DEBIAN-CVE-2025-68801

In the Linux kernel, the following vulnerability has been resolved: mlxsw: spectrumrouter: Fix neighbour use-after-free We sometimes observe use-after-free when dereferencing a neighbour [1]. The problem seems to be that the driver stores a pointer to the neighbour, but without holding a reference on it. A reference is only taken when the neighbour is used by a nexthop. Fix by simplifying the reference counting scheme. Always take a reference when storing a neighbour pointer in a neighbour entry. Avoid taking a referencing when the neighbour is used by a nexthop as the neighbour entry associated with the nexthop already holds a reference. Tested by running the test that uncovered the problem over 300 times. Without this patch the problem was reproduced after a handful of iterations. [1] BUG: KASAN: slab-use-after-free in mlxswspneighentryupdate+0x2d4/0x310 Read of size 8 at addr ffff88817f8e3420 by task ip/3929 CPU: 3 UID: 0 PID: 3929 Comm: ip Not tainted 6.18.0-rc4-virtme-g36b21a067510 #3 PREEMPT(full) Hardware name: Nvidia SN5600/VMOD0013, BIOS 5.13 05/31/2023 Call Trace: <TASK> dumpstacklvl+0x6f/0xa0 printaddressdescription.constprop.0+0x6e/0x300 printreport+0xfc/0x1fb kasanreport+0xe4/0x110 mlxswspneighentryupdate+0x2d4/0x310 mlxswsprouterrifgonesync+0x35f/0x510 mlxswsprifdestroy+0x1ea/0x730 mlxswspinetaddrportvlanevent+0xa1/0x1b0 __mlxswspinetaddrlagevent+0xcc/0x130 __mlxswspinetaddrevent+0xf5/0x3c0 mlxswsprouternetdeviceevent+0x1015/0x1580 notifiercallchain+0xcc/0x150 callnetdevicenotifiersinfo+0x7e/0x100 __netdevupperdevunlink+0x10b/0x210 netdevupperdevunlink+0x79/0xa0 vrfdelslave+0x18/0x50 dosetmaster+0x146/0x7d0 dosetlink.isra.0+0x9a0/0x2880 rtnlnewlink+0x637/0xb20 rtnetlinkrcvmsg+0x6fe/0xb90 netlinkrcvskb+0x123/0x380 netlinkunicast+0x4a3/0x770 netlinksendmsg+0x75b/0xc90 __sock_sendmsg+0xbe/0x160 ____sys_sendmsg+0x5b2/0x7d0 ___sys_sendmsg+0xfd/0x180 __syssendmsg+0x124/0x1c0 dosyscall64+0xbb/0xfd0 entrySYSCALL64afterhwframe+0x4b/0x53 [...] Allocated by task 109: kasansavestack+0x30/0x50 kasansave_track+0x14/0x30 __kasan_kmalloc+0x7b/0x90 __kmallocnoprof+0x2c1/0x790 neighalloc+0x6af/0x8f0 ___neighcreate+0x63/0xe90 mlxswspnexthopneighinit+0x430/0x7e0 mlxswsp_nexthoptypeinit+0x212/0x960 mlxswspnexthop6groupinfoinit.constprop.0+0x81f/0x1280 mlxswspnexthop6groupget+0x392/0x6a0 mlxswspfib6entrycreate+0x46a/0xfd0 mlxswsprouterfib6replace+0x1ed/0x5f0 mlxswsprouterfib6eventwork+0x10a/0x2a0 processonework+0xd57/0x1390 workerthread+0x4d6/0xd40 kthread+0x355/0x5b0 retfromfork+0x1d4/0x270 retfromforkasm+0x11/0x20 Freed by task 154: kasansavestack+0x30/0x50 kasansavetrack+0x14/0x30 __kasansavefree_info+0x3b/0x60 _kasanslabfree+0x43/0x70 kmemcachefreebulk.part.0+0x1eb/0x5e0 kvfreercubulk+0x1f2/0x260 kfreercuwork+0x130/0x1b0 processonework+0xd57/0x1390 workerthread+0x4d6/0xd40 kthread+0x355/0x5b0 retfromfork+0x1d4/0x270 retfromforkasm+0x11/0x20 Last potentially related work creation: kasansavestack+0x30/0x50 kasanrecordauxstack+0x8c/0xa0 kvfreecallrcu+0x93/0x5b0 mlxswsprouterneigheventwork+0x67d/0x860 processonework+0xd57/0x1390 workerthread+0x4d6/0xd40 kthread+0x355/0x5b0 retfromfork+0x1d4/0x270 retfromforkasm+0x11/0x20

References

https://security-tracker.debian.org/tracker/CVE-2025-68801

Affected packages

Debian:11 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

5.10.249-1

Affected versions

5.*

5.10.46-4

5.10.46-5

5.10.70-1~bpo10+1

5.10.70-1

5.10.84-1

5.10.92-1~bpo10+1

5.10.92-1

5.10.92-2

5.10.103-1~bpo10+1

5.10.103-1

5.10.106-1

5.10.113-1

5.10.120-1~bpo10+1

5.10.120-1

5.10.127-1

5.10.127-2~bpo10+1

5.10.127-2

5.10.136-1

5.10.140-1

5.10.148-1

5.10.149-1

5.10.149-2

5.10.158-1

5.10.158-2

5.10.162-1

5.10.178-1

5.10.178-2

5.10.178-3

5.10.179-1

5.10.179-2

5.10.179-3

5.10.179-4

5.10.179-5

5.10.191-1

5.10.197-1

5.10.205-1

5.10.205-2

5.10.209-1

5.10.209-2

5.10.216-1

5.10.218-1

5.10.221-1

5.10.223-1

5.10.226-1

5.10.234-1

5.10.237-1

5.10.244-1

5.10.247-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-68801.json"

Debian:12 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.1.162-1

Affected versions

6.*

6.1.27-1

6.1.37-1

6.1.38-1

6.1.38-2~bpo11+1

6.1.38-2

6.1.38-3

6.1.38-4~bpo11+1

6.1.38-4

6.1.52-1

6.1.55-1~bpo11+1

6.1.55-1

6.1.64-1

6.1.66-1

6.1.67-1

6.1.69-1~bpo11+1

6.1.69-1

6.1.76-1~bpo11+1

6.1.76-1

6.1.82-1

6.1.85-1

6.1.90-1~bpo11+1

6.1.90-1

6.1.94-1~bpo11+1

6.1.94-1

6.1.98-1

6.1.99-1

6.1.106-1

6.1.106-2

6.1.106-3

6.1.112-1

6.1.115-1

6.1.119-1

6.1.123-1

6.1.124-1

6.1.128-1

6.1.129-1

6.1.133-1

6.1.135-1

6.1.137-1

6.1.139-1

6.1.140-1

6.1.147-1

6.1.148-1

6.1.153-1

6.1.158-1

6.1.159-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-68801.json"

Debian:13 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.12.69-1

Affected versions

6.*

6.12.38-1

6.12.41-1

6.12.43-1~bpo12+1

6.12.43-1

6.12.48-1

6.12.57-1~bpo12+1

6.12.57-1

6.12.63-1~bpo12+1

6.12.63-1

6.12.69-1~bpo12+1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-68801.json"

Debian:14 / linux

Package

Name: linux
Purl: pkg:deb/debian/linux?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.18.3-1

Affected versions

6.*

6.12.38-1

6.12.41-1

6.12.43-1~bpo12+1

6.12.43-1

6.12.48-1

6.12.57-1~bpo12+1

6.12.57-1

6.12.63-1~bpo12+1

6.12.63-1

6.12.69-1~bpo12+1

6.12.69-1

6.12.73-1~bpo12+1

6.12.73-1

6.13~rc6-1~exp1

6.13~rc7-1~exp1

6.13.2-1~exp1

6.13.3-1~exp1

6.13.4-1~exp1

6.13.5-1~exp1

6.13.6-1~exp1

6.13.7-1~exp1

6.13.8-1~exp1

6.13.9-1~exp1

6.13.10-1~exp1

6.13.11-1~exp1

6.14.3-1~exp1

6.14.5-1~exp1

6.14.6-1~exp1

6.15~rc7-1~exp1

6.15-1~exp1

6.15.1-1~exp1

6.15.2-1~exp1

6.15.3-1~exp1

6.15.4-1~exp1

6.15.5-1~exp1

6.15.6-1~exp1

6.16~rc7-1~exp1

6.16-1~exp1

6.16.1-1~exp1

6.16.3-1~bpo13+1

6.16.3-1

6.16.5-1

6.16.6-1

6.16.7-1

6.16.8-1

6.16.9-1

6.16.10-1

6.16.11-1

6.16.12-1~bpo13+1

6.16.12-1

6.16.12-2

6.17.2-1~exp1

6.17.5-1~exp1

6.17.6-1

6.17.7-1

6.17.7-2

6.17.8-1~bpo13+1

6.17.8-1

6.17.9-1

6.17.10-1

6.17.11-1

6.17.12-1

6.17.13-1~bpo13+1

6.17.13-1

6.18~rc4-1~exp1

6.18~rc4-1~exp2

6.18~rc5-1~exp1

6.18~rc6-1~exp1

6.18~rc7-1~exp1

6.18.1-1~exp1

6.18.2-1~exp1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-68801.json"

Debian:11 / linux-6.1

Package

Name: linux-6.1
Purl: pkg:deb/debian/linux-6.1?arch=source

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

6.1.162-1~deb11u1

Affected versions

6.*

6.1.106-3~deb11u1

6.1.106-3~deb11u2

6.1.106-3~deb11u3

6.1.112-1~deb11u1

6.1.119-1~deb11u1

6.1.128-1~deb11u1

6.1.129-1~deb11u1

6.1.137-1~deb11u1

6.1.140-1~deb11u1

6.1.147-1~deb11u1

6.1.148-1~deb11u1

6.1.153-1~deb11u1

6.1.158-1~deb11u1

6.1.159-1~deb11u1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2025-68801.json"