From nobody Fri Oct 3 10:15:36 2025 Received: from mail-pf1-f202.google.com (mail-pf1-f202.google.com [209.85.210.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0783A341651 for ; Tue, 2 Sep 2025 18:17:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756837077; cv=none; b=okVJ2zLBV9RU9q4AlM8RXOm8qa6pwl+FbQJ5Rtzx2pGUkRLEHVAl4vAhng/HXsJhF8gniAyTDGOpAtVfpznojG7x7JdprOts0bpk2JY57kqWsENXAK420aE6AxnGOtJYTOs/o3gyYHVtHB4xNYLWosZ4DLtnUnjC9wiYwP3ECes= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756837077; c=relaxed/simple; bh=Y417faWxUdjMpY13VqIziiGZ5qRUWZrN43DhiAwSrlU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=lszEJSo1+r1gcdebMt7j3cjVGlRXYPIc+CdugoCE5iz/Ukt9N8R48kcHrYo6ZAusiQWNKmqG7KO/rBEuo6wbfua2JSLjlXMbKWdXCMrPTWIy/QRKYIV/j5RUwKt6dWpGdmB7uZgjhy4lUGkaMRaZRv4feriyA2X2zczgCxLuzYU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=xEmAy7zB; arc=none smtp.client-ip=209.85.210.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="xEmAy7zB" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-77243618babso3184709b3a.0 for ; Tue, 02 Sep 2025 11:17:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1756837075; x=1757441875; darn=vger.kernel.org; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=X/J1GNcMtAJTXoNioUBkgQFYPG0R3g234Hk0goUCKGI=; b=xEmAy7zBWFGbt14FqEvPeekYB3LiSh/R32Rm0tJPHAIi+1DjfHpUuKuLw9RqlZlK+K K5z09Ag2isIoC85boUX/vY4nytLaCEY1DSFo76uKm5RNUDRk0sKQ2Dp1rJZBjo6SHygR CwLvH1oL3cZ1S9EZizsECaGv1tfhP6yeadz7So0z/+peWjuBUui3MlybkMP+OqiveD8e FY3i7qHB4PsBcFVV/PC/JHN4i0Cfjyu7Y0Zm+i+U2lc5PGm9F6mK/q0D7nk+SXfFBAkf vwlj5x5Agbd9LvgjBkFbZgHE6Whey00fAmKgAbOdJuJcf6F2BxIqRIu9Mr+MXQ0OWO3z bRlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756837075; x=1757441875; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=X/J1GNcMtAJTXoNioUBkgQFYPG0R3g234Hk0goUCKGI=; b=T69r6m5QA3p0jUFlRhQJst9+PqTYD5DOJtIA3EBnM83L3IhwxMfK+Tyffa9/Lp1fxs nEe6+wRV5GnFkDDpE0kOX6u9zgyUJnwPXU+v40r09aKq1+qlY1alLBSgD61DV1GuvQ4D mGC0v3Eg0Fd0vdGKhyRcCAd1lHhd3E4b16gK3XQbGvhR7G9CndbsRaS3h9nR2gPvPNs/ GFNlbROwDmCmRmnKhKli+BMxcifn/hrZU0wsRXM1TrkzxIBGZ7I2g0MpcPdQDhVOwk0t ZAeBc/8UaviVrTHRGXNzeWuYCmmLEMbswN/jLAzGf1AUg92wZGdkBYjjFwsgr1StLpFb sEQQ== X-Forwarded-Encrypted: i=1; AJvYcCXHWSbedLTz+AMSUnuap9mZp526gjUbBXIEoCBIhU6s4lRm8gZVfHgOUGQudx2PVyQUx4W+cFMy3GgTV/g=@vger.kernel.org X-Gm-Message-State: AOJu0YxD+jnTUrhMU8QBoplFoaXQlnKEd+1DyjGaes+8Tz9/grJch2sz l4cCQppsYr4Szjx6WynCkpIMd+8/lfJcWx6VaIxLB9Cxuw9bW5XKIlbmzmssdAqkjkFaVUN6QTm YlBBwznnXSg== X-Google-Smtp-Source: AGHT+IHxdObMrTQ2jlx0SwvK/uuzTbZa58P6MBTifkyUSqcIWeTIEok/hTK+8sVzhlfi1Ugp7eD1dabFwgpf X-Received: from pfbih20.prod.google.com ([2002:a05:6a00:8c14:b0:771:f406:9f46]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:b81:b0:772:301a:fbb6 with SMTP id d2e1a72fcca58-7723e342758mr14698699b3a.19.1756837075293; Tue, 02 Sep 2025 11:17:55 -0700 (PDT) Date: Tue, 2 Sep 2025 11:17:11 -0700 In-Reply-To: <20250902181713.309797-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250902181713.309797-1-irogers@google.com> X-Mailer: git-send-email 2.51.0.355.g5224444f11-goog Message-ID: <20250902181713.309797-2-irogers@google.com> Subject: [PATCH v1 1/3] perf bpf-event: Fix use-after-free in synthesis From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , Blake Jones , Zhongqiu Han , Andrii Nakryiko , Song Liu , Dave Marchevsky , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Howard Chu , song@kernel.org, Yonghong Song Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Calls to perf_env__insert_bpf_prog_info may fail as a sideband thread may already have inserted the bpf_prog_info. Such failures may yield info_linear being freed which then causes use-after-free issues with the internal bpf_prog_info info struct. Make it so that perf_env__insert_bpf_prog_info trigger early non-error paths and fix the use-after-free in perf_event__synthesize_one_bpf_prog. Add proper return error handling to perf_env__add_bpf_info (that calls perf_env__insert_bpf_prog_info) and propagate the return value in its callers. Closes: https://lore.kernel.org/lkml/CAP-5=3DfWJQcmUOP7MuCA2ihKnDAHUCOBLkQF= EkQES-1ZZTrgf8Q@mail.gmail.com/ Fixes: 03edb7020bb9 ("perf bpf: Fix two memory leakages when calling perf_e= nv__insert_bpf_prog_info()") Signed-off-by: Ian Rogers --- tools/perf/util/bpf-event.c | 39 +++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index 5b6d3e899e11..2298cd396c42 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -657,9 +657,15 @@ static int perf_event__synthesize_one_bpf_prog(struct = perf_session *session, info_node->info_linear =3D info_linear; info_node->metadata =3D NULL; if (!perf_env__insert_bpf_prog_info(env, info_node)) { - free(info_linear); + /* + * Insert failed, likely because of a duplicate event + * made by the sideband thread. Ignore synthesizing the + * metadata. + */ free(info_node); + goto out; } + /* info_linear is now owned by info_node and shouldn't be freed below. */ info_linear =3D NULL; =20 /* @@ -827,18 +833,18 @@ int perf_event__synthesize_bpf_events(struct perf_ses= sion *session, return err; } =20 -static void perf_env__add_bpf_info(struct perf_env *env, u32 id) +static int perf_env__add_bpf_info(struct perf_env *env, u32 id) { struct bpf_prog_info_node *info_node; struct perf_bpil *info_linear; struct btf *btf =3D NULL; u64 arrays; u32 btf_id; - int fd; + int fd, err =3D 0; =20 fd =3D bpf_prog_get_fd_by_id(id); if (fd < 0) - return; + return -EINVAL; =20 arrays =3D 1UL << PERF_BPIL_JITED_KSYMS; arrays |=3D 1UL << PERF_BPIL_JITED_FUNC_LENS; @@ -852,6 +858,7 @@ static void perf_env__add_bpf_info(struct perf_env *env= , u32 id) info_linear =3D get_bpf_prog_info_linear(fd, arrays); if (IS_ERR_OR_NULL(info_linear)) { pr_debug("%s: failed to get BPF program info. aborting\n", __func__); + err =3D PTR_ERR(info_linear); goto out; } =20 @@ -862,38 +869,46 @@ static void perf_env__add_bpf_info(struct perf_env *e= nv, u32 id) info_node->info_linear =3D info_linear; info_node->metadata =3D bpf_metadata_create(&info_linear->info); if (!perf_env__insert_bpf_prog_info(env, info_node)) { + pr_debug("%s: duplicate add bpf info request for id %u\n", + __func__, btf_id); free(info_linear); free(info_node); + goto out; } - } else + } else { free(info_linear); + err =3D -ENOMEM; + goto out; + } =20 if (btf_id =3D=3D 0) goto out; =20 btf =3D btf__load_from_kernel_by_id(btf_id); - if (libbpf_get_error(btf)) { - pr_debug("%s: failed to get BTF of id %u, aborting\n", - __func__, btf_id); - goto out; + if (!btf) { + err =3D -errno; + pr_debug("%s: failed to get BTF of id %u %d\n", __func__, btf_id, err); + } else { + perf_env__fetch_btf(env, btf_id, btf); } - perf_env__fetch_btf(env, btf_id, btf); =20 out: btf__free(btf); close(fd); + return err; } =20 static int bpf_event__sb_cb(union perf_event *event, void *data) { struct perf_env *env =3D data; + int ret =3D 0; =20 if (event->header.type !=3D PERF_RECORD_BPF_EVENT) return -1; =20 switch (event->bpf.type) { case PERF_BPF_EVENT_PROG_LOAD: - perf_env__add_bpf_info(env, event->bpf.id); + ret =3D perf_env__add_bpf_info(env, event->bpf.id); =20 case PERF_BPF_EVENT_PROG_UNLOAD: /* @@ -907,7 +922,7 @@ static int bpf_event__sb_cb(union perf_event *event, vo= id *data) break; } =20 - return 0; + return ret; } =20 int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) --=20 2.51.0.355.g5224444f11-goog