From mboxrd@z Thu Jan 1 00:00:00 1970 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 38D0B31DDBD for ; Tue, 2 Sep 2025 18:18:05 +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=1756837086; cv=none; b=B8JH2g/+SCSZgwIec+ex7k3M7jGQRA/3w3bhl6D/1VQTJ+2Myqu5uV0qw2NgUM7qyp/nbQ1y3ANAQTpSZMvy0S1YvhD8ZYIN4qG4aaEy0XdmFRZOsnOqqcvEdHMV2i/Tkd6c3TuOsP4tkoCh1ugZMOgTeMpebYoiJ9KEg819GFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756837086; c=relaxed/simple; bh=Y417faWxUdjMpY13VqIziiGZ5qRUWZrN43DhiAwSrlU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=RZbB4uXZROzE43Bu43L0OpZcrw4vFjnfOG0PqmGCYsRhmtDXaIj2XhOEYfYaNrmTNnHuzUdYdLB1DSjz+tcUS1M5xeL3VQygzH4U/JYkJSqAqC8okz+vGzq1Nak+eWs/eYCiYKGEJVrexcTJf/Dl0MJ1iHwTOskEzBVjvSE/e8s= 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=u+ZjSL8n; 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="u+ZjSL8n" Received: by mail-pf1-f202.google.com with SMTP id d2e1a72fcca58-7724046c346so2918114b3a.1 for ; Tue, 02 Sep 2025 11:18:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1756837084; x=1757441884; 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=u+ZjSL8nnSHImRDGjcGQ77E1j9gkiOzsoowRUhmEGU43EyuvXbD0vjELy7LQeZiqgV 1JgPKwDv2UySx3D7k1yz5pLs5vEFTcFxqqmNB9aE8p84DCWw7U4SmGJ5uOBXwNiKcdUb ghpHNjpEjjiOWCgFdOb87cuU4I/DeOSV3gtqn3iG26mmNvWn41+oCf2qFzxeqJFmKkNV ltEWbzastEgiAeSTGPw05twbygusCHZTmdUbv2tEayJkqxNqwsZgkkjJNGl4MGevSZBQ 3WKQ+R3xRtGcY7NhytcLJYL9GGpOt+XHGVPn7LTVix9onqxB1tKwSAOSJqDD5oq2PYhe ZMaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756837084; x=1757441884; 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=SL0j9f43yAaJvTaPqxZhF/OECS8yjsE7390BNcHWveYq2ar1Er7iVYW/JbXzXU4oRR nt3qDcK2AAuVOIw7j1rNYJq66dRJn90WW1j6heyjb/KW4ax334dgRdt1Oz0f3HNL15wI +1LgJUdoysQtO2Qao8Jor2XO0a7j12cFqFDwW7xxmTNYEPFOeFnLrllEQw0phJvN2TES oAPKqNweJZ0yROGCPc8sEHLinn96WYBu4UBt/zm2G2tB6/bn9IRGoXd0HHvhCEZS+9ZF UvLyAR3DEpa3U/E1imZVa63Bxn5NgrzSnRuJzyEs2lVcTnZGoQ7kADBXPVDVGgwGK0Wz 2gtA== X-Forwarded-Encrypted: i=1; AJvYcCUPDtIgEmKwturPHd0biMs9YAoPftPgymStWq1SQ/8WrB3tLsntw3FoIlTwqWc1Iw67sjeoK/QJJWEQTo4M6GG2@vger.kernel.org X-Gm-Message-State: AOJu0YwBPcJpbcbOir8VaQaBDqrmmsyEmHiC9fdgGwZuYBPY8pZ3Qp05 fwCmg2NUB7r0X2utBfqhXc0jJRyBOLQlSm6cxjsQ/+IOQTElErLVmaoU/rlu+zwIu+lQuoKVxx7 3wYoGs5mhWg== 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-perf-users@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-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=fWJQcmUOP7MuCA2ihKnDAHUCOBLkQFEkQES-1ZZTrgf8Q@mail.gmail.com/ Fixes: 03edb7020bb9 ("perf bpf: Fix two memory leakages when calling perf_env__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 = info_linear; info_node->metadata = 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 = NULL; /* @@ -827,18 +833,18 @@ int perf_event__synthesize_bpf_events(struct perf_session *session, return err; } -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 = NULL; u64 arrays; u32 btf_id; - int fd; + int fd, err = 0; fd = bpf_prog_get_fd_by_id(id); if (fd < 0) - return; + return -EINVAL; arrays = 1UL << PERF_BPIL_JITED_KSYMS; arrays |= 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 = 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 = PTR_ERR(info_linear); goto out; } @@ -862,38 +869,46 @@ static void perf_env__add_bpf_info(struct perf_env *env, u32 id) info_node->info_linear = info_linear; info_node->metadata = 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 = -ENOMEM; + goto out; + } if (btf_id == 0) goto out; btf = 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 = -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); out: btf__free(btf); close(fd); + return err; } static int bpf_event__sb_cb(union perf_event *event, void *data) { struct perf_env *env = data; + int ret = 0; if (event->header.type != PERF_RECORD_BPF_EVENT) return -1; switch (event->bpf.type) { case PERF_BPF_EVENT_PROG_LOAD: - perf_env__add_bpf_info(env, event->bpf.id); + ret = perf_env__add_bpf_info(env, event->bpf.id); case PERF_BPF_EVENT_PROG_UNLOAD: /* @@ -907,7 +922,7 @@ static int bpf_event__sb_cb(union perf_event *event, void *data) break; } - return 0; + return ret; } int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) -- 2.51.0.355.g5224444f11-goog