Return-Path: Received: from sonic301-28.consmr.mail.gq1.yahoo.com ([98.137.64.154]:42494 "EHLO sonic301-28.consmr.mail.gq1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752839AbeFARpR (ORCPT ); Fri, 1 Jun 2018 13:45:17 -0400 Subject: [PATCH] Smack: Fix memory leak in smack_inode_getsecctx To: chandan.vn@samsung.com, "linux-security-module@vger.kernel.org" Cc: Tejun Heo , "gregkh@linuxfoundation.org" , "bfields@fieldses.org" , "jlayton@kernel.org" , "linux-kernel@vger.kernel.org" , "linux-nfs@vger.kernel.org" , CPGS , Sireesha Talluri , Chris Wright , Casey Schaufler References: <02d9878e-65bf-5de8-9658-cf0f692f358c@schaufler-ca.com> <1ced6bce-92cc-7e0c-fab4-0aaa3d03b82f@schaufler-ca.com> <1527758911-18610-1-git-send-email-chandan.vn@samsung.com> <20180531153943.GR1351649@devbig577.frc2.facebook.com> <4f00f9ae-3302-83b9-c083-d21ade380eb2@schaufler-ca.com> <20180531161107.GV1351649@devbig577.frc2.facebook.com> <20180601085609epcms5p5fefac0156a4816e9e48751211ab595ee@epcms5p5> <20180601162913epcms5p7737f5b4376d8865af1eae119aa866550@epcms5p7> <5b0b157a-0e8c-d8f5-901e-836d545a8e4c@schaufler-ca.com> From: Casey Schaufler Message-ID: Date: Fri, 1 Jun 2018 10:45:12 -0700 MIME-Version: 1.0 In-Reply-To: <5b0b157a-0e8c-d8f5-901e-836d545a8e4c@schaufler-ca.com> Content-Type: text/plain; charset=utf-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: Fix memory leak in smack_inode_getsecctx The implementation of smack_inode_getsecctx() made incorrect assumptions about how Smack presents a security context. Smack does not need to allocate memory to support security contexts, so "releasing" a Smack context is a no-op. The code made an unnecessary copy and returned that as a context, which was never freed. The revised implementation returns the context correctly. Signed-off-by: Casey Schaufler --- security/smack/smack_lsm.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 0b414836bebd..5e3beae334a8 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -1545,9 +1545,9 @@ static int smack_inode_listsecurity(struct inode *inode, char *buffer, */ static void smack_inode_getsecid(struct inode *inode, u32 *secid) { - struct inode_smack *isp = inode->i_security; + struct smack_known *skp = smk_of_inode(inode); - *secid = isp->smk_inode->smk_secid; + *secid = skp->smk_secid; } /* @@ -4538,12 +4538,10 @@ static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) { - int len = 0; - len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true); + struct smack_known *skp = smk_of_inode(inode); - if (len < 0) - return len; - *ctxlen = len; + *ctx = skp->smk_known; + *ctxlen = strlen(skp->smk_known); return 0; }