virtio-devices: Check MSI-X vector bounds before table access - #8138
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| if vector as usize >= self.msix_table_size { | ||
| warn!("MSI-X vector {vector} out of range, no notifier"); |
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What does "no notifier" mean here? is it "not notifying" ?
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As the notifier() method returns the EventFd associated with a given MSI-X vector, when the vector is out of range there's none exists. Rephrased to "notifier unavailable" to make that clearer.
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A malicious or buggy guest can write an out-of-bounds value to queue_msix_vector or msix_config. When the device later triggers an interrupt, it indexes into table_entries with the unchecked vector, causing a panic. Validate the vector against the MSI-X table size in both trigger() and notifier() paths, logging a warning and returning early when the vector exceeds the table bounds. Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that firing an interrupt with a queue vector beyond the MSI-X table size returns Ok without panicking. Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that triggering an interrupt when the vector is set to VIRTQ_MSI_NO_VECTOR short-circuits and returns Ok. Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that requesting a notifier with an out-of-bounds MSI-X vector returns None instead of panicking. Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that a valid in bounds vector with MSI-X enabled successfully triggers the interrupt source group. Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that firing a config change interrupt with msix_config vector beyond the table size returns Ok without panicking. Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
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A malicious or buggy guest can write an out-of-bounds value to queue_msix_vector or msix_config. When the device later triggers an interrupt, it indexes into table_entries with the unchecked vector, causing a panic.
Validate the vector against the MSI-X table size in both trigger() and notifier() paths, logging a warning and returning early when the vector exceeds the table bounds.
Added also initial unit tests module and tests covering the behavior.