From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) (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 930F632ED33 for ; Mon, 20 Oct 2025 16:46:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760978804; cv=none; b=HnMER9IVy+pAwMuPkrTVw98L01Yga/UsmAgdWn5s7iilktwg6eAr+24iMAYstgtBTb42/5jSNtlVEr4STysTnHe/e/4dXfhVM/DDV/vAwo8kKjCE3ovsdbkQpklOqRVPWwvu/NwmztjldjBJbUhMnHcxCLhyhZYWLBZUl6CHRPY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760978804; c=relaxed/simple; bh=Odavzxy2BexwWoqgDcsWU58hygNdpI9KxmoPErhga9k=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=n+OB+En0iTa7G0FAcwwblLSYZWuw1krYKZhY9pThvAlz1lwKte+KnmwFUHwnGUieOPuVDAsspcHirwZcVtB6VIVd91Xu6TkZQwz/u+QcWpqJ3vEI9TTYzCqiEPjvbbNi8bNTmi7iXY/XeP7IlaSQQ4E9ZBF7cdAS1WLD929Zf/w= 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=WN8OgGbm; arc=none smtp.client-ip=91.218.175.170 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="WN8OgGbm" 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=1760978788; 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=vXz+Yf4/WKVtEjAJq5FbJ83Q1qsQ3bOt3NklG6ERV94=; b=WN8OgGbm5xQc6P42AtQSVcS8lRotIJfemBonNfUMd4iXm7TXqjP55tMnczXbu4EakwR4NB vHz/+woV5HVx4sKf1gPj7BBEtB3JObQUhfifJZu1Vqd/ecrTJT6UxOa9a0cE2JzdywdUMI EbJCKXBcOMiDp45XT6wW9j1fk3HPfbg= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, memxor@gmail.com, linux-kernel@vger.kernel.org, kernel-patches-bot@fb.com, Leon Hwang Subject: [PATCH bpf v2 0/4] bpf: Fix possible memleak when updating hash and local storage maps Date: Tue, 21 Oct 2025 00:46:04 +0800 Message-ID: <20251020164608.20536-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT In the discussion thread "[PATCH bpf-next v9 0/7] bpf: Introduce BPF_F_CPU and BPF_F_ALL_CPUS flags for percpu maps"[1], it was pointed out that missing calls to bpf_obj_free_fields() could lead to memory leaks. A selftest was added to confirm that this is indeed a real issue - the memory referenced by BPF_KPTR_{REF,PERCPU} fields is not freed when bpf_obj_free_fields() is missing after copy_map_value[,_long](). Further inspection of copy_map_value[,_long]() call sites revealed two locations affected by this issue: 1. pcpu_copy_value() 2. htab_map_update_elem() when used with BPF_F_LOCK This series fixes the leaks by properly calling bpf_obj_free_fields() (or check_and_free_fields()) after copy_map_value[,_long]() and adds selftests to verify the fix. Changes: v1 -> v2: * Add test to verify no memleak when updating cgroup local storage maps. * Address review from AI bot: * Fast path without bucket lock (around line 610) in 'bpf_local_storage.c'. v1: https://lore.kernel.org/bpf/20251016145801.47552-1-leon.hwang@linux.dev/ Links: [1] https://lore.kernel.org/bpf/20250930153942.41781-1-leon.hwang@linux.dev/ Leon Hwang (4): bpf: Fix possible memleak in [lru_,]percpu_hash map update bpf: Fix possible memleak when updating hash maps with BPF_F_LOCK bpf: Fix possible memleak when updating local storage maps with BPF_F_LOCK selftests/bpf: Add tests to verify no memleak when updating hash and cgrp storage maps kernel/bpf/bpf_local_storage.c | 1 + kernel/bpf/hashtab.c | 4 + .../bpf/prog_tests/refcounted_kptr.c | 167 +++++++++++++++++- .../selftests/bpf/progs/refcounted_kptr.c | 160 +++++++++++++++++ 4 files changed, 331 insertions(+), 1 deletion(-) -- 2.51.0