From nobody Sun Feb 8 07:07:20 2026 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 0D7E71E0489 for ; Thu, 1 May 2025 07:00:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746082825; cv=none; b=KhdPEQqfGF+GJ4MWxgp3f9x+0Q2fSd211h5NB87WqQKbpld6Ae5w6t3kmG8gc/cfjrfAGEjveEfkDzWkuMo/mJQUuKPvL9jjIQBJWXUc8LqR81r2y2SnWRxqF9deHXwP5QchXLi7WkCasJGg4LR/6AqiLVB/yhUJFetjDbqn090= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746082825; c=relaxed/simple; bh=c8IIHBKOqP/8zRONOTaQ8sX55xLc+LG986tLPWZhOiQ=; h=Date:Mime-Version:Message-ID:Subject:From:To:Content-Type; b=HFRcXQqcNFdT4UQvsSPFdalJKThf/stbaJKp+OTv0Ry7sk3z/ndyhGRMp546f+wIB6e+hetV5kn++E8QcDEQKUnh6HCSxtqx52IgFYTpv9pMBXwehkbm9b24VvQlpGRi0Lz6ZsyMNu3ueRLOxk0Mrl+Nkv4Sqw4ExQWu+VdtZzs= 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=nBXWG/Rf; arc=none smtp.client-ip=209.85.216.74 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="nBXWG/Rf" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-30a0a8ddcc4so822310a91.3 for ; Thu, 01 May 2025 00:00:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1746082819; x=1746687619; darn=vger.kernel.org; h=to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=O4YRrIcRlvenOuksykoyHqCdG2wzhEYXKqU9yvMfzTc=; b=nBXWG/Rfgz1ItKBJ8V8iVRtat2gp+1NU3kklQuOgXhxE+Cg6hRi7+/KpotVGL/Buv6 lUEqyOi74XFtLVRMs47REoSEDFJG2PA9+8+M9kabm8tg5EZ8jpA1HReNncBLb1usSjAr b+8yto7+Btg2YLDkpAWLnxO1dr3WV5PAE4DHAcL1NPRkeqX8+xQa69MfjGGqBYglTvrR O7q1lRLmUTeNIydJUpsAPtgihezul8oc7XHCK+0tCXQ8o6i9qlcUDYeBMUyK50vMRL+y +Vuq5CE41TH+ofGVBsVcs8RYe1KbMqdJQ7iiaJhusvOFYxeAZiT9ifEOeWOHKsh9Mokt VeFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746082819; x=1746687619; h=to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=O4YRrIcRlvenOuksykoyHqCdG2wzhEYXKqU9yvMfzTc=; b=Nf/wskqZ6sVCA+6Qcw3y8JC2V3fEPS+a69ET7M9dTB6U/OQJY0+6z7vWGsYg5Lw4N9 yqIeWTgvEQo7er7GdRMp+n2Sp/xxgp9Rr23GGXMBHacHTIX7OoGkQCpOv2KVKyhUPGq5 jqUgAAIFdFzUSxxYhw7T2/ldw79R+XDO7pHML3F9vgDCaBXgw7RD2q6vZ+kZgYobidWr PCTpqsocnIp5T52Pgm9SOuIhukUKUPDrar9dkFQRUko5io8JJfMB3WUy0U9JUrWf6NBQ cntc2c1bEuwFPy6t364YyDJ3xJNpk4QcHbnES1ObFJJcp76ITjt6RvKVNJXOJ9MjWtcR Gp8A== X-Forwarded-Encrypted: i=1; AJvYcCUHcysNbvn7MALXDRd3fyC4ZidNFWPS9TLN61UscPzoj1aQVa6TduIJnMHv66w69BHCvpy75EBVX0iKlrA=@vger.kernel.org X-Gm-Message-State: AOJu0YyzZC7Pkx5WqBFf47x2kF2O+4RY3LXASWxHlHL0bcz207wi3G5i tSOevWQUGOGO7hAGJGjdY22S41sGdOkSH2MWg/2xZUTlPmO+c/laAHvTHupvufqpsSG3OESMITB k25fpQQ== X-Google-Smtp-Source: AGHT+IFpl0+qcuf8ZtvMi3OotBvFMEe8ZOS4gDGfUKf8XAHd4j6NjjQqvkCBYrVSm/FN192i8J9X711d5Aw1 X-Received: from pjbsv3.prod.google.com ([2002:a17:90b:5383:b0:308:6626:81c4]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:274b:b0:2fe:a545:4c84 with SMTP id 98e67ed59e1d1-30a41eb5a8cmr2109230a91.34.1746082819308; Thu, 01 May 2025 00:00:19 -0700 (PDT) Date: Thu, 1 May 2025 00:00:03 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.49.0.967.g6a0df3ecc3-goog Message-ID: <20250501070003.22251-1-irogers@google.com> Subject: [PATCH v1] perf symbol-minimal: Fix double free in filename__read_build_id 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 , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Running the "perf script task-analyzer tests" with address sanitizer showed a double free: ``` FAIL: "test_csv_extended_times" Error message: "Failed to find required str= ing:'Out-Out;'." =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D19190=3D=3DERROR: AddressSanitizer: attempting double-free on 0x50b00= 0017b10 in thread T0: #0 0x55da9601c78a in free (perf+0x26078a) (BuildId: e7ef50e08970f017a96= fde6101c5e2491acc674a) #1 0x55da96640c63 in filename__read_build_id tools/perf/util/symbol-min= imal.c:221:2 0x50b000017b10 is located 0 bytes inside of 112-byte region [0x50b000017b10= ,0x50b000017b80) freed by thread T0 here: #0 0x55da9601ce40 in realloc (perf+0x260e40) (BuildId: e7ef50e08970f017= a96fde6101c5e2491acc674a) #1 0x55da96640ad6 in filename__read_build_id tools/perf/util/symbol-min= imal.c:204:10 previously allocated by thread T0 here: #0 0x55da9601ca23 in malloc (perf+0x260a23) (BuildId: e7ef50e08970f017a= 96fde6101c5e2491acc674a) #1 0x55da966407e7 in filename__read_build_id tools/perf/util/symbol-min= imal.c:181:9 SUMMARY: AddressSanitizer: double-free (perf+0x26078a) (BuildId: e7ef50e089= 70f017a96fde6101c5e2491acc674a) in free =3D=3D19190=3D=3DABORTING FAIL: "invocation of perf script report task-analyzer --csv-summary csvsumm= ary --summary-extended command failed" Error message: "" FAIL: "test_csvsummary_extended" Error message: "Failed to find required st= ring:'Out-Out;'." Acked-by: Namhyung Kim ---- end(-1) ---- 132: perf script task-analyzer tests : FAIL= ED! ``` The buf_size if always set to phdr->p_filesz, but that may be 0 causing a free and realloc to return NULL. This is treated in filename__read_build_id like a failure and the buffer is freed again. To avoid this problem only grow buf, meaning the buf_size will never be 0. This also reduces the number of memory (re)allocations. Fixes: b691f64360ec ("perf symbols: Implement poor man's ELF parser") Signed-off-by: Ian Rogers --- tools/perf/util/symbol-minimal.c | 34 +++++++++++++++++--------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-mini= mal.c index c6f369b5d893..d8da3da01fe6 100644 --- a/tools/perf/util/symbol-minimal.c +++ b/tools/perf/util/symbol-minimal.c @@ -147,18 +147,19 @@ int filename__read_build_id(const char *filename, str= uct build_id *bid) if (phdr->p_type !=3D PT_NOTE) continue; =20 - buf_size =3D phdr->p_filesz; offset =3D phdr->p_offset; - tmp =3D realloc(buf, buf_size); - if (tmp =3D=3D NULL) - goto out_free; - - buf =3D tmp; + if (phdr->p_filesz > buf_size) { + buf_size =3D phdr->p_filesz; + tmp =3D realloc(buf, buf_size); + if (tmp =3D=3D NULL) + goto out_free; + buf =3D tmp; + } fseek(fp, offset, SEEK_SET); - if (fread(buf, buf_size, 1, fp) !=3D 1) + if (fread(buf, phdr->p_filesz, 1, fp) !=3D 1) goto out_free; =20 - ret =3D read_build_id(buf, buf_size, bid, need_swap); + ret =3D read_build_id(buf, phdr->p_filesz, bid, need_swap); if (ret =3D=3D 0) { ret =3D bid->size; break; @@ -199,18 +200,19 @@ int filename__read_build_id(const char *filename, str= uct build_id *bid) if (phdr->p_type !=3D PT_NOTE) continue; =20 - buf_size =3D phdr->p_filesz; offset =3D phdr->p_offset; - tmp =3D realloc(buf, buf_size); - if (tmp =3D=3D NULL) - goto out_free; - - buf =3D tmp; + if (phdr->p_filesz > buf_size) { + buf_size =3D phdr->p_filesz; + tmp =3D realloc(buf, buf_size); + if (tmp =3D=3D NULL) + goto out_free; + buf =3D tmp; + } fseek(fp, offset, SEEK_SET); - if (fread(buf, buf_size, 1, fp) !=3D 1) + if (fread(buf, phdr->p_filesz, 1, fp) !=3D 1) goto out_free; =20 - ret =3D read_build_id(buf, buf_size, bid, need_swap); + ret =3D read_build_id(buf, phdr->p_filesz, bid, need_swap); if (ret =3D=3D 0) { ret =3D bid->size; break; --=20 2.49.0.967.g6a0df3ecc3-goog