CyberSecBulletin
CVE-2022-49865NVD status: Analyzed

Linux: Missing Initialization of Resource

Published Updated By the CyberSecBulletin desk

CVE-2022-49865 is a high-severity missing initialization of resource vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 568a47ff756f913e8b374c2af9d22cd2c772c744, 0f85b7ae7c4b5d7b4bbf7ac653a733c181a8a2bf, 6d26d0587abccb9835382a0b53faa7b9b1cd83e3 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.22% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 568a47ff756f913e8b374c2af9d22cd2c772c744 or 0f85b7ae7c4b5d7b4bbf7ac653a733c181a8a2bf or 6d26d0587abccb9835382a0b53faa7b9b1cd83e3 or 58cd7fdc8c1e6c7873acc08f190069fed88d1c12, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.9.334 or 4.14.300 or 4.19.267 or 5.4.225, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux2a8cc6c89039e0530a3335954253b76ed0f9339a up to, but not including, 568a47ff756f913e8b374c2af9d22cd2c772c744; 2a8cc6c89039e0530a3335954253b76ed0f9339a up to, but not including, 0f85b7ae7c4b5d7b4bbf7ac653a733c181a8a2bf; 2a8cc6c89039e0530a3335954253b76ed0f9339a up to, but not including, 6d26d0587abccb9835382a0b53faa7b9b1cd83e3; 2a8cc6c89039e0530a3335954253b76ed0f9339a up to, but not including, 58cd7fdc8c1e6c7873acc08f190069fed88d1c12; 2a8cc6c89039e0530a3335954253b76ed0f9339a up to, but not including, a033b86c7f7621fde31f0364af8986f43b44914f; 2a8cc6c89039e0530a3335954253b76ed0f9339a up to, but not including, 2acb2779b147decd300c117683d5a32ce61c75d6; 2a8cc6c89039e0530a3335954253b76ed0f9339a up to, but not including, 49e92ba5ecd7d72ba369dde2ccff738edd028a47; 2a8cc6c89039e0530a3335954253b76ed0f9339a up to, but not including, c23fb2c82267638f9d206cb96bb93e1f93ad7828; and 1 more ranges568a47ff756f913e8b374c2af9d22cd2c772c744, 0f85b7ae7c4b5d7b4bbf7ac653a733c181a8a2bf, 6d26d0587abccb9835382a0b53faa7b9b1cd83e3, 58cd7fdc8c1e6c7873acc08f190069fed88d1c12, a033b86c7f7621fde31f0364af8986f43b44914f, 2acb2779b147decd300c117683d5a32ce61c75d6
LinuxLinux Kernel2.6.25 up to, but not including, 4.9.334; 4.10 up to, but not including, 4.14.300; 4.15 up to, but not including, 4.19.267; 4.20 up to, but not including, 5.4.225; 5.5 up to, but not including, 5.10.155; 5.11 up to, but not including, 5.15.79; 5.16 up to, but not including, 6.0.9; 6.14.9.334, 4.14.300, 4.19.267, 5.4.225, 5.10.155, 5.15.79

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: ipv6: addrlabel: fix infoleak when sending struct ifaddrlblmsg to network When copying a `struct ifaddrlblmsg` to the network, __ifal_reserved remained uninitialized, resulting in a 1-byte infoleak: BUG: KMSAN: kernel-network-infoleak in __netdev_start_xmit ./include/linux/netdevice.h:4841 __netdev_start_xmit ./include/linux/netdevice.h:4841 netdev_start_xmit ./include/linux/netdevice.h:4857 xmit_one net/core/dev.c:3590 dev_hard_start_xmit+0x1dc/0x800 net/core/dev.c:3606 __dev_queue_xmit+0x17e8/0x4350 net/core/dev.c:4256 dev_queue_xmit ./include/linux/netdevice.h:3009 __netlink_deliver_tap_skb net/netlink/af_netlink.c:307 __netlink_deliver_tap+0x728/0xad0 net/netlink/af_netlink.c:325 netlink_deliver_tap net/netlink/af_netlink.c:338 __netlink_sendskb net/netlink/af_netlink.c:1263 netlink_sendskb+0x1d9/0x200 net/netlink/af_netlink.c:1272 netlink_unicast+0x56d/0xf50 net/netlink/af_netlink.c:1360 nlmsg_unicast ./include/net/netlink.h:1061 rtnl_unicast+0x5a/0x80 net/core/rtnetlink.c:758 ip6addrlbl_get+0xfad/0x10f0 net/ipv6/addrlabel.c:628 rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082 ... Uninit was created at: slab_post_alloc_hook+0x118/0xb00 mm/slab.h:742 slab_alloc_node mm/slub.c:3398 __kmem_cache_alloc_node+0x4f2/0x930 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:954 __kmalloc_node_track_caller+0x117/0x3d0 mm/slab_common.c:975 kmalloc_reserve net/core/skbuff.c:437 __alloc_skb+0x27a/0xab0 net/core/skbuff.c:509 alloc_skb ./include/linux/skbuff.h:1267 nlmsg_new ./include/net/netlink.h:964 ip6addrlbl_get+0x490/0x10f0 net/ipv6/addrlabel.c:608 rtnetlink_rcv_msg+0xb33/0x1570 net/core/rtnetlink.c:6082 netlink_rcv_skb+0x299/0x550 net/netlink/af_netlink.c:2540 rtnetlink_rcv+0x26/0x30 net/core/rtnetlink.c:6109 netlink_unicast_kernel net/netlink/af_netlink.c:1319 netlink_unicast+0x9ab/0xf50 net/netlink/af_netlink.c:1345 netlink_sendmsg+0xebc/0x10f0 net/netlink/af_netlink.c:1921 ... This patch ensures that the reserved field is always initialized.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Initialization of Resource

The product does not initialize a critical resource.

How developers prevent this class of flaw

  • Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all specified steps.
  • Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
  • Avoid race conditions (CWE-362) during initialization routines.

More Missing Initialization of Resource vulnerabilities (CWE-909)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Missing Initialization of Resource vulnerabilities

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