CyberSecBulletin
CVE-2022-50164NVD status: Modified

Linux: Double Free

Published Updated By the CyberSecBulletin desk

CVE-2022-50164 is a high-severity double free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 5cca5f714fe6cedd2df9d8451ad8df21e6464f62, 38d71acc15a2e72806b516380af0adb3830d4639, 4a40af2b0b9517fca7ae2a030c9c0a16836303c0 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 0.34% 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 5cca5f714fe6cedd2df9d8451ad8df21e6464f62 or 38d71acc15a2e72806b516380af0adb3830d4639 or 4a40af2b0b9517fca7ae2a030c9c0a16836303c0 or ff068c25bf90d26f0aee1751553f18076b797e8d, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.4.211 or 5.10.137 or 5.15.61 or 5.18.18, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxcfbc6c4c5b91c7725ef14465b98ac347d31f2334 up to, but not including, 5cca5f714fe6cedd2df9d8451ad8df21e6464f62; cfbc6c4c5b91c7725ef14465b98ac347d31f2334 up to, but not including, 38d71acc15a2e72806b516380af0adb3830d4639; cfbc6c4c5b91c7725ef14465b98ac347d31f2334 up to, but not including, 4a40af2b0b9517fca7ae2a030c9c0a16836303c0; cfbc6c4c5b91c7725ef14465b98ac347d31f2334 up to, but not including, ff068c25bf90d26f0aee1751553f18076b797e8d; cfbc6c4c5b91c7725ef14465b98ac347d31f2334 up to, but not including, 182d3c1385f44ba7c508bf5b1292a7fe96ad4e9e; cfbc6c4c5b91c7725ef14465b98ac347d31f2334 up to, but not including, 14a3aacf517a9de725dd3219dbbcf741e31763c4; 5.15cca5f714fe6cedd2df9d8451ad8df21e6464f62, 38d71acc15a2e72806b516380af0adb3830d4639, 4a40af2b0b9517fca7ae2a030c9c0a16836303c0, ff068c25bf90d26f0aee1751553f18076b797e8d, 182d3c1385f44ba7c508bf5b1292a7fe96ad4e9e, 14a3aacf517a9de725dd3219dbbcf741e31763c4
LinuxLinux Kernel5.1 up to, but not including, 5.4.211; 5.5 up to, but not including, 5.10.137; 5.11 up to, but not including, 5.15.61; 5.16 up to, but not including, 5.18.18; 5.19 up to, but not including, 5.19.25.4.211, 5.10.137, 5.15.61, 5.18.18, 5.19.2

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
HighData or code can be modified at will.
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:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.8HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: fix double list_add at iwl_mvm_mac_wake_tx_queue After successfull station association, if station queues are disabled for some reason, the related lists are not emptied. So if some new element is added to the list in iwl_mvm_mac_wake_tx_queue, it can match with the old one and produce a BUG like this: [ 46.535263] list_add corruption. prev->next should be next (ffff94c1c318a360), but was 0000000000000000. (prev=ffff94c1d02d3388). [ 46.535283] ------------[ cut here ]------------ [ 46.535284] kernel BUG at lib/list_debug.c:26! [ 46.535290] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 46.585304] CPU: 0 PID: 623 Comm: wpa_supplicant Not tainted 5.19.0-rc3+ #1 [ 46.592380] Hardware name: Dell Inc. Inspiron 660s/0478VN , BIOS A07 08/24/2012 [ 46.600336] RIP: 0010:__list_add_valid.cold+0x3d/0x3f [ 46.605475] Code: f2 4c 89 c1 48 89 fe 48 c7 c7 c8 40 67 93 e8 20 cc fd ff 0f 0b 48 89 d1 4c 89 c6 4c 89 ca 48 c7 c7 70 40 67 93 e8 09 cc fd ff <0f> 0b 48 89 fe 48 c7 c7 00 41 67 93 e8 f8 cb fd ff 0f 0b 48 89 d1 [ 46.624469] RSP: 0018:ffffb20800ab76d8 EFLAGS: 00010286 [ 46.629854] RAX: 0000000000000075 RBX: ffff94c1c318a0e0 RCX: 0000000000000000 [ 46.637105] RDX: 0000000000000201 RSI: ffffffff9365e100 RDI: 00000000ffffffff [ 46.644356] RBP: ffff94c1c5f43370 R08: 0000000000000075 R09: 3064316334396666 [ 46.651607] R10: 3364323064316334 R11: 39666666663d7665 R12: ffff94c1c5f43388 [ 46.658857] R13: ffff94c1d02d3388 R14: ffff94c1c318a360 R15: ffff94c1cf2289c0 [ 46.666108] FS: 00007f65634ff7c0(0000) GS:ffff94c1da200000(0000) knlGS:0000000000000000 [ 46.674331] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 46.680170] CR2: 00007f7dfe984460 CR3: 000000010e894003 CR4: 00000000000606f0 [ 46.687422] Call Trace: [ 46.689906] <TASK> [ 46.691950] iwl_mvm_mac_wake_tx_queue+0xec/0x15c [iwlmvm] [ 46.697601] ieee80211_queue_skb+0x4b3/0x720 [mac80211] [ 46.702973] ? sta_info_get+0x46/0x60 [mac80211] [ 46.707703] ieee80211_tx+0xad/0x110 [mac80211] [ 46.712355] __ieee80211_tx_skb_tid_band+0x71/0x90 [mac80211] ... In order to avoid this problem, we must also remove the related lists when station queues are disabled.

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

The underlying weakness: Double Free

The product calls free() twice on the same memory address.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
  • Use a static analysis tool to find double free instances.

More Double Free vulnerabilities (CWE-415)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Double Free vulnerabilities

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