From nobody Sat Feb 7 21:14:59 2026 Received: from out-174.mta1.migadu.com (out-174.mta1.migadu.com [95.215.58.174]) (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 1F3FF253B58; Sun, 26 Oct 2025 15:40:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.174 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761493259; cv=none; b=NQwrCrhx5M16MQJjs5LaPl0uVtTVSVh3kAdkd3KloBlpIuevkipV9W6wvLoU84kTkL8MBP9pSt9Q3h7ok99szmLuiazDUR3DM48Fw195Xe9c7sIZzjy0N+OeINgkO0dlVxS4hbACDC2k7uIPmY2In+k74/QM0yIo+ffll/7Itnk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761493259; c=relaxed/simple; bh=X7SifmAEQtPtGTwptFSvQQj76o4yROrHVpi4rvR1QjQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h5cehDZoiHLWxv9ZRRIPkzgsf/FoFX+HWcKLRSAT7nXef/6ZEQ5AUAKF7GdUw44zD0d+lfu9J5WizdU5FJIOT0siORSxAnnh+Ks8SXND5ZtHEftti23ZO2gMCLrqa+yskHNlGySQmNKRMtJvEZ/0RbJ4mZQrhUA3/0GvhLOwNp0= 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=Fx8yniAq; arc=none smtp.client-ip=95.215.58.174 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="Fx8yniAq" 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=1761493256; 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: in-reply-to:in-reply-to:references:references; bh=8AAgrBQP2Y1ONLw22Ac4cfKW6J+sJUDTFnmuPayNPe4=; b=Fx8yniAqIBRNggOhKdexNiDLm5Ri8VYEqPP7gmcl263G3X8A2OJ6OdKQFsH0FPTL6PBIlV hnGWGeFqF6WbU38if0GeGCNZxj3U6aLgLYbnhkOLgTmUYuhZY/C/zDE7NyLV4I0if5qYYu MhtLdklmKAkti5SAwmgHHqv0ef+mCgc= 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 v3 3/4] bpf: Free special fields when update local storage maps Date: Sun, 26 Oct 2025 23:39:59 +0800 Message-ID: <20251026154000.34151-4-leon.hwang@linux.dev> In-Reply-To: <20251026154000.34151-1-leon.hwang@linux.dev> References: <20251026154000.34151-1-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: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" When updating local storage maps with BPF_F_LOCK on the fast path, the special fields were not freed after being replaced. This could cause memory referenced by BPF_KPTR_{REF,PERCPU} fields to be held until the map gets freed. Similarly, on the other path, the old sdata's special fields were never freed regardless of whether BPF_F_LOCK was used, causing the same issue. Fix this by calling 'bpf_obj_free_fields()' after 'copy_map_value_locked()' to properly release the old fields. Fixes: 9db44fdd8105 ("bpf: Support kptrs in local storage maps") Signed-off-by: Leon Hwang --- kernel/bpf/bpf_local_storage.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index b931fbceb54da..8e3aea4e07c50 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -609,6 +609,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_= storage_map *smap, if (old_sdata && selem_linked_to_storage_lockless(SELEM(old_sdata))) { copy_map_value_locked(&smap->map, old_sdata->data, value, false); + bpf_obj_free_fields(smap->map.record, old_sdata->data); return old_sdata; } } @@ -641,6 +642,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_= storage_map *smap, if (old_sdata && (map_flags & BPF_F_LOCK)) { copy_map_value_locked(&smap->map, old_sdata->data, value, false); + bpf_obj_free_fields(smap->map.record, old_sdata->data); selem =3D SELEM(old_sdata); goto unlock; } @@ -654,6 +656,7 @@ bpf_local_storage_update(void *owner, struct bpf_local_= storage_map *smap, =20 /* Third, remove old selem, SELEM(old_sdata) */ if (old_sdata) { + bpf_obj_free_fields(smap->map.record, old_sdata->data); bpf_selem_unlink_map(SELEM(old_sdata)); bpf_selem_unlink_storage_nolock(local_storage, SELEM(old_sdata), true, &old_selem_free_list); --=20 2.51.0