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NVD / CVE Program· CNA Linux

CVE-2024-36938: bpf, skmsg: Fix NULL pointer dereference in sk_psock_skb_ingress_enqueue

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.24% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 39dc9e1442385d6e9be0b6491ee488dddd55ae27, 5965bc7535fb87510b724e5465ccc1a1cf00916d, 6648e613226e18897231ab5e42ffc29e63fa3365; azl3 kernel 6.6.29.1-5 on Azure Linux 3.0 6.6.35.1-4; azl3 kernel 6.6.35.1-4 on Azure Linux 3.0 6.6.35.1-4.

Low priority for now. Upgrade to Linux Linux 39dc9e1442385d6e9be0b6491ee488dddd55ae27, 5965bc7535fb87510b724e5465ccc1a1cf00916d, 6648e613226e18897231ab5e42ffc29e63fa3365; azl3 kernel 6.6.29.1-5 on Azure Linux 3.0 6.6.35.1-4; azl3 kernel 6.6.35.1-4 on Azure Linux 3.0 6.6.35.1-4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: bpf, skmsg: Fix NULL pointer dereference in sk_psock_skb_ingress_enqueue Fix NULL pointer data-races in sk_psock_skb_ingress_enqueue() which syzbot reported [1]. [1] BUG: KCSAN: data-race in sk_psock_drop / sk_psock_skb_ingress_enqueue write to 0xffff88814b3278b8 of 8 bytes by task 10724 on cpu 1: sk_psock_stop_verdict net/core/skmsg.c:1257 [inline] sk_psock_drop+0x13e/0x1f0 net/core/skmsg.c:843 sk_psock_put include/linux/skmsg.h:459 [inline] sock_map_close+0x1a7/0x260 net/core/sock_map.c:1648 unix_release+0x4b/0x80 net/unix/af_unix.c:1048 __sock_release net/socket.c:659 [inline] sock_close+0x68/0x150 net/socket.c:1421 __fput+0x2c1/0x660 fs/file_table.c:422 __fput_sync+0x44/0x60 fs/file_table.c:507 __do_sys_close fs/open.c:1556 [inline] __se_sys_close+0x101/0x1b0 fs/open.c:1541 __x64_sys_close+0x1f/0x30 fs/open.c:1541 do_syscall_64+0xd3/0x1d0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 read to 0xffff88814b3278b8 of 8 bytes by task 10713 on cpu 0: sk_psock_data_ready include/linux/skmsg.h:464 [inline] sk_psock_skb_ingress_enqueue+0x32d/0x390 net/core/skmsg.c:555 sk_psock_skb_ingress_self+0x185/0x1e0 net/core/skmsg.c:606 sk_psock_verdict_apply net/core/skmsg.c:1008 [inline] sk_psock_verdict_recv+0x3e4/0x4a0 net/core/skmsg.c:1202 unix_read_skb net/unix/af_unix.c:2546 [inline] unix_stream_read_skb+0x9e/0xf0 net/unix/af_unix.c:2682 sk_psock_verdict_data_ready+0x77/0x220 net/core/skmsg.c:1223 unix_stream_sendmsg+0x527/0x860 net/unix/af_unix.c:2339 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x140/0x180 net/socket.c:745 ____sys_sendmsg+0x312/0x410 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x1e9/0x280 net/socket.c:2667 __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x46/0x50 net/socket.c:2674 do_syscall_64+0xd3/0x1d0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 value changed: 0xffffffff83d7feb0 -> 0x0000000000000000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 10713 Comm: syz-executor.4 Tainted: G W 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Prior to this, commit 4cd12c6065df ("bpf, sockmap: Fix NULL pointer dereference in sk_psock_verdict_data_ready()") fixed one NULL pointer similarly due to no protection of saved_data_ready. Here is another different caller causing the same issue because of the same reason. So we should protect it with sk_callback_lock read lock because the writer side in the sk_psock_drop() uses "write_lock_bh(&sk->sk_callback_lock);". To avoid errors that could happen in future, I move those two pairs of lock into the sk_psock_data_ready(), which is suggested by John Fastabend.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 30, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 15th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.20 and later · before 5.15.159
  • linux linux kernel5.16 and later · before 6.1.91
  • linux linux kernel6.2 and later · before 6.6.31
  • linux linux kernel6.7 and later · before 6.8.10

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.20affected
    • 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before c0809c128dad4c3413818384eb06a341633db973affected · git
    • 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 5965bc7535fb87510b724e5465ccc1a1cf00916daffected · git
    • 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 39dc9e1442385d6e9be0b6491ee488dddd55ae27affected · git
    • 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before b397a0ab8582c533ec0c6b732392f141fc364f87affected · git
    • 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 772d5729b5ff0df0d37b32db600ce635b2172f80affected · git
    • 604326b41a6fb9b4a78b6179335decee0365cd8c and later · before 6648e613226e18897231ab5e42ffc29e63fa3365affected · git
    • before 4.20not affected · semver
    • 5.10.223 and later · up to and including 5.10.*not affected · semver
    • 5.15.159 and later · up to and including 5.15.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:11linuxbefore 5.10.223-15.10.223-1
Debian:12linuxbefore 6.1.94-16.1.94-1
Debian:13linuxbefore 6.8.11-16.8.11-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2024-36936May 30, 2024 · efi/unaccepted: touch soft lockup during memory accept
    22Monitor
  • ← EarlierCVE-2024-36937May 30, 2024 · xdp: use flags field to disambiguate broadcast redirect
    22Monitor
  • Later →CVE-2024-36941May 30, 2024 · wifi: nl80211: don't free NULL coalescing rule
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux39dc9e1442385d6e9be0b6491ee488dddd55ae27Vendor (CNA)
Linux Linux5965bc7535fb87510b724e5465ccc1a1cf00916dVendor (CNA)
Linux Linux6648e613226e18897231ab5e42ffc29e63fa3365Vendor (CNA)
Linux Linux772d5729b5ff0df0d37b32db600ce635b2172f80Vendor (CNA)
Linux Linuxb397a0ab8582c533ec0c6b732392f141fc364f87Vendor (CNA)
Linux Linuxc0809c128dad4c3413818384eb06a341633db973Vendor (CNA)
azl3 kernel 6.6.29.1-5 on Azure Linux 3.06.6.35.1-4 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.35.1-4 on Azure Linux 3.06.6.35.1-4 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.158.2-1 on CBL Mariner 2.05.15.158.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.94-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records