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From: Leon Hwang <leon.hwang@linux.dev>
To: Vincent Thiberville <vincent@harfanglab.fr>,
	"ast@kernel.org" <ast@kernel.org>,
	"daniel@iogearbox.net" <daniel@iogearbox.net>,
	Kumar Kartikeya Dwivedi <memxor@gmail.com>,
	Eduard Zingerman <eddyz87@gmail.com>
Cc: "bpf@vger.kernel.org" <bpf@vger.kernel.org>
Subject: Re: PROBLEM: BPF interpreter fallback after JIT compilation of BPF_ADDR_PERCPU leads to kernel panic
Date: Fri, 17 Jul 2026 10:12:49 +0800	[thread overview]
Message-ID: <b76ade17-44cb-4e60-97fc-41ba55258691@linux.dev> (raw)
In-Reply-To: <MR1P264MB331493FEEA2ACE6C2AEA5EB9B7C72@MR1P264MB3314.FRAP264.PROD.OUTLOOK.COM>

On 16/7/26 19:27, Vincent Thiberville wrote:
> On 1/7/26 04:49, Leon Hwang wrote:
>> By changing 'r0 = 0' to nop, I can reproduce the BUG with bpf-next code:
> [...]
>> With this diff, the internal BPF_ADDR_PERCPU insn is supported in the interpreter.
> 
> Thank you for the investigation and further details.
> 
> Is a fix planned? This bug impacts stable versions of the kernel and is fairly
> easy to trigger notably on Debian 13. With some ebpf programs, simply
> enabling `bpf_jit_harden` on Debian 13 means a guaranteed kernel panic.

The fix is on the way [1].

Once the fix gets applied, it should be backported to kernel 6.12 with
prerequisite patch [2].

[1] https://lore.kernel.org/bpf/20260715141122.15783-4-leon.hwang@linux.dev/
[2]
https://lore.kernel.org/bpf/20260708101806.18885-1-yangtiezhu@loongson.cn/

Thanks,
Leon


      reply	other threads:[~2026-07-17  2:12 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-29 14:42 PROBLEM: BPF interpreter fallback after JIT compilation of BPF_ADDR_PERCPU leads to kernel panic Vincent Thiberville
2026-06-30  1:48 ` Leon Hwang
2026-06-30 12:08   ` Vincent Thiberville
2026-07-01  2:49     ` Leon Hwang
2026-07-16 11:27       ` Vincent Thiberville
2026-07-17  2:12         ` Leon Hwang [this message]

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