From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754278AbeEaJ2y (ORCPT ); Thu, 31 May 2018 05:28:54 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:23629 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754164AbeEaJ2v (ORCPT ); Thu, 31 May 2018 05:28:51 -0400 DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20180531092849epoutp010e13475450b548b0a9d822622d52a684~zsKcCDzGW0715207152epoutp01c X-AuditID: b6c32a35-ba1ff70000000fe2-0f-5b0fc051b775 From: CHANDAN VN To: gregkh@linuxfoundation.org, tj@kernel.org, bfields@fieldses.org, jlayton@kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, casey@schaufler-ca.com Cc: cpgs@samsung.com, chandan.vn@samsung.com, sireesha.t@samsung.com Subject: [PATCH 1/1] Fix memory leak in kernfs_security_xattr_set and kernfs_security_xattr_set Date: Thu, 31 May 2018 14:58:31 +0530 Message-id: <1527758911-18610-1-git-send-email-chandan.vn@samsung.com> X-Mailer: git-send-email 1.9.1 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprHKsWRmVeSWpSXmKPExsWy7bCmgW7gAf5og31nZCxeTImyuLftF5vF hC8RFi8PaVo0L17PZvFz2Sp2i8u75rBZXDhwmtVi14UCi1/LjzI6cHlsmNrE5rFpVSebx/65 a9g9+rasYvQ4un8Rm8fnTXIBbFGpNhmpiSmpRQqpecn5KZl56bZK3sHxzvGmZgaGuoaWFuZK CnmJuam2Si4+AbpumTlAZykplCXmlAKFAhKLi5X07WyK8ktLUhUy8otLbJWiDQ2N9AwNzPWM jIC0aayVkSlQSUJqxpYTGxkLJohVPHi3kLWB8Z5QFyMnh4SAicTyl3PZuhi5OIQEdjBKNMye wwjhfGeU+HloDxNM1erZj1ghErsZJSZtvc4E4XQzSZzpeMUCUsUmoClxYt40dpCEiMAaRolz a3YwgySYBVwkTv7vYQSxhQUSJe7teA1mswioSsx99h1sBa+Am8TZD5fZINbJSZw8NhlsnYRA D5vEnW8guzmAHBeJ1uXREDXCEq+Ob2GHCEtLXDpqC2HmS7zarQBRUSHxv2ErC4RtLzFj8Vao a/gk3n3tgRrIK9HRBg0JD4lXrYvASoQEYiVmrH3BNoFRYgEjwypGsdSC4tz01GLDAkO94sTc 4tK8dL3k/NxNjOC0oWW6g3HKOZ9DjAIcjEo8vBxr+KKFWBPLiitzDzFKcDArifBOKeOPFuJN SaysSi3Kjy8qzUktPsRoCvT/RGYp0eR8YErLK4k3NDUyMzOwNLc0szCwUBLnbTP/FyUkkJ5Y kpqdmlqQWgTTx8TBKdXAeDG/IpFF2DNAZnOyhafctTMGX7KcllvdMbGqeyOpx7Pz1b/1G2aV /2csOrr7zYXAYPaAWeXLnly5K7FA8e6VHYv/BhesNzezdW0odPjkaTSdu+qzVSuH0/InnrUL emxju71C4pcvWV3gl3x61oUpify/WaYfdg/aP6f8bbRlcfyzZSKbvik8VGIpzkg01GIuKk4E ADzl8tAxAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmplluLIzCtJLcpLzFFi42I5/e+xgG7AAf5og/PvlS1eTImyuLftF5vF hC8RFi8PaVo0L17PZvFz2Sp2i8u75rBZXDhwmtVi14UCi1/LjzI6cHlsmNrE5rFpVSebx/65 a9g9+rasYvQ4un8Rm8fnTXIBbFFcNimpOZllqUX6dglcGVtObGQsmCBW8eDdQtYGxntCXYyc HBICJhKrZz9i7WLk4hAS2Mko0bxhCQuE08sksWnBGXaQKjYBTYkT86axgyREBNYwSkx/uI4R JMEs4CJx8n8PmC0skChxb8drMJtFQFVi7rPvTCA2r4CbxNkPl9kg1slJnDw2mXUCI9cCRoZV jJKpBcW56bnFRgWGeanlesWJucWleel6yfm5mxiBgbPtsFbfDsb7S+IPMQpwMCrx8HKs4YsW Yk0sK67MPcQowcGsJMI7pYw/Wog3JbGyKrUoP76oNCe1+BCjNAeLkjjv7bxjkUIC6Yklqdmp qQWpRTBZJg5OqQbGkvwJHIZ/o6e8mhw6XdzGgDM+XXpZOofkB0PRBzqPu16c5RK+K6ksd+H1 AVmOZVznXlzy2xiRcrCOaUqS9PIejjWuXVeCUgOfeS8UMC2cpBup/ZD3BMfcf9pnMzzD1Zdw uy77tFkxlTWBaaetws7W1yEdz1KXHyo2dljbNXV+4Pkvjcu2LxJVYinOSDTUYi4qTgQA5E47 lRgCAAA= X-CMS-MailID: 20180531092848epcas1p24b638ccd6da00f1e039bdb64de7e1a5b X-Msg-Generator: CA CMS-TYPE: 101P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20180531092848epcas1p24b638ccd6da00f1e039bdb64de7e1a5b References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "sireesha.t" Leak is caused because smack_inode_getsecurity() is allocating memory using kstrdup(). Though the security_release_secctx() is called, it would not free the allocated memory. Calling security_release_secctx is not relevant for this scenario as inode_getsecurity() does not provide a "secctx". Similar fix has been mainlined: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?id=57e7ba04d422c3d41c8426380303ec9b7533ded9 The fix is to replace the security_release_secctx() with a kfree() Below is the KMEMLEAK dump: unreferenced object 0xffffffc025e11c80 (size 64): comm "systemd-tmpfile", pid 2452, jiffies 4294894464 (age 235587.492s) hex dump (first 32 bytes): 53 79 73 74 65 6d 3a 3a 53 68 61 72 65 64 00 00 System::Shared.. 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] __save_stack_trace+0x28/0x34 [] create_object+0x130/0x25c [] kmemleak_alloc+0x30/0x5c [] __kmalloc_track_caller+0x1cc/0x2a8 [] kstrdup+0x3c/0x6c [] smack_inode_getsecurity+0xcc/0xec [] smack_inode_getsecctx+0x24/0x44 [] security_inode_getsecctx+0x50/0x70 [] kernfs_security_xattr_set+0x74/0xe0 [] __vfs_setxattr+0x74/0x90 [] __vfs_setxattr_noperm+0x80/0x1ac [] vfs_setxattr+0x84/0xac [] setxattr+0x114/0x178 [] path_setxattr+0x74/0xb8 [] SyS_lsetxattr+0x10/0x1c [] __sys_trace_return+0x0/0x4 Signed-off-by: sireesha.t Signed-off-by: CHANDAN VN --- fs/kernfs/inode.c | 3 ++- fs/nfsd/nfs4xdr.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c index a343039..53befb8 100644 --- a/fs/kernfs/inode.c +++ b/fs/kernfs/inode.c @@ -369,7 +369,8 @@ static int kernfs_security_xattr_set(const struct xattr_handler *handler, mutex_unlock(&kernfs_mutex); if (secdata) - security_release_secctx(secdata, secdata_len); + kfree(secdata); + return error; } diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index aaa88c1..1e0dbe9 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2911,7 +2911,7 @@ static int get_parent_attributes(struct svc_export *exp, struct kstat *stat) out: #ifdef CONFIG_NFSD_V4_SECURITY_LABEL if (context) - security_release_secctx(context, contextlen); + kfree(context); #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */ kfree(acl); if (tempfh) { -- 1.9.1