bpf: fix end-of-list detection in cgroup_storage_get_next_key()

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: fix end-of-list detection in cgroup_storage_get_next_key() list_next_entry() never returns NULL -- when the current element is the last entry it wraps to the list head via container_of(). The subsequent NULL check is therefore dead code and get_next_key() never returns -ENOENT for the last element, instead reading storage->key from a bogus pointer that aliases internal map fields and copying the result to userspace. Replace it with list_entry_is_head() so the function correctly returns -ENOENT when there are no more entries.

Timeline

1. May 27, 2026, 9:24 AM UTCCVE published
2. Oct 15, 2026, 1:19 AM UTCRecord last updated

Affected versions

• Linux Linux

  From de9cbbaadba5adf88a19e46df61f7054000838f6 · fixed in 0f3d9dd5e1fd52b39e25328307c6a694e994ffe3; From de9cbbaadba5adf88a19e46df61f7054000838f6 · fixed in 26d3339e465e54107bd85884341d1609c5300d6a; From de9cbbaadba5adf88a19e46df61f7054000838f6 · fixed in 2c88b2d96e1d4d0c7c4589a4593d4cdee6d332d6; From de9cbbaadba5adf88a19e46df61f7054000838f6 · fixed in b4b5a20bed82130da2f2818f04d52378952fbd0b; From de9cbbaadba5adf88a19e46df61f7054000838f6 · fixed in 85a2f30e40f7468db732f55659bc6318874f49af; From de9cbbaadba5adf88a19e46df61f7054000838f6 · fixed in 32ce55d424395904986f5066f8755f6cb9993377; From de9cbbaadba5adf88a19e46df61f7054000838f6 · fixed in fc39753b7f92e09177777e9c648afe5aa3abb81f; From de9cbbaadba5adf88a19e46df61f7054000838f6 · fixed in 5828b9e5b272ecff7cf5d345128d3de7324117f7

• Linux Linux

  4.19

• KernelLinux

  From 4.19.0 · fixed in 5.10.258; From 5.11.0 · fixed in 5.15.209; From 5.16.0 · fixed in 6.1.175; From 6.2.0 · fixed in 6.6.141; From 6.7.0 · fixed in 6.12.91; From 6.13.0 · fixed in 6.18.33; From 6.19.0 · fixed in 7.0.10

References 8