CVE-2021-47060
KVM: Stop looking for coalesced MMIO zones if the bus is destroyed
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Description
In the Linux kernel, the following vulnerability has been resolved: KVM: Stop looking for coalesced MMIO zones if the bus is destroyed Abort the walk of coalesced MMIO zones if kvm_io_bus_unregister_dev() fails to allocate memory for the new instance of the bus. If it can't instantiate a new bus, unregister_dev() destroys all devices _except_ the target device. But, it doesn't tell the caller that it obliterated the bus and invoked the destructor for all devices that were on the bus. In the coalesced MMIO case, this can result in a deleted list entry dereference due to attempting to continue iterating on coalesced_zones after future entries (in the walk) have been deleted. Opportunistically add curly braces to the for-loop, which encompasses many lines but sneaks by without braces due to the guts being a single if statement.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
Patch and advisory references
- https://git.kernel.org/stable/c/168e82f640ed1891a700bdb43e37da354b2ab63c
- https://git.kernel.org/stable/c/2a20592baff59c5351c5200ec667e1a2aa22af85
- https://git.kernel.org/stable/c/50cbad42bfea8c052b7ca590bd4126cdc898713c
- https://git.kernel.org/stable/c/5d3c4c79384af06e3c8e25b7770b6247496b4417
- https://git.kernel.org/stable/c/7d1bc32d6477ff96a32695ea4be8144e4513ab2d
References (5)
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