From f50a3ec961f90e38c0311411179d5dfee1412192 Mon Sep 17 00:00:00 2001 From: Kohei Kaigai Date: Fri, 1 Apr 2011 15:39:26 +0100 Subject: [PATCH] selinux: add type_transition with name extension support for selinuxfs The attached patch allows /selinux/create takes optional 4th argument to support TYPE_TRANSITION with name extension for userspace object managers. If 4th argument is not supplied, it shall perform as existing kernel. In fact, the regression test of SE-PostgreSQL works well on the patched kernel. Thanks, Signed-off-by: KaiGai Kohei [manually verify fuzz was not an issue, and it wasn't: eparis] Signed-off-by: Eric Paris --- security/selinux/include/security.h | 4 ++-- security/selinux/selinuxfs.c | 16 ++++++++++++++-- security/selinux/ss/services.c | 17 +++++++++-------- 3 files changed, 25 insertions(+), 12 deletions(-) diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index bfc5218..2cf6708 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -112,8 +112,8 @@ void security_compute_av_user(u32 ssid, u32 tsid, int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, const struct qstr *qstr, u32 *out_sid); -int security_transition_sid_user(u32 ssid, u32 tsid, - u16 tclass, u32 *out_sid); +int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, + const char *objname, u32 *out_sid); int security_member_sid(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid); diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index ea39cb7..973f5a4 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -753,11 +753,13 @@ out: static ssize_t sel_write_create(struct file *file, char *buf, size_t size) { char *scon = NULL, *tcon = NULL; + char *namebuf = NULL, *objname = NULL; u32 ssid, tsid, newsid; u16 tclass; ssize_t length; char *newcon = NULL; u32 len; + int nargs; length = task_has_security(current, SECURITY__COMPUTE_CREATE); if (length) @@ -773,9 +775,17 @@ static ssize_t sel_write_create(struct file *file, char *buf, size_t size) if (!tcon) goto out; + length = -ENOMEM; + namebuf = kzalloc(size + 1, GFP_KERNEL); + if (!namebuf) + goto out; + length = -EINVAL; - if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3) + nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf); + if (nargs < 3 || nargs > 4) goto out; + if (nargs == 4) + objname = namebuf; length = security_context_to_sid(scon, strlen(scon) + 1, &ssid); if (length) @@ -785,7 +795,8 @@ static ssize_t sel_write_create(struct file *file, char *buf, size_t size) if (length) goto out; - length = security_transition_sid_user(ssid, tsid, tclass, &newsid); + length = security_transition_sid_user(ssid, tsid, tclass, + objname, &newsid); if (length) goto out; @@ -804,6 +815,7 @@ static ssize_t sel_write_create(struct file *file, char *buf, size_t size) length = len; out: kfree(newcon); + kfree(namebuf); kfree(tcon); kfree(scon); return length; diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 03f7a47..39d7321 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1360,14 +1360,14 @@ out: static void filename_compute_type(struct policydb *p, struct context *newcontext, u32 scon, u32 tcon, u16 tclass, - const struct qstr *qstr) + const char *objname) { struct filename_trans *ft; for (ft = p->filename_trans; ft; ft = ft->next) { if (ft->stype == scon && ft->ttype == tcon && ft->tclass == tclass && - !strcmp(ft->name, qstr->name)) { + !strcmp(ft->name, objname)) { newcontext->type = ft->otype; return; } @@ -1378,7 +1378,7 @@ static int security_compute_sid(u32 ssid, u32 tsid, u16 orig_tclass, u32 specified, - const struct qstr *qstr, + const char *objname, u32 *out_sid, bool kern) { @@ -1479,9 +1479,9 @@ static int security_compute_sid(u32 ssid, } /* if we have a qstr this is a file trans check so check those rules */ - if (qstr) + if (objname) filename_compute_type(&policydb, &newcontext, scontext->type, - tcontext->type, tclass, qstr); + tcontext->type, tclass, objname); /* Check for class-specific changes. */ if (specified & AVTAB_TRANSITION) { @@ -1539,13 +1539,14 @@ int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, const struct qstr *qstr, u32 *out_sid) { return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, - qstr, out_sid, true); + qstr ? qstr->name : NULL, out_sid, true); } -int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid) +int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, + const char *objname, u32 *out_sid) { return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, - NULL, out_sid, false); + objname, out_sid, false); } /** -- 2.7.4