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commit d5e4d81da4d443d54b0b5c28ba6d26be297c509b
parent ba9f6f8954afa5224e3ed60332f7b92242b7ed0f
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed, 24 Oct 2018 11:47:32 +0100

Merge tag 'selinux-pr-20181022' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull SELinux updates from Paul Moore:
 "Three SELinux patches for v4.20, all fall under the bug-fix or
  behave-better category, which is good. All three have pretty good
  descriptions too, which is even better"

* tag 'selinux-pr-20181022' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: Add __GFP_NOWARN to allocation at str_read()
  selinux: refactor mls_context_to_sid() and make it stricter
  selinux: fix mounting of cgroup2 under older policies

Diffstat:
Msecurity/selinux/hooks.c | 5+++++
Msecurity/selinux/ss/mls.c | 178++++++++++++++++++++++++++++++++++---------------------------------------------
Msecurity/selinux/ss/mls.h | 2+-
Msecurity/selinux/ss/policydb.c | 2+-
Msecurity/selinux/ss/services.c | 12++++--------
5 files changed, 88 insertions(+), 111 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c @@ -1508,6 +1508,11 @@ static int selinux_genfs_get_sid(struct dentry *dentry, } rc = security_genfs_sid(&selinux_state, sb->s_type->name, path, tclass, sid); + if (rc == -ENOENT) { + /* No match in policy, mark as unlabeled. */ + *sid = SECINITSID_UNLABELED; + rc = 0; + } } free_page((unsigned long)buffer); return rc; diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c @@ -218,9 +218,7 @@ int mls_context_isvalid(struct policydb *p, struct context *c) /* * Set the MLS fields in the security context structure * `context' based on the string representation in - * the string `*scontext'. Update `*scontext' to - * point to the end of the string representation of - * the MLS fields. + * the string `scontext'. * * This function modifies the string in place, inserting * NULL characters to terminate the MLS fields. @@ -235,22 +233,21 @@ int mls_context_isvalid(struct policydb *p, struct context *c) */ int mls_context_to_sid(struct policydb *pol, char oldc, - char **scontext, + char *scontext, struct context *context, struct sidtab *s, u32 def_sid) { - - char delim; - char *scontextp, *p, *rngptr; + char *sensitivity, *cur_cat, *next_cat, *rngptr; struct level_datum *levdatum; struct cat_datum *catdatum, *rngdatum; - int l, rc = -EINVAL; + int l, rc, i; + char *rangep[2]; if (!pol->mls_enabled) { - if (def_sid != SECSID_NULL && oldc) - *scontext += strlen(*scontext) + 1; - return 0; + if ((def_sid != SECSID_NULL && oldc) || (*scontext) == '\0') + return 0; + return -EINVAL; } /* @@ -261,113 +258,94 @@ int mls_context_to_sid(struct policydb *pol, struct context *defcon; if (def_sid == SECSID_NULL) - goto out; + return -EINVAL; defcon = sidtab_search(s, def_sid); if (!defcon) - goto out; + return -EINVAL; - rc = mls_context_cpy(context, defcon); - goto out; + return mls_context_cpy(context, defcon); } - /* Extract low sensitivity. */ - scontextp = p = *scontext; - while (*p && *p != ':' && *p != '-') - p++; - - delim = *p; - if (delim != '\0') - *p++ = '\0'; + /* + * If we're dealing with a range, figure out where the two parts + * of the range begin. + */ + rangep[0] = scontext; + rangep[1] = strchr(scontext, '-'); + if (rangep[1]) { + rangep[1][0] = '\0'; + rangep[1]++; + } + /* For each part of the range: */ for (l = 0; l < 2; l++) { - levdatum = hashtab_search(pol->p_levels.table, scontextp); - if (!levdatum) { - rc = -EINVAL; - goto out; - } + /* Split sensitivity and category set. */ + sensitivity = rangep[l]; + if (sensitivity == NULL) + break; + next_cat = strchr(sensitivity, ':'); + if (next_cat) + *(next_cat++) = '\0'; + /* Parse sensitivity. */ + levdatum = hashtab_search(pol->p_levels.table, sensitivity); + if (!levdatum) + return -EINVAL; context->range.level[l].sens = levdatum->level->sens; - if (delim == ':') { - /* Extract category set. */ - while (1) { - scontextp = p; - while (*p && *p != ',' && *p != '-') - p++; - delim = *p; - if (delim != '\0') - *p++ = '\0'; - - /* Separate into range if exists */ - rngptr = strchr(scontextp, '.'); - if (rngptr != NULL) { - /* Remove '.' */ - *rngptr++ = '\0'; - } + /* Extract category set. */ + while (next_cat != NULL) { + cur_cat = next_cat; + next_cat = strchr(next_cat, ','); + if (next_cat != NULL) + *(next_cat++) = '\0'; + + /* Separate into range if exists */ + rngptr = strchr(cur_cat, '.'); + if (rngptr != NULL) { + /* Remove '.' */ + *rngptr++ = '\0'; + } - catdatum = hashtab_search(pol->p_cats.table, - scontextp); - if (!catdatum) { - rc = -EINVAL; - goto out; - } + catdatum = hashtab_search(pol->p_cats.table, cur_cat); + if (!catdatum) + return -EINVAL; - rc = ebitmap_set_bit(&context->range.level[l].cat, - catdatum->value - 1, 1); - if (rc) - goto out; - - /* If range, set all categories in range */ - if (rngptr) { - int i; - - rngdatum = hashtab_search(pol->p_cats.table, rngptr); - if (!rngdatum) { - rc = -EINVAL; - goto out; - } - - if (catdatum->value >= rngdatum->value) { - rc = -EINVAL; - goto out; - } - - for (i = catdatum->value; i < rngdatum->value; i++) { - rc = ebitmap_set_bit(&context->range.level[l].cat, i, 1); - if (rc) - goto out; - } - } + rc = ebitmap_set_bit(&context->range.level[l].cat, + catdatum->value - 1, 1); + if (rc) + return rc; + + /* If range, set all categories in range */ + if (rngptr == NULL) + continue; + + rngdatum = hashtab_search(pol->p_cats.table, rngptr); + if (!rngdatum) + return -EINVAL; + + if (catdatum->value >= rngdatum->value) + return -EINVAL; - if (delim != ',') - break; + for (i = catdatum->value; i < rngdatum->value; i++) { + rc = ebitmap_set_bit(&context->range.level[l].cat, i, 1); + if (rc) + return rc; } } - if (delim == '-') { - /* Extract high sensitivity. */ - scontextp = p; - while (*p && *p != ':') - p++; - - delim = *p; - if (delim != '\0') - *p++ = '\0'; - } else - break; } - if (l == 0) { + /* If we didn't see a '-', the range start is also the range end. */ + if (rangep[1] == NULL) { context->range.level[1].sens = context->range.level[0].sens; rc = ebitmap_cpy(&context->range.level[1].cat, &context->range.level[0].cat); if (rc) - goto out; + return rc; } - *scontext = ++p; - rc = 0; -out: - return rc; + + return 0; } /* @@ -379,21 +357,19 @@ out: int mls_from_string(struct policydb *p, char *str, struct context *context, gfp_t gfp_mask) { - char *tmpstr, *freestr; + char *tmpstr; int rc; if (!p->mls_enabled) return -EINVAL; - /* we need freestr because mls_context_to_sid will change - the value of tmpstr */ - tmpstr = freestr = kstrdup(str, gfp_mask); + tmpstr = kstrdup(str, gfp_mask); if (!tmpstr) { rc = -ENOMEM; } else { - rc = mls_context_to_sid(p, ':', &tmpstr, context, + rc = mls_context_to_sid(p, ':', tmpstr, context, NULL, SECSID_NULL); - kfree(freestr); + kfree(tmpstr); } return rc; diff --git a/security/selinux/ss/mls.h b/security/selinux/ss/mls.h @@ -34,7 +34,7 @@ int mls_level_isvalid(struct policydb *p, struct mls_level *l); int mls_context_to_sid(struct policydb *p, char oldc, - char **scontext, + char *scontext, struct context *context, struct sidtab *s, u32 def_sid); diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c @@ -1101,7 +1101,7 @@ static int str_read(char **strp, gfp_t flags, void *fp, u32 len) if ((len == 0) || (len == (u32)-1)) return -EINVAL; - str = kmalloc(len + 1, flags); + str = kmalloc(len + 1, flags | __GFP_NOWARN); if (!str) return -ENOMEM; diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c @@ -1365,7 +1365,6 @@ int security_sid_to_context_force(struct selinux_state *state, u32 sid, static int string_to_context_struct(struct policydb *pol, struct sidtab *sidtabp, char *scontext, - u32 scontext_len, struct context *ctx, u32 def_sid) { @@ -1426,15 +1425,12 @@ static int string_to_context_struct(struct policydb *pol, ctx->type = typdatum->value; - rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid); + rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); if (rc) goto out; - rc = -EINVAL; - if ((p - scontext) < scontext_len) - goto out; - /* Check the validity of the new context. */ + rc = -EINVAL; if (!policydb_context_isvalid(pol, ctx)) goto out; rc = 0; @@ -1489,7 +1485,7 @@ static int security_context_to_sid_core(struct selinux_state *state, policydb = &state->ss->policydb; sidtab = &state->ss->sidtab; rc = string_to_context_struct(policydb, sidtab, scontext2, - scontext_len, &context, def_sid); + &context, def_sid); if (rc == -EINVAL && force) { context.str = str; context.len = strlen(str) + 1; @@ -1958,7 +1954,7 @@ static int convert_context(u32 key, goto out; rc = string_to_context_struct(args->newp, NULL, s, - c->len, &ctx, SECSID_NULL); + &ctx, SECSID_NULL); kfree(s); if (!rc) { pr_info("SELinux: Context %s became valid (mapped).\n",