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CVE-2022-49372· NVD / CVE Program· CNA Linux

tcp: tcp_rtx_synack() can be called from process context

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: 0.29% (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 0a0f7f84148445c9f02f226928803a870139d820, 0a375c822497ed6ad6b5da0792a12a6f1af10c0b, 3db889f883e65bbd3b1401279bfc1e9ed255c481.

Low priority for now. Upgrade to Linux Linux 0a0f7f84148445c9f02f226928803a870139d820, 0a375c822497ed6ad6b5da0792a12a6f1af10c0b, 3db889f883e65bbd3b1401279bfc1e9ed255c481 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: tcp: tcp_rtx_synack() can be called from process context Laurent reported the enclosed report [1] This bug triggers with following coditions: 0) Kernel built with CONFIG_DEBUG_PREEMPT=y 1) A new passive FastOpen TCP socket is created. This FO socket waits for an ACK coming from client to be a complete ESTABLISHED one. 2) A socket operation on this socket goes through lock_sock() release_sock() dance. 3) While the socket is owned by the user in step 2), a retransmit of the SYN is received and stored in socket backlog. 4) At release_sock() time, the socket backlog is processed while in process context. 5) A SYNACK packet is cooked in response of the SYN retransmit. 6) -> tcp_rtx_synack() is called in process context. Before blamed commit, tcp_rtx_synack() was always called from BH handler, from a timer handler. Fix this by using TCP_INC_STATS() & NET_INC_STATS() which do not assume caller is in non preemptible context. [1] BUG: using __this_cpu_add() in preemptible [00000000] code: epollpep/2180 caller is tcp_rtx_synack.part.0+0x36/0xc0 CPU: 10 PID: 2180 Comm: epollpep Tainted: G OE 5.16.0-0.bpo.4-amd64 #1 Debian 5.16.12-1~bpo11+1 Hardware name: Supermicro SYS-5039MC-H8TRF/X11SCD-F, BIOS 1.7 11/23/2021 Call Trace: <TASK> dump_stack_lvl+0x48/0x5e check_preemption_disabled+0xde/0xe0 tcp_rtx_synack.part.0+0x36/0xc0 tcp_rtx_synack+0x8d/0xa0 ? kmem_cache_alloc+0x2e0/0x3e0 ? apparmor_file_alloc_security+0x3b/0x1f0 inet_rtx_syn_ack+0x16/0x30 tcp_check_req+0x367/0x610 tcp_rcv_state_process+0x91/0xf60 ? get_nohz_timer_target+0x18/0x1a0 ? lock_timer_base+0x61/0x80 ? preempt_count_add+0x68/0xa0 tcp_v4_do_rcv+0xbd/0x270 __release_sock+0x6d/0xb0 release_sock+0x2b/0x90 sock_setsockopt+0x138/0x1140 ? __sys_getsockname+0x7e/0xc0 ? aa_sk_perm+0x3e/0x1a0 __sys_setsockopt+0x198/0x1e0 __x64_sys_setsockopt+0x21/0x30 do_syscall_64+0x38/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 26, 2025
Updated
Jun 17, 2026
EPSS
0.2% · 20th percentile
CWE
—

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%

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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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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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 kernel3.7 and later · before 4.9.318
  • linux linux kernel4.10 and later · before 4.14.283
  • linux linux kernel4.15 and later · before 4.19.247
  • linux linux kernel4.20 and later · before 5.4.198
  • linux linux kernel5.5 and later · before 5.10.122
  • linux linux kernel5.11 and later · before 5.15.47
  • linux linux kernel5.16 and later · before 5.17.15
  • linux linux kernel5.18 and later · before 5.18.4

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

    • 3.7affected
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before 3db889f883e65bbd3b1401279bfc1e9ed255c481affected · git
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before c348b0f8d035fc4bdc040796889beec7218bd1b8affected · git
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before 58bd38cbc961fd799842b7be8c5222310f04b908affected · git
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before d05c2fdf8e10528bb6751bd95243e862d5402a9baffected · git
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before 0a0f7f84148445c9f02f226928803a870139d820affected · git
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before 88cd232146207ff1d41dededed5e77c0d4438113affected · git
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before bdc28a8fb43cc476e33b11519235adb816ce00e8affected · git
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before d8e1bc6029acac796293310aacef7b7336f35b6aaffected · git
    • 168a8f58059a22feb9e9a2dcc1b8053dbbbc12ef and later · before 0a375c822497ed6ad6b5da0792a12a6f1af10c0baffected · git

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.18.5-15.18.5-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • 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
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2022-49370Feb 26, 2025 · firmware: dmi-sysfs: Fix memory leak in dmi_sysfs_register_handle
    22Monitor
  • ← EarlierCVE-2022-49371Feb 26, 2025 · driver core: fix deadlock in __device_attach
    22Monitor
  • Later →CVE-2022-49373Feb 26, 2025 · watchdog: ts4800_wdt: Fix refcount leak in ts4800_wdt_probe
    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 Linux0a0f7f84148445c9f02f226928803a870139d820Vendor (CNA)
Linux Linux0a375c822497ed6ad6b5da0792a12a6f1af10c0bVendor (CNA)
Linux Linux3db889f883e65bbd3b1401279bfc1e9ed255c481Vendor (CNA)
Linux Linux58bd38cbc961fd799842b7be8c5222310f04b908Vendor (CNA)
Linux Linux88cd232146207ff1d41dededed5e77c0d4438113Vendor (CNA)
Linux Linuxbdc28a8fb43cc476e33b11519235adb816ce00e8Vendor (CNA)
Linux Linuxc348b0f8d035fc4bdc040796889beec7218bd1b8Vendor (CNA)
Linux Linuxd05c2fdf8e10528bb6751bd95243e862d5402a9bVendor (CNA)
Linux Linuxd8e1bc6029acac796293310aacef7b7336f35b6aVendor (CNA)
debian:linux5.18.5-1 · 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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)

—

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 (8 more)

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

All records