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CVE-2026-97939

ipmr: account multicast table and route memory PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: ipmr: account multicast table and route memory A netadmin in a user+net namespace can create many IPv4 and IPv6 multicast routing tables with MRT_TABLE and MRT6_TABLE. Each unseen id allocates an mr_table via the shared mr_table_alloc(), links it into the per-net list, and leaves it until netns teardown. Those objects were not charged to memcg, so the host unreclaimable slab grows with the table count. Account mr_table allocations with GFP_KERNEL_ACCOUNT and mark the IPv4/IPv6 MFC caches SLAB_ACCOUNT. This matches the established handling of IP addresses, routes and alternate interface names. Unresolved MFC entries are still allocated from softIRQ with GFP_ATOMIC and are not charged. They expire after 10 seconds and are bounded by the socket receive queue; see commit 0079ad8e8dc3 ("ipmr: remove hard code cache_resolve_queue_len limit").

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected f0ad0860d01e47a3ffd220564c5c653b3afbe962 before 21e0749e8ef272ac7e3eefe0fa488a5983f4b038; affected f0ad0860d01e47a3ffd220564c5c653b3afbe962 before ec1c6140394ee87127479bc500a3158b125bf07a; affected f0ad0860d01e47a3ffd220564c5c653b3afbe962 before 0264b3ee09b118fec8a5471b4ca288f8ab84722f; affected f0ad0860d01e47a3ffd220564c5c653b3afbe962 before d0a2e2a4ee6bfe51e398bfb6921a7d0f4c26bc1c; affected f0ad0860d01e47a3ffd220564c5c653b3afbe962 before b7ee18725f2292ab554aa96a101ae42d45f008bd
Linux / Linuxaffected 2.6.35; unaffected 0 before 2.6.35; unaffected 6.6.160 through 6.6.*; unaffected 6.12.112 through 6.12.*; unaffected 6.18.53 through 6.18.*; unaffected 7.2.7 through 7.2.*; unaffected 7.3 through *

CWE

No CWE identifiers supplied.

References