1a0ed8df0 CR3: 000000002d816000 CR4: 00000000003526f0     Call Trace:
     <TASK>      ipgre_header+0xdd/0x540 net/ipv4/ip_gre.c:900      dev_hard_header include/linux/netdevice.h:3439 [inline]      packet_snd net/packet/af_packet.c:3028 [inline]      packet_sendmsg+0x3ae5/0x53c0 net/packet/af_packet.c:3108      sock_sendmsg_nosec net/socket.c:727 [inline]
     __sock_sendmsg net/socket.c:742 [inline]
     ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
     ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
     __sys_sendmsg+0x170/0x220 net/socket.c:2678      do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]      do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94      entry_SYSCALL_64_after_hwframe+0x77/0x7f     RIP: 0033:0x7fe1a0e6c1a9

    When a non-Ethernet device (e.g. GRE tunnel) is enslaved to a bond,     bond_setup_by_slave() directly copies the slave's header_ops to the     bond device:

      bond_dev->header_ops = slave_dev->header_ops;

    This causes a type confusion when dev_hard_header() is later called     on the bond device. Functions like ipgre_header(), ip6gre_header(),all use     netdev_priv(dev) to access their device-specific private data. When     called with the bond device, netdev_priv() returns the bond's private     data (struct bonding) instead of the expected type (e.g. struct     ip_tunnel), leading to garbage values being read and kernel crashes.

    Fix this by introducing bond_header_ops with wrapper functions that     delegate to the active slave's header_ops using the slave's own     device. This ensures netdev_priv() in the slave's header functions     always receives the correct device.

    The fix is placed in the bonding driver rather than individual device     drivers, as the root cause is bond blindly inheriting header_ops from     the slave without considering that these callbacks expect a specific     netdev_priv() layout.

    The type confusion can be observed by adding a printk in     ipgre_header() and running the following commands:

      ip link add dummy0 type dummy       ip addr add 10.0.0.1/24 dev dummy0       ip link set dummy0 up       ip link add gre1 type gre local 10.0.0.1       ip link add bond1 type bond mode active-backup       ip link set gre1 master bond1       ip link set gre1 up       ip link set bond1 up       ip addr add fe80::1/64 dev bond1

    CVE-2026-23451:
    In the Linux kernel, the following vulnerability has been resolved:

    team: fix header_ops type confusion with non-Ethernet ports

    Similar to commit 950803f72547 (bonding: fix type confusion in     bond_setup_by_slave()) team has the same class of header_ops type     confusion.

    For non-Ethernet ports, team_setup_by_port() copies port_dev->header_ops     directly. When the team device later calls dev_hard_header() or     dev_parse_header(), these callbacks can run with the team net_device     instead of the real lower device, so netdev_priv(dev) is interpreted as     the wrong private type and can crash.

    The syzbot report shows a crash in bond_header_create(), but the root     cause is in team: the topology is gre -> bond -> team, and team calls     the inherited header_ops with its own net_device instead of the lower     device, so bond_header_create() receives a team device and interprets     netdev_priv() as bonding private data, causing a type confusion crash.

    Fix this by introducing team header_ops wrappers for create/parse,     selecting a team port under RCU, and calling the lower device callbacks     with port->dev, so each callback always sees the correct net_device     context.

    Also pass the selected lower device to the lower parse callback, so     recursion is bounded in stacked non-Ethernet topologies and parse     callbacks always run with the correct device context.

    CVE-2026-64600:
    In the Linux kernel, the following vulnerability has been resolved:

    bonding: prevent potential infinite loop in bond_header_parse()

    bond_header_parse() can loop if a stack of two bonding devices is setup,     because skb->dev always points to the hierarchy top.

    Add new const struct net_device *dev parameter to     (struct header_ops)->parse() method to make sure the recursion     is bounded, and that the final leaf parse method is called.

    CVE-2026-64531:
    In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: reject oversized     nested action attrs. Open vSwitch stores generated flow actions as nlattrs, whose nla_len field is u16. An     oversized generated container can be closed with a truncated nla_len, causing later dump or teardown to     walk a structurally different stream than the one that was validated. An oversized nested CLONE/CT action     may cause subsequent bytes to be interpreted as independent actions.

    CVE-2026-64564:
    In the Linux kernel, the following vulnerability has been resolved: 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. For an ASCONF located through its Address Parameter, that cached transport     corresponds to the Address Parameter, which need not be the packet's source address. A single ASCONF can     carry DEL-IP for the cached transport followed by a wildcard DEL-IP, causing use-after-free of the freed     transport.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

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TencentOS Server 4: kernel (TSSA-2026:0792)

critical Nessus Plugin ID 333128

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Version 1.2 Aug 10, 2026, 9:45 AM CVSS metrics ("CVSSv2 score" set to 10.0) CVSS metrics ("CVSSv2 vector" set to "CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C") CVSS metrics ("CVSSv3 score" set to 9.8) CVSS metrics ("CVSSv3 vector" set to "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H") CVSSv3 score source (changed from "CVE-2026-64600" to none) Plugin Feed: 202608100945
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