From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f72.google.com (mail-pj1-f72.google.com [209.85.216.72]) (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 7D7DF4582CF for ; Tue, 21 Jul 2026 20:58:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784667493; cv=none; b=pxQW2r4iGhCAx4f6PaFaHmtp3AxEfUnoYgf4spZJHCIXlRgcYrhaZWRsUB2s+QoTGlJnkq3sNIo0Mwv5cpz/BmX6x5Qp0CfegOHTYxTjV/676tsFT4Spqx9TGjJJGStMYWdOrj57KS9Ilt1eyw1qTldOYzh/Mlz9SKEXYuern2M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784667493; c=relaxed/simple; bh=Rhr9/VWiAOU2ysPViZ6y1/ZtZdHQlWxwu4lXWxiMujo=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=JpFn5d757OXSvEA0T4o+gEGHJ3Sfwzik1W7uOghtTcTNK48AC5I46tB9aw4m6bo7ZALTEfsqNe0hFGcsHK6Rlt3ohztD0UNqtvcrY80Jt7scTHX8huchkX3vht3av6HHpRRLWqfUPSFHJ+ddyEgVIS2cd/2CT1StQUf3ogAlS0s= 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=SaZBC2Zn; arc=none smtp.client-ip=209.85.216.72 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="SaZBC2Zn" Received: by mail-pj1-f72.google.com with SMTP id 98e67ed59e1d1-381250979d5so8962624a91.0 for ; Tue, 21 Jul 2026 13:58:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784667477; x=1785272277; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=WPc/SptN9OuaHPCuk46SdIx0RLVLfa1pOthKWdfhXgQ=; b=SaZBC2ZnnQ5quRLHCQeJ6pmmuIw2IMAbE1D9Ym9M+OWFUvYt+pdwk4aXbiLHwkwKCD h/02jhs6nxp6SuGG54yrmnuYZxhOzj7tcc/J68w+7o+xxxLR+xDTqOdvBSoe9juOOX7g wlsn8q8n+ZBAUONoKrHFUq/j50t5ThDgC0BbOM7QLblnQE3WkLXmV92XmlIYViF7m+gy mrUcSCNdwAO+N78SEJSiPq9Dk25bpbgp+tS1+rL0PMSkLsbstCBtq9Qlwa022mJfZWod pKfxcTU08tWslpivH6xunPQwEwHwabYO5iV8L20sI9jOKsMJJPRmnr2xF1ViwztzA1Hq ql0g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784667477; x=1785272277; h=content-type:cc: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:content-type; bh=WPc/SptN9OuaHPCuk46SdIx0RLVLfa1pOthKWdfhXgQ=; b=gp2swkOJaDDCtSbhXomLd3j7oMYSllCFMrg4CkL9Dhg8x7pwcteKlAiq4TFbGPkMii GPS0Cn6r2XV0Q6J2wb4q2SNVYW62sQFIbJym6zVPZHqdNxXjhAJLYftBMTRWDEKjNjQ5 J9NyVbCJ9L8XgTYWDJojXy6JCqtU5nPkxVVhYtnz54HNuvMbtM/BqyfW76hLZAXPEdXo q5Dy1pH3ej0nUGINUHKHvWFIiaWfsVXmGCGaHqfm35NBeuhgrPUhJza61IqaHPa7TPYi rYsPh+KzIX9v7o/eTWmWgSpfCXd0/L0rd50PMKwEyT/zodwPjHg6f18rnEgS3/uqL9vR 3fCw== X-Forwarded-Encrypted: i=1; AHgh+RoV0a4q2nNJ2OgY5glORu39Ll5jBN6ToQJvuOyNq4UdVKcfG0ZMoRLb9p2Tk5owDcN0ZU4PCQ6r8ChUAGU=@vger.kernel.org X-Gm-Message-State: AOJu0Yy8w4QxWUlWb25EXQZrtK+SP6kN9pMGc81kogZf3XKYalj8wOtw 6ypYzP4+1iM0tFO7BlzmjZwNmOoOgQaIVScWiim/h29OZgA3hr38SIl4jOddgfjd8fj3wf5E79w K7GqiVAG3+A== X-Received: from dlea1-n2.prod.google.com ([2002:a05:701b:4201:20b0:13b:8289:9a55]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:d886:b0:37f:9cdf:f03c with SMTP id 98e67ed59e1d1-38e4b54082emr19361084a91.31.1784667477256; Tue, 21 Jul 2026 13:57:57 -0700 (PDT) Date: Tue, 21 Jul 2026 13:57:46 -0700 In-Reply-To: <20260721205746.183206-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260721182150.94016-1-irogers@google.com> <20260721205746.183206-1-irogers@google.com> X-Mailer: git-send-email 2.55.0.229.g6434b31f56-goog Message-ID: <20260721205746.183206-5-irogers@google.com> Subject: [PATCH v5 4/4] perf synthetic-events: Fix bounds and union member access in mmap2 build_id synthesis From: Ian Rogers To: irogers@google.com, acme@kernel.org, namhyung@kernel.org Cc: adrian.hunter@intel.com, james.clark@linaro.org, jolsa@kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, ravi.bangoria@amd.com, swapnil.sapkal@amd.com Content-Type: text/plain; charset="UTF-8" Modify bounds and union member access in mmap2 build_id synthesis. Bound max_filename_len against the minimum of filename array capacity and the outer union stack layout minus sample ID trailers. This prevents both -E2BIG overruns and _FORTIFY_SOURCE array bounds aborts on strlcpy even if the enclosing union expands. Assisted-by: Antigravity:gemini-3.5-flash Signed-off-by: Ian Rogers --- tools/perf/util/synthetic-events.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c index 4043d17a6140..704760e1dd5d 100644 --- a/tools/perf/util/synthetic-events.c +++ b/tools/perf/util/synthetic-events.c @@ -2450,13 +2450,18 @@ int perf_event__synthesize_mmap2_build_id(const struct perf_tool *tool, size_t filename_len = strlen(filename); size_t ev_len; u64 sample_type = sample->evsel ? sample->evsel->core.attr.sample_type : 0; - void *array; + void *array = &ev; int ret; + size_t max_filename_len; - if (filename_len >= sizeof(ev.mmap2.filename)) - return -EINVAL; + max_filename_len = min(sizeof(ev.mmap2.filename) - 1, + sizeof(ev) - (MAX_ID_HDR_ENTRIES * sizeof(__u64)) - + offsetof(struct perf_record_mmap2, filename) - 1); - ev_len = sizeof(ev.mmap2) - sizeof(ev.mmap2.filename) + filename_len + 1; + if (filename_len > max_filename_len) + filename_len = max_filename_len; + + ev_len = offsetof(struct perf_record_mmap2, filename) + filename_len + 1; ev_len = PERF_ALIGN(ev_len, sizeof(u64)); if (ev_len + MAX_ID_HDR_ENTRIES * sizeof(__u64) > sizeof(ev)) @@ -2476,16 +2481,15 @@ int perf_event__synthesize_mmap2_build_id(const struct perf_tool *tool, ev.mmap2.build_id_size = bid->size; if (ev.mmap2.build_id_size > sizeof(ev.mmap2.build_id)) - ev.build_id.size = sizeof(ev.mmap2.build_id); + ev.mmap2.build_id_size = sizeof(ev.mmap2.build_id); memcpy(ev.mmap2.build_id, bid->data, ev.mmap2.build_id_size); ev.mmap2.prot = prot; ev.mmap2.flags = flags; - memcpy(ev.mmap2.filename, filename, min(strlen(filename), sizeof(ev.mmap.filename))); + strlcpy(ev.mmap2.filename, filename, filename_len + 1); - array = &ev; - array += ev.header.size; + array = (void *)((char *)&ev + ev.header.size); ret = perf_event__synthesize_id_sample(array, sample_type, sample); if (ret < 0) return ret; -- 2.55.0.229.g6434b31f56-goog