From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C051A3C13E3 for ; Wed, 5 Aug 2026 04:05:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785902717; cv=none; b=DMO4mrkTB6E8Z7Hm244moNuqMtUmClnbQkbfDzkk4XvKHPRhrEVodmKT+sdXuCW3jcPSzzBwk3R6G5eC3XGh9Jx5abLuFXkkIjh4qTNvq5p14Nw925T2nkgadE9aqBAvATOJyuiLVeWz12VYmaNhIdSnKYMc151ir2VjEmlIj2g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785902717; c=relaxed/simple; bh=C4RSpaljxgz9ck9DLpKyKQn84ey1xXzE5fy+mwxZT30=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MQnLLg/fdPuFUGEQbsau9SmPCtb1YpV/i/yViLBihVo7khvxF+bG/x5LtmJpNMh/FLWNEbsiPOa5VGPyunTR5pWnmgEVMw/X4Z7xZaeReManXmZgx1DTSG51jHQ1vw21JgCPVCthO88nTnW+fWqacPZz6bUE0J41qdgGKwEbDw0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=iCBwrPOz; arc=none smtp.client-ip=91.218.175.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="iCBwrPOz" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1785902703; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=0tlFxTrd/+tW4EBqbHQI+10YL1gDs4/3VHY2K0901z4=; b=iCBwrPOzfiQVdDl8SZdNAEmJzMXVis/m7VsjNVxUpw16S0SOZ1QGzz6sm3U4e0VuGIhzrC 410U8/PyN1uDw91wDpaDPb3W3DdgNsfXmG2BpKQxdoYOTjWhXHS6O2rShePC8FVfsatYNs J1v8gFD/Ev/RiN50cBlcHxsPil7Gyg0= From: "Hui Zhu" To: Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , KP Singh , Matt Bobrowski , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Hui Zhu Subject: [PATCH bpf-next v2 0/3] bpf: Fix UAF in bpf_trampoline_multi_attach/detach on update failure Date: Wed, 5 Aug 2026 12:04:05 +0800 Message-ID: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Hui Zhu This series fixes several use-after-free issues in the BPF trampoline multi-attach/detach error paths, where ftrace direct-call updates can fail and leave ftrace pointing at freed memory. Patch 1 addresses two UAF scenarios in bpf_trampoline_multi_detach(): the single-point unlink failure path (old_image == cur_image) and the batch ftrace update failure path. A new pinned_prog field in struct bpf_tramp_image keeps the bpf_prog alive while ftrace may still reference its image. bpf_trampoline_multi_detach() is made to return void, since callers cannot usefully react to failures, and bpf_trampoline_put() is taught to leak the trampoline when cur_image was left behind by a rollback, so ftrace keeps a valid target. Patch 2 fixes a similar UAF in bpf_trampoline_multi_attach() rollback: when the register-path undo fails, ftrace still calls into cur_image, so the prog is pinned on cur_image instead of being rolled back. Patch 3 fixes the common __bpf_trampoline_unlink_prog() path, covering both multi (bpf_trampoline_multi_detach) and non-multi (bpf_tracing_link_release, bpf_shim_tramp_link_release) callers. Hui Zhu (3): bpf: Fix UAF in bpf_trampoline_multi_detach on update failure bpf: Fix prog UAF in bpf_trampoline_multi_attach() register-path rollback bpf: Fix prog UAF in __bpf_trampoline_unlink_prog() on update failure include/linux/bpf.h | 20 +++-- kernel/bpf/trampoline.c | 183 +++++++++++++++++++++++++++++++++++---- kernel/trace/bpf_trace.c | 2 +- 3 files changed, 183 insertions(+), 22 deletions(-) Changelog: v2: Folded v1's two detach patches into patch 1. According to the comments of Jiri Olsa, Pin the prog (pinned_prog) on cur_image so it stays alive while ftrace may still call into it. Make bpf_trampoline_multi_detach() return void. Fix the same UAF in standard (non-multi) trampolines. According to the comments of sashiko, Fix the prog UAF in bpf_trampoline_multi_attach() rollback. Leak the trampoline in bpf_trampoline_put() when cur_image is left by a rollback. -- 2.53.0