From patchwork Mon Oct 14 11:34:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Su Hui X-Patchwork-Id: 13834824 Received: from mail.nfschina.com (unknown [42.101.60.213]) by smtp.subspace.kernel.org (Postfix) with SMTP id 983B8199FC9; Mon, 14 Oct 2024 11:34:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=42.101.60.213 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728905674; cv=none; b=Rc6mbuwBRQPXFs/Krmkuu8ugwQSDbkoUHfrVhHh9bUjYESLRXM+JFvhGn4F+yzedxT8WS2YIMJNqDkjeRiqCL9UQg8EiQWYg+UuxsHkzXq80JW6NIgeql0Vb4tbxyVrC324XG37ZBmVZFBa0ItPP0BTrgDi9rrkAvz7kfAyJHXI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728905674; c=relaxed/simple; bh=ThPRdg45K9j18k7kJQg4d7R/8No7KsuZx8IRz4txea8=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version:Content-Type; b=Ro85D6dSzmd+G0MaGTXmIDYucWlaiCkLbZf3JA152vsDScrfhaXjKx20b0+lUbFryakiZmCeyyeOJFSnaq5A7zXy0vqdvNJNwBvItN1f7vrcRj1Do4Z85frIwkX1FUpB5cn2BZLDWggt/BTEnjUnuEoN11loUiq/bX7BP200pkg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=nfschina.com; spf=pass smtp.mailfrom=nfschina.com; arc=none smtp.client-ip=42.101.60.213 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=nfschina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nfschina.com Received: from localhost.localdomain (unknown [180.167.10.98]) by mail.nfschina.com (MailData Gateway V2.8.8) with ESMTPSA id B34606019980E; Mon, 14 Oct 2024 19:34:23 +0800 (CST) X-MD-Sfrom: suhui@nfschina.com X-MD-SrcIP: 180.167.10.98 From: Su Hui To: sfrench@samba.org, pc@manguebit.com, ronniesahlberg@gmail.com, sprasad@microsoft.com, stfrench@microsoft.com, tom@talpey.com, bharathsm@microsoft.com, nathan@kernel.org, ndesaulniers@google.com, morbo@google.com, justinstitt@google.com Cc: Su Hui , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, kernel-janitors@vger.kernel.org Subject: [PATCH] smb: client: fix possible double free in smb2_set_ea() Date: Mon, 14 Oct 2024 19:34:17 +0800 Message-Id: <20241014113416.2280986-1-suhui@nfschina.com> X-Mailer: git-send-email 2.30.2 Precedence: bulk X-Mailing-List: linux-cifs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Clang static checker(scan-build) warning： fs/smb/client/smb2ops.c:1304:2: Attempt to free released memory. 1304 | kfree(ea); | ^~~~~~~~~ There is a double free in such case: 'ea is initialized to NULL' -> 'first successful memory allocation for ea' -> 'something failed, goto sea_exit' -> 'first memory release for ea' -> 'goto replay_again' -> 'second goto sea_exit before allocate memory for ea' -> 'second memory release for ea resulted in double free'. Assign NULL value to 'ea' after 'kfree(ea)', it can fix this double free problem. Fixes: 4f1fffa23769 ("cifs: commands that are retried should have replay flag set") Signed-off-by: Su Hui --- fs/smb/client/smb2ops.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 6b385fce3f2a..5b42b352b703 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -1302,6 +1302,7 @@ smb2_set_ea(const unsigned int xid, struct cifs_tcon *tcon, sea_exit: kfree(ea); + ea = NULL; SMB2_open_free(&rqst[0]); SMB2_set_info_free(&rqst[1]); SMB2_close_free(&rqst[2]);