In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Prevent lock inversion deadlock in map delete elem
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 map_delete_elem
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);
local_irq_disable();
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 map_delete_elem 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
Configurations
Configuration 1 (hide)
|
Configuration 2 (hide)
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History
No history.
Information
Published : 2024-05-19 09:15
Updated : 2024-12-30 17:12
NVD link : CVE-2024-35895
Mitre link : CVE-2024-35895
CVE.ORG link : CVE-2024-35895
JSON object : View
Products Affected
linux
- linux_kernel
debian
- debian_linux
CWE
CWE-667
Improper Locking