diff options
author | Eric Paris <eparis@redhat.com> | 2010-11-29 15:47:09 -0500 |
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committer | Eric Paris <eparis@redhat.com> | 2010-11-30 17:28:57 -0500 |
commit | 23bdecb000c806cf4ec52764499a600f7200d7a9 (patch) | |
tree | f13a523f6bec22c5e7ec58ea02a4988aefe7c8ac | |
parent | c41ab6a1b9028de33e74101cb0aae13098a56fdb (diff) | |
download | linux-stable-23bdecb000c806cf4ec52764499a600f7200d7a9.tar.gz linux-stable-23bdecb000c806cf4ec52764499a600f7200d7a9.tar.bz2 linux-stable-23bdecb000c806cf4ec52764499a600f7200d7a9.zip |
selinux: convert type_val_to_struct to flex_array
In rawhide type_val_to_struct will allocate 26848 bytes, an order 3
allocations. While this hasn't been seen to fail it isn't outside the
realm of possibiliy on systems with severe memory fragmentation. Convert
to flex_array so no allocation will ever be bigger than PAGE_SIZE.
Signed-off-by: Eric Paris <eparis@redhat.com>
-rw-r--r-- | security/selinux/ss/policydb.c | 28 | ||||
-rw-r--r-- | security/selinux/ss/policydb.h | 2 | ||||
-rw-r--r-- | security/selinux/ss/services.c | 17 |
3 files changed, 34 insertions, 13 deletions
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 6ad73e81da5c..af41fdfe1a71 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -307,7 +307,11 @@ static int type_index(void *key, void *datum, void *datap) || typdatum->bounds > p->p_types.nprim) return -EINVAL; p->p_type_val_to_name[typdatum->value - 1] = key; - p->type_val_to_struct[typdatum->value - 1] = typdatum; + /* this flex array was all preallocated, this cannot fail */ + if (flex_array_put_ptr(p->type_val_to_struct_array, + typdatum->value - 1, typdatum, + GFP_KERNEL | __GFP_ZERO)) + BUG(); } return 0; @@ -484,11 +488,17 @@ static int policydb_index_others(struct policydb *p) if (!p->user_val_to_struct) goto out; + /* Yes, I want the sizeof the pointer, not the structure */ rc = -ENOMEM; - p->type_val_to_struct = - kmalloc(p->p_types.nprim * sizeof(*(p->type_val_to_struct)), - GFP_KERNEL); - if (!p->type_val_to_struct) + p->type_val_to_struct_array = flex_array_alloc(sizeof(struct type_datum *), + p->p_types.nprim, + GFP_KERNEL | __GFP_ZERO); + if (!p->type_val_to_struct_array) + goto out; + + rc = flex_array_prealloc(p->type_val_to_struct_array, 0, + p->p_types.nprim - 1, GFP_KERNEL | __GFP_ZERO); + if (rc) goto out; rc = -ENOMEM; @@ -699,7 +709,8 @@ void policydb_destroy(struct policydb *p) kfree(p->class_val_to_struct); kfree(p->role_val_to_struct); kfree(p->user_val_to_struct); - kfree(p->type_val_to_struct); + if (p->type_val_to_struct_array) + flex_array_free(p->type_val_to_struct_array); avtab_destroy(&p->te_avtab); @@ -1618,7 +1629,10 @@ static int type_bounds_sanity_check(void *key, void *datum, void *datap) return -EINVAL; } - upper = p->type_val_to_struct[upper->bounds - 1]; + upper = flex_array_get_ptr(p->type_val_to_struct_array, + upper->bounds - 1); + BUG_ON(!upper); + if (upper->attribute) { printk(KERN_ERR "SELinux: type %s: " "bounded by attribute %s", diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h index 95d3d7de361e..9826a92a6b0c 100644 --- a/security/selinux/ss/policydb.h +++ b/security/selinux/ss/policydb.h @@ -217,7 +217,7 @@ struct policydb { struct class_datum **class_val_to_struct; struct role_datum **role_val_to_struct; struct user_datum **user_val_to_struct; - struct type_datum **type_val_to_struct; + struct flex_array *type_val_to_struct_array; /* type enforcement access vectors and transitions */ struct avtab te_avtab; diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index ab6dbce5fd2a..afcbc19817f7 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -530,12 +530,18 @@ static void type_attribute_bounds_av(struct context *scontext, struct context lo_scontext; struct context lo_tcontext; struct av_decision lo_avd; - struct type_datum *source - = policydb.type_val_to_struct[scontext->type - 1]; - struct type_datum *target - = policydb.type_val_to_struct[tcontext->type - 1]; + struct type_datum *source; + struct type_datum *target; u32 masked = 0; + source = flex_array_get_ptr(policydb.type_val_to_struct_array, + scontext->type - 1); + BUG_ON(!source); + + target = flex_array_get_ptr(policydb.type_val_to_struct_array, + tcontext->type - 1); + BUG_ON(!target); + if (source->bounds) { memset(&lo_avd, 0, sizeof(lo_avd)); @@ -828,7 +834,8 @@ int security_bounded_transition(u32 old_sid, u32 new_sid) index = new_context->type; while (true) { - type = policydb.type_val_to_struct[index - 1]; + type = flex_array_get_ptr(policydb.type_val_to_struct_array, + index - 1); BUG_ON(!type); /* not bounded anymore */ |