CVE-2024-35895

syzkaller started using corpuses where a BPF tracing program deletes elements from a sockmap/sockhash map. Because BPF tracing programs can be invoked from any interrupt context, locks taken during a mapdeleteelem operation must be hardirq-safe. Otherwise a deadlock due to lock inversion is possible, as reported by lockdep:

   CPU0                    CPU1
   ----                    ----

lock(&htab->buckets[i].lock); localirqdisable(); lock(&host->lock); lock(&htab->buckets[i].lock); <Interrupt> lock(&host->lock);

Locks in sockmap are hardirq-unsafe by design. We expects elements to be deleted from sockmap/sockhash only in task (normal) context with interrupts enabled, or in softirq context.

Detect when mapdeleteelem operation is invoked from a context which is not hardirq-unsafe, that is interrupts are disabled, and bail out with an error.

Note that map updates are not affected by this issue. BPF verifier does not allow updating sockmap/sockhash from a BPF tracing program today.

References

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

5.10.216-1

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

Ecosystem specific

{
    "urgency": "not yet assigned"
}

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

6.1.85-1

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

Ecosystem specific

{
    "urgency": "not yet assigned"
}

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

6.8.9-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}