From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-223.mta0.migadu.com [91.218.175.223]) (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 5B33D3B0AC7 for ; Sun, 18 Oct 2026 16:28:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.223 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792340937; cv=none; b=qPITsi/zLeutItrsI2DduXyP7QS8u5KSBujnnZwydbrdBQExbRleqYkoi9QPLKHhJGYvrxF1/YKY2kkIN3QRHmKv+yLhMZCpNADAwSM6FBsFsLG9loSStScg+ZXdPi2FIdgkakIt9uYxJmFgBKSLQuJFB+yg6b0TMkn+EIu9N6E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792340937; c=relaxed/simple; bh=L42fux9FkX7PdFA0Fbfsqg8O/3baLdxzaRMtvglaHYw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=h7s//eN+vfKs5LlNCnLmqOGpTsY7GN6Xn94VKv+kVRGviDMVkx4EnGdi5J4LeAEBE62qTU0wyXxZppP7OjNhngyT3oCRPmoQiN4URQqdCWPG2UZbPVrT+2x0z3Vz3Gh58Xzi5tGiOjXDCKxk++2rsPQRumM/HjA5x+/r2ip44jg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=sjCLl7hz; arc=none smtp.client-ip=91.218.175.223 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="sjCLl7hz" X-Envelope-To: linux-trace-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=L42fux9FkX7PdFA0Fbfsqg8O/3baLdxzaRMtvglaHYw=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792340933; v=1; x=1792945733; b=sjCLl7hzK8/AzsPIANOdRQPqWK1kpU/4pi7aC8CdEmi6UYMc3x3yzhDK4+VyuWAqnSLVb4P/ NQxO9EzQCJWJMx/u9+j9OlD3eNydBNjf20/pj3YQZ4tzpE7ySCelYOFN/rC3Sc30lSNJ5grJCfg pjblbGYVYHDSPNRSWk985q4s= X-Envelope-To: linux-trace-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 67c9c5eea7512f8c; Sun, 18 Oct 2026 16:28:53 +0000 X-Mizu-Trace-ID: 67c9c5eea7512f8c X-Migadu-Flow: FLOW_OUT Message-ID: <6dc8b3e5-b4fe-45f6-9ed6-137c00e7d7db@linux.dev> Date: Mon, 19 Oct 2026 00:28:48 +0800 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next 1/6] bpf: Add syscall common attrs support for link_create To: sashiko-reviews@lists.linux.dev, bpf@vger.kernel.org Cc: linux-trace-kernel@vger.kernel.org References: <20261017142649.51047-1-leon.hwang@linux.dev> <20261017142649.51047-2-leon.hwang@linux.dev> Content-Language: en-US From: Leon Hwang In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2026/10/17 22:39, sashiko-bot@kernel.org wrote: [...] >> out: >> - if (ret < 0) >> + /* preserve original error even if log finalization is successful */ >> + err = bpf_log_attr_finalize(&attr_log, log); >> + if (err) >> + ret = err; >> + >> + kfree(log); >> + >> + if (ret < 0 && prog) >> bpf_prog_put(prog); >> return ret; >> } > > [Severity: Critical] > Can this underflow the refcount on prog and leak the newly installed link > file descriptor if bpf_log_attr_finalize() fails after link attachment > succeeds? Correct. To avoid such prog leak, I'd like to report the log_true_size twice. ret = bpf_log_attr_report_size(&attr_log, 0); if (ret) goto out; switch (prog->type) { /* ... */ } out: if (ret) { int err = bpf_log_attr_finalize(&attr_log, log); ret = err ? err : ret; } if (ret < 0 && prog) bpf_prog_put(prog); kfree(log); return ret; Thanks, Leon > [...]