From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5D3D046F4BE; Wed, 5 Aug 2026 13:31:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785936701; cv=none; b=udgUxJe/7N39vAt1O7iABxN7gX0/bnKNs1ZpVqjAGEg0XuxicQ3dkoZkfBsP0H8VBquYOxciBHLd0L7vO35vAw9IWmuBfU2iF/WY7WEiL/3mwkqjIMwN/GK+9m/UK0N6kR/pK0UfMYdlOXgqc8pObdkduffVBh+aC2jUZ+X6J9U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785936701; c=relaxed/simple; bh=ikFrrWyhMBfQZqRUpaRPSY0QmwmGXvUmdIyzmUukMGk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mBw+/cqkAf2C+//CXD2lrUKEPvNe44g90WKm0+NlWIsxGey+7i7rtph3fWIqtJnL9eJSn0DPf6q7hYc47yc4XkElQPT8I1JcKLAEc7ciTRX6+a/A4FXDLJEgX5kIuFrXjH56F6Jdb/UdpIhbTuPTc1ZAAjX7/4Qutk1jxYz2Tqg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UXkMWRBW; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UXkMWRBW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6515A1F000E9; Wed, 5 Aug 2026 13:31:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785936700; bh=SVk7zPpKJa5wyALqfhsZ+WOrOVCyDvZ0JgLmgyEfUfM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UXkMWRBW9E9QlAidu9FmIrYhq3S3qvgkw6qOs9MHAPmlDzLYvlx8JR/Xd4qmKjpt1 bzdZkRxVn4UtnXRVsw/Bm7jtMv9isIeEkKvY99otYAft4LM93F5gyZ1dIMH/SpNpPy tqehzcsBG+x+jGpTwtFUl6nA7k5jE6jMdT0aitXvfgVrN7ULa90ViWMV32SVi3bZsA KaUTNSCS36fCm9K/vT3qdNIAihgbAolJ6T178X0wHYBwaMPVTpmEbXObJPj2WlkHsW BoHTcLlq2BC+MR+X7FNlU+svtzbgGBHxxUuS4j3cv60mrj0jDxMwzyRWBnOW0cJxS2 hJIs1pcxooQHw== From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Ingo Molnar , Thomas Gleixner , James Clark , Jiri Olsa , Ian Rogers , Adrian Hunter , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , sashiko-bot , Stephane Eranian Subject: [PATCH 05/12] perf jitdump: Check snprintf return before computing header size Date: Wed, 5 Aug 2026 10:30:04 -0300 Message-ID: <20260805133013.235016-6-acme@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260805133013.235016-1-acme@kernel.org> References: <20260805133013.235016-1-acme@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Arnaldo Carvalho de Melo snprintf() returns the would-have-been length on truncation. When the jitted filename exceeds PATH_MAX, the unclamped 'size' value inflates sizeof(event->mmap2.filename) - size into a massive underflow, causing the header.size computation to write an oversized header. The subsequent write to 'id = event + header.size - idr_size' then corrupts the heap. Clamp size to PATH_MAX - 1 after snprintf in both jit_repipe_code_load() and jit_repipe_code_move(). Fixes: 9b07e27f88b9 ("perf inject: Add jitdump mmap injection support") Reported-by: sashiko-bot Cc: Stephane Eranian Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/jitdump.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c index 078d3304d2b7ebce..fd11e07bf00b7978 100644 --- a/tools/perf/util/jitdump.c +++ b/tools/perf/util/jitdump.c @@ -493,6 +493,9 @@ static int jit_repipe_code_load(struct jit_buf_desc *jd, union jr_entry *jr) jd->dir, nspid, count); + /* snprintf returns would-be length on truncation, clamp to buffer */ + if (size >= PATH_MAX) + size = PATH_MAX - 1; size++; /* for \0 */ @@ -623,6 +626,9 @@ static int jit_repipe_code_move(struct jit_buf_desc *jd, union jr_entry *jr) jd->dir, nspid, jr->move.code_index); + /* snprintf returns would-be length on truncation, clamp to buffer */ + if (size >= PATH_MAX) + size = PATH_MAX - 1; size++; /* for \0 */ -- 2.55.0