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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Dear Linux Kernel Maintainers, I hope this message finds you well. I am writing to report a potential vulnerability I encountered during testing of the Linux Kernel version v6.12. Git Commit: adc218676eef25575469234709c2d87185ca223a (tag: v6.12) Bug Location: neigh_timer_handler+0xc17/0xfe0 net/core/neighbour.c:1148 Bug report: https://pastebin.com/06NiBtXm Entire kernel config: https://pastebin.com/MRWGr3nv Root Cause Analysis: A soft lockup occurs in the neighbor subsystem due to prolonged execution within neigh_timer_handler(), where repeated neighbor entry invalidation and associated routing operations (e.g., ipv4_link_failure() and arp_error_report()) lead to excessive CPU occupation without yielding, triggering the kernel watchdog. At present, I have not yet obtained a minimal reproducer for this issue. However, I am actively working on reproducing it, and I will promptly share any additional findings or a working reproducer as soon as it becomes available. Thank you very much for your time and attention to this matter. I truly appreciate the efforts of the Linux kernel community. Best regards, Luka