CyberSecBulletin
CVE-2022-48855NVD status: Modified

Linux: Missing Release of Memory after Effective Lifetime

Published Updated By the CyberSecBulletin desk

CVE-2022-48855 is a high-severity missing release of memory after effective lifetime 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 3fc0fd724d199e061432b66a8d85b7d48fe485f7, 41a2864cf719c17294f417726edd411643462ab8, 2d8fa3fdf4542a2174a72d92018f488d65d848c5 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 0.23% 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 3fc0fd724d199e061432b66a8d85b7d48fe485f7 or 41a2864cf719c17294f417726edd411643462ab8 or 2d8fa3fdf4542a2174a72d92018f488d65d848c5 or bbf59d7ae558940cfa2b36a287fd1e88d83f89f8, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.9.307 or 4.14.272 or 4.19.235 or 5.4.185, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux8f840e47f190cbe61a96945c13e9551048d42cef up to, but not including, 3fc0fd724d199e061432b66a8d85b7d48fe485f7; 8f840e47f190cbe61a96945c13e9551048d42cef up to, but not including, 41a2864cf719c17294f417726edd411643462ab8; 8f840e47f190cbe61a96945c13e9551048d42cef up to, but not including, 2d8fa3fdf4542a2174a72d92018f488d65d848c5; 8f840e47f190cbe61a96945c13e9551048d42cef up to, but not including, bbf59d7ae558940cfa2b36a287fd1e88d83f89f8; 8f840e47f190cbe61a96945c13e9551048d42cef up to, but not including, b7e4d9ba2ddb78801488b4c623875b81fb46b545; 8f840e47f190cbe61a96945c13e9551048d42cef up to, but not including, 1502f15b9f29c41883a6139f2923523873282a83; 8f840e47f190cbe61a96945c13e9551048d42cef up to, but not including, d828b0fe6631f3ae8709ac9a10c77c5836c76a08; 8f840e47f190cbe61a96945c13e9551048d42cef up to, but not including, 633593a808980f82d251d0ca89730d8bb8b0220c; and 1 more ranges3fc0fd724d199e061432b66a8d85b7d48fe485f7, 41a2864cf719c17294f417726edd411643462ab8, 2d8fa3fdf4542a2174a72d92018f488d65d848c5, bbf59d7ae558940cfa2b36a287fd1e88d83f89f8, b7e4d9ba2ddb78801488b4c623875b81fb46b545, 1502f15b9f29c41883a6139f2923523873282a83
LinuxLinux Kernel4.7 up to, but not including, 4.9.307; 4.10 up to, but not including, 4.14.272; 4.15 up to, but not including, 4.19.235; 4.20 up to, but not including, 5.4.185; 5.5 up to, but not including, 5.10.106; 5.11 up to, but not including, 5.15.29; 5.16 up to, but not including, 5.16.154.9.307, 4.14.272, 4.19.235, 5.4.185, 5.10.106, 5.15.29

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: sctp: fix kernel-infoleak for SCTP sockets syzbot reported a kernel infoleak [1] of 4 bytes. After analysis, it turned out r->idiag_expires is not initialized if inet_sctp_diag_fill() calls inet_diag_msg_common_fill() Make sure to clear idiag_timer/idiag_retrans/idiag_expires and let inet_diag_msg_sctpasoc_fill() fill them again if needed. [1] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:154 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 instrument_copy_to_user include/linux/instrumented.h:121 [inline] copyout lib/iov_iter.c:154 [inline] _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 copy_to_iter include/linux/uio.h:162 [inline] simple_copy_to_iter+0xf3/0x140 net/core/datagram.c:519 __skb_datagram_iter+0x2d5/0x11b0 net/core/datagram.c:425 skb_copy_datagram_iter+0xdc/0x270 net/core/datagram.c:533 skb_copy_datagram_msg include/linux/skbuff.h:3696 [inline] netlink_recvmsg+0x669/0x1c80 net/netlink/af_netlink.c:1977 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] __sys_recvfrom+0x795/0xa10 net/socket.c:2097 __do_sys_recvfrom net/socket.c:2115 [inline] __se_sys_recvfrom net/socket.c:2111 [inline] __x64_sys_recvfrom+0x19d/0x210 net/socket.c:2111 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3247 [inline] __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4975 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0x545/0xf90 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] netlink_dump+0x3e5/0x16c0 net/netlink/af_netlink.c:2248 __netlink_dump_start+0xcf8/0xe90 net/netlink/af_netlink.c:2373 netlink_dump_start include/linux/netlink.h:254 [inline] inet_diag_handler_cmd+0x2e7/0x400 net/ipv4/inet_diag.c:1341 sock_diag_rcv_msg+0x24a/0x620 netlink_rcv_skb+0x40c/0x7e0 net/netlink/af_netlink.c:2494 sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x1093/0x1360 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x14d9/0x1720 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] sock_write_iter+0x594/0x690 net/socket.c:1061 do_iter_readv_writev+0xa7f/0xc70 do_iter_write+0x52c/0x1500 fs/read_write.c:851 vfs_writev fs/read_write.c:924 [inline] do_writev+0x645/0xe00 fs/read_write.c:967 __do_sys_writev fs/read_write.c:1040 [inline] __se_sys_writev fs/read_write.c:1037 [inline] __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Bytes 68-71 of 2508 are uninitialized Memory access of size 2508 starts at ffff888114f9b000 Data copied to user address 00007f7fe09ff2e0 CPU: 1 PID: 3478 Comm: syz-executor306 Not tainted 5.17.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

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

The underlying weakness: Missing Release of Memory after Effective Lifetime

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

How developers prevent this class of flaw

  • Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone. For example, glibc in Linux provides protection against free of invalid pointers. When using Xcode to target OS X or iOS, enable automatic reference counting (ARC). To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Consider using the Boehm-Demers-Weiser garbage collector (bdwgc), which can help avoid leaks.

More Missing Release of Memory after Effective Lifetime vulnerabilities (CWE-401)

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 Release of Memory after Effective Lifetime vulnerabilities

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