net: rose: include node references in rose_neigh refcount

Summary

In the Linux kernel, the following vulnerability has been resolved: net: rose: include node references in rose_neigh refcount Current implementation maintains two separate reference counting mechanisms: the 'count' field in struct rose_neigh tracks references from rose_node structures, while the 'use' field (now refcount_t) tracks references from rose_sock. This patch merges these two reference counting systems using 'use' field for proper reference management. Specifically, this patch adds incrementing and decrementing of rose_neigh->use when rose_neigh->count is incremented or decremented. This patch also modifies rose_rt_free(), rose_rt_device_down() and rose_clear_route() to properly release references to rose_neigh objects before freeing a rose_node through rose_remove_node(). These changes ensure rose_neigh structures are properly freed only when all references, including those from rose_node structures, are released. As a result, this resolves a slab-use-after-free issue reported by Syzbot.

Timeline

1. Sep 16, 2025, 1:00 PM UTCCVE published
2. Oct 15, 2026, 1:08 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 4cce478c3e82a5fc788d72adb2f4c4e983997639; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 9c547c8eee9d1cf6e744611d688b9f725cf9a115; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in d7563b456ed44151e1a82091d96f60166daea89b; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in 384210cceb1873a4c8218b27ba0745444436b728; From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 · fixed in da9c9c877597170b929a6121a68dcd3dd9a80f45

• Linux Linux

  2.6.12

• KernelLinux

  From 2.6.12 · fixed in 6.1.150; From 6.2.0 · fixed in 6.6.104; From 6.7.0 · fixed in 6.12.45; From 6.13.0 · fixed in 6.16.5

References 5