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NVD / CVE Program· CNA Linux

CVE-2025-37786: net: dsa: free routing table on probe failure

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.19% (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 51df5513cca6349d0bea01bab95cd96cf869976e, 5c8066fbdb9653c6e9a224bdcd8f9c91a484f0de, 6c20894d21600ca1e8549086dfbb986e277bf8a6; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1; azl3 kernel 6.6.92.2-1 on Azure Linux 3.0 6.6.92.2-1.

Low priority for now. Upgrade to Linux Linux 51df5513cca6349d0bea01bab95cd96cf869976e, 5c8066fbdb9653c6e9a224bdcd8f9c91a484f0de, 6c20894d21600ca1e8549086dfbb986e277bf8a6; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1; azl3 kernel 6.6.92.2-1 on Azure Linux 3.0 6.6.92.2-1 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: net: dsa: free routing table on probe failure If complete = true in dsa_tree_setup(), it means that we are the last switch of the tree which is successfully probing, and we should be setting up all switches from our probe path. After "complete" becomes true, dsa_tree_setup_cpu_ports() or any subsequent function may fail. If that happens, the entire tree setup is in limbo: the first N-1 switches have successfully finished probing (doing nothing but having allocated persistent memory in the tree's dst->ports, and maybe dst->rtable), and switch N failed to probe, ending the tree setup process before anything is tangible from the user's PoV. If switch N fails to probe, its memory (ports) will be freed and removed from dst->ports. However, the dst->rtable elements pointing to its ports, as created by dsa_link_touch(), will remain there, and will lead to use-after-free if dereferenced. If dsa_tree_setup_switches() returns -EPROBE_DEFER, which is entirely possible because that is where ds->ops->setup() is, we get a kasan report like this: ================================================================== BUG: KASAN: slab-use-after-free in mv88e6xxx_setup_upstream_port+0x240/0x568 Read of size 8 at addr ffff000004f56020 by task kworker/u8:3/42 Call trace: __asan_report_load8_noabort+0x20/0x30 mv88e6xxx_setup_upstream_port+0x240/0x568 mv88e6xxx_setup+0xebc/0x1eb0 dsa_register_switch+0x1af4/0x2ae0 mv88e6xxx_register_switch+0x1b8/0x2a8 mv88e6xxx_probe+0xc4c/0xf60 mdio_probe+0x78/0xb8 really_probe+0x2b8/0x5a8 __driver_probe_device+0x164/0x298 driver_probe_device+0x78/0x258 __device_attach_driver+0x274/0x350 Allocated by task 42: __kasan_kmalloc+0x84/0xa0 __kmalloc_cache_noprof+0x298/0x490 dsa_switch_touch_ports+0x174/0x3d8 dsa_register_switch+0x800/0x2ae0 mv88e6xxx_register_switch+0x1b8/0x2a8 mv88e6xxx_probe+0xc4c/0xf60 mdio_probe+0x78/0xb8 really_probe+0x2b8/0x5a8 __driver_probe_device+0x164/0x298 driver_probe_device+0x78/0x258 __device_attach_driver+0x274/0x350 Freed by task 42: __kasan_slab_free+0x48/0x68 kfree+0x138/0x418 dsa_register_switch+0x2694/0x2ae0 mv88e6xxx_register_switch+0x1b8/0x2a8 mv88e6xxx_probe+0xc4c/0xf60 mdio_probe+0x78/0xb8 really_probe+0x2b8/0x5a8 __driver_probe_device+0x164/0x298 driver_probe_device+0x78/0x258 __device_attach_driver+0x274/0x350 The simplest way to fix the bug is to delete the routing table in its entirety. dsa_tree_setup_routing_table() has no problem in regenerating it even if we deleted links between ports other than those of switch N, because dsa_link_touch() first checks whether the port pair already exists in dst->rtable, allocating if not. The deletion of the routing table in its entirety already exists in dsa_tree_teardown(), so refactor that into a function that can also be called from the tree setup error path. In my analysis of the commit to blame, it is the one which added dsa_link elements to dst->rtable. Prior to that, each switch had its own ds->rtable which is freed when the switch fails to probe. But the tree is potentially persistent memory.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
May 1, 2025
Updated
Jun 17, 2026
EPSS
0.1% · 8th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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 exploit code appears or is weaponized
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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 kernel5.5 and later · before 6.6.88
  • linux linux kernel6.7 and later · before 6.12.25
  • linux linux kernel6.13 and later · before 6.14.4
  • linux linux kernel6.15

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

    • 5.5affected
    • c5f51765a1f60b701840544faf3ca63204b8dc3c and later · before 51df5513cca6349d0bea01bab95cd96cf869976eaffected · git
    • c5f51765a1f60b701840544faf3ca63204b8dc3c and later · before 6c20894d21600ca1e8549086dfbb986e277bf8a6affected · git
    • c5f51765a1f60b701840544faf3ca63204b8dc3c and later · before fb12b460ec46c9efad98de6d9ba349691db51dc7affected · git
    • c5f51765a1f60b701840544faf3ca63204b8dc3c and later · before 5c8066fbdb9653c6e9a224bdcd8f9c91a484f0deaffected · git
    • c5f51765a1f60b701840544faf3ca63204b8dc3c and later · before a038f5f15af455dfe35bc68549e02b950978700aaffected · git
    • c5f51765a1f60b701840544faf3ca63204b8dc3c and later · before 8bf108d7161ffc6880ad13a0cc109de3cf631727affected · git
    • before 5.5not affected · semver
    • 5.15.201 and later · up to and including 5.15.*not affected · semver
    • 6.1.164 and later · up to and including 6.1.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:11linux-6.1before 6.1.164-1~deb11u16.1.164-1~deb11u1
Debian:12linuxbefore 6.1.164-16.1.164-1
Debian:13linuxbefore 6.12.25-16.12.25-1
SUSE:Linux Micro 6.1kernel-defaultbefore 6.4.0-31.16.4.0-31.1
SUSE:Linux Micro 6.1kernel-default-basebefore 6.4.0-31.1.21.96.4.0-31.1.21.9
SUSE:Linux Micro 6.1kernel-kvmsmallbefore 6.4.0-31.16.4.0-31.1
SUSE:Linux Micro 6.1kernel-rtbefore 6.4.0-34.16.4.0-34.1
SUSE:Linux Micro 6.1kernel-sourcebefore 6.4.0-31.16.4.0-31.1
SUSE:Linux Micro 6.1kernel-source-rtbefore 6.4.0-34.16.4.0-34.1

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-2025-37783May 1, 2025 · drm/msm/dpu: Fix error pointers in dpu_plane_virtual_atomic_check
    22Monitor
  • ← EarlierCVE-2025-37784May 1, 2025 · net: ti: icss-iep: Fix possible NULL pointer dereference for perout request
    22Monitor
  • Later →CVE-2025-37787May 1, 2025 · net: dsa: mv88e6xxx: avoid unregistering devlink regions which were never registered
    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 Linux51df5513cca6349d0bea01bab95cd96cf869976eVendor (CNA)
Linux Linux5c8066fbdb9653c6e9a224bdcd8f9c91a484f0deVendor (CNA)
Linux Linux6c20894d21600ca1e8549086dfbb986e277bf8a6Vendor (CNA)
Linux Linux8bf108d7161ffc6880ad13a0cc109de3cf631727Vendor (CNA)
Linux Linuxa038f5f15af455dfe35bc68549e02b950978700aVendor (CNA)
Linux Linuxfb12b460ec46c9efad98de6d9ba349691db51dc7Vendor (CNA)
azl3 kernel 6.6.85.1-4 on Azure Linux 3.06.6.92.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.92.2-1 on Azure Linux 3.06.6.92.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0Release NotesMicrosoft (MSRC)
debian:linux6.1.164-1 · Debian:12Package registry (OSV)
debian:linux-6.16.1.164-1~deb11u1 · Debian:11Package registry (OSV)
suse:kernel-default6.4.0-31.1 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-default-base6.4.0-31.1.21.9 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-kvmsmall6.4.0-31.1 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-rt6.4.0-34.1 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-source6.4.0-31.1 · SUSE:Linux Micro 6.1Package registry (OSV)
suse:kernel-source-rt6.4.0-34.1 · SUSE:Linux Micro 6.1Package 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
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

c
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);

Fixed

c
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);

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