CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HIn the Linux kernel, the following vulnerability has been resolved: net: openvswitch: reallocate update replies for mismatched IDs ovs_flow_cmd_new() preallocates the optional reply skb before it takes ovs_mutex and before it knows which existing flow will be updated. That is normally fine because the skb is sized from the request flow identifier. That identifier also becomes the inserted flow's identifier. For updates, however, a request with a UFID may miss the UFID lookup and then fall back to the flow key lookup. That lookup can legitimately find an existing key-identified flow. UFIDs are optional and the flow key is the primary identifier. For echoed replies, ovs_flow_cmd_fill_info() writes the matched flow's identifier, not the request identifier used for the preallocation. A short request UFID can therefore leave too little room for the key identifier. The fill can then fail with -EMSGSIZE and hit the BUG_ON(error < 0) in the update path. Once the update target has been resolved, reallocate the reply skb if the matched flow needs a larger reply than the request identifier allowed. Do this before replacing the actions so the request can still fail cleanly if the rare extra allocation fails. A flaw was found in the Linux kernel's Open vSwitch component. When processing flow updates, the `ovs_flow_cmd_new()` function preallocates a reply buffer based on the request's flow identifier. If a shorter User Flow ID (UFID) is provided, but the system matches an existing flow with a longer key identifier, the subsequent attempt to write the matched flow's identifier into the preallocated buffer can exceed its size. This can lead to an error and trigger a kernel panic, resulting in a denial of service.
Multiple vulnerabilities have been discovered in the Linux kernel of Debian. These vulnerabilities allow for privilege escalation, data compromise, and denial of service. The affected Debian versions are prior to 6.12.10…