| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20240306182440.2003814-13-surenb@google.com>
Date: Wed, 6 Mar 2024 10:24:10 -0800
From: Suren Baghdasaryan <surenb@...gle.com>
To: akpm@...ux-foundation.org
Cc: kent.overstreet@...ux.dev, mhocko@...e.com, vbabka@...e.cz,
hannes@...xchg.org, roman.gushchin@...ux.dev, mgorman@...e.de,
dave@...olabs.net, willy@...radead.org, liam.howlett@...cle.com,
penguin-kernel@...ove.sakura.ne.jp, corbet@....net, void@...ifault.com,
peterz@...radead.org, juri.lelli@...hat.com, catalin.marinas@....com,
will@...nel.org, arnd@...db.de, tglx@...utronix.de, mingo@...hat.com,
dave.hansen@...ux.intel.com, x86@...nel.org, peterx@...hat.com,
david@...hat.com, axboe@...nel.dk, mcgrof@...nel.org, masahiroy@...nel.org,
nathan@...nel.org, dennis@...nel.org, jhubbard@...dia.com, tj@...nel.org,
muchun.song@...ux.dev, rppt@...nel.org, paulmck@...nel.org,
pasha.tatashin@...een.com, yosryahmed@...gle.com, yuzhao@...gle.com,
dhowells@...hat.com, hughd@...gle.com, andreyknvl@...il.com,
keescook@...omium.org, ndesaulniers@...gle.com, vvvvvv@...gle.com,
gregkh@...uxfoundation.org, ebiggers@...gle.com, ytcoode@...il.com,
vincent.guittot@...aro.org, dietmar.eggemann@....com, rostedt@...dmis.org,
bsegall@...gle.com, bristot@...hat.com, vschneid@...hat.com, cl@...ux.com,
penberg@...nel.org, iamjoonsoo.kim@....com, 42.hyeyoo@...il.com,
glider@...gle.com, elver@...gle.com, dvyukov@...gle.com, shakeelb@...gle.com,
songmuchun@...edance.com, jbaron@...mai.com, aliceryhl@...gle.com,
rientjes@...gle.com, minchan@...gle.com, kaleshsingh@...gle.com,
surenb@...gle.com, kernel-team@...roid.com, linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org, iommu@...ts.linux.dev,
linux-arch@...r.kernel.org, linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
linux-modules@...r.kernel.org, kasan-dev@...glegroups.com,
cgroups@...r.kernel.org
Subject: [PATCH v5 12/37] lib: prevent module unloading if memory is not freed
Skip freeing module's data section if there are non-zero allocation tags
because otherwise, once these allocations are freed, the access to their
code tag would cause UAF.
Signed-off-by: Suren Baghdasaryan <surenb@...gle.com>
---
include/linux/codetag.h | 6 +++---
kernel/module/main.c | 27 +++++++++++++++++++--------
lib/codetag.c | 11 ++++++++---
3 files changed, 30 insertions(+), 14 deletions(-)
diff --git a/include/linux/codetag.h b/include/linux/codetag.h
index c44f5b83f24d..bfd0ba5c4185 100644
--- a/include/linux/codetag.h
+++ b/include/linux/codetag.h
@@ -35,7 +35,7 @@ struct codetag_type_desc {
size_t tag_size;
void (*module_load)(struct codetag_type *cttype,
struct codetag_module *cmod);
- void (*module_unload)(struct codetag_type *cttype,
+ bool (*module_unload)(struct codetag_type *cttype,
struct codetag_module *cmod);
};
@@ -71,10 +71,10 @@ codetag_register_type(const struct codetag_type_desc *desc);
#if defined(CONFIG_CODE_TAGGING) && defined(CONFIG_MODULES)
void codetag_load_module(struct module *mod);
-void codetag_unload_module(struct module *mod);
+bool codetag_unload_module(struct module *mod);
#else
static inline void codetag_load_module(struct module *mod) {}
-static inline void codetag_unload_module(struct module *mod) {}
+static inline bool codetag_unload_module(struct module *mod) { return true; }
#endif
#endif /* _LINUX_CODETAG_H */
diff --git a/kernel/module/main.c b/kernel/module/main.c
index bf5a4afbe4c5..41c37ad3d16e 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1211,15 +1211,19 @@ static void *module_memory_alloc(unsigned int size, enum mod_mem_type type)
return module_alloc(size);
}
-static void module_memory_free(void *ptr, enum mod_mem_type type)
+static void module_memory_free(void *ptr, enum mod_mem_type type,
+ bool unload_codetags)
{
+ if (!unload_codetags && mod_mem_type_is_core_data(type))
+ return;
+
if (mod_mem_use_vmalloc(type))
vfree(ptr);
else
module_memfree(ptr);
}
-static void free_mod_mem(struct module *mod)
+static void free_mod_mem(struct module *mod, bool unload_codetags)
{
for_each_mod_mem_type(type) {
struct module_memory *mod_mem = &mod->mem[type];
@@ -1230,20 +1234,27 @@ static void free_mod_mem(struct module *mod)
/* Free lock-classes; relies on the preceding sync_rcu(). */
lockdep_free_key_range(mod_mem->base, mod_mem->size);
if (mod_mem->size)
- module_memory_free(mod_mem->base, type);
+ module_memory_free(mod_mem->base, type,
+ unload_codetags);
}
/* MOD_DATA hosts mod, so free it at last */
lockdep_free_key_range(mod->mem[MOD_DATA].base, mod->mem[MOD_DATA].size);
- module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA);
+ module_memory_free(mod->mem[MOD_DATA].base, MOD_DATA, unload_codetags);
}
/* Free a module, remove from lists, etc. */
static void free_module(struct module *mod)
{
+ bool unload_codetags;
+
trace_module_free(mod);
- codetag_unload_module(mod);
+ unload_codetags = codetag_unload_module(mod);
+ if (!unload_codetags)
+ pr_warn("%s: memory allocation(s) from the module still alive, cannot unload cleanly\n",
+ mod->name);
+
mod_sysfs_teardown(mod);
/*
@@ -1285,7 +1296,7 @@ static void free_module(struct module *mod)
kfree(mod->args);
percpu_modfree(mod);
- free_mod_mem(mod);
+ free_mod_mem(mod, unload_codetags);
}
void *__symbol_get(const char *symbol)
@@ -2298,7 +2309,7 @@ static int move_module(struct module *mod, struct load_info *info)
return 0;
out_enomem:
for (t--; t >= 0; t--)
- module_memory_free(mod->mem[t].base, t);
+ module_memory_free(mod->mem[t].base, t, true);
return ret;
}
@@ -2428,7 +2439,7 @@ static void module_deallocate(struct module *mod, struct load_info *info)
percpu_modfree(mod);
module_arch_freeing_init(mod);
- free_mod_mem(mod);
+ free_mod_mem(mod, true);
}
int __weak module_finalize(const Elf_Ehdr *hdr,
diff --git a/lib/codetag.c b/lib/codetag.c
index 54d2828eba25..408062f722ce 100644
--- a/lib/codetag.c
+++ b/lib/codetag.c
@@ -5,6 +5,7 @@
#include <linux/module.h>
#include <linux/seq_buf.h>
#include <linux/slab.h>
+#include <linux/vmalloc.h>
struct codetag_type {
struct list_head link;
@@ -206,12 +207,13 @@ void codetag_load_module(struct module *mod)
mutex_unlock(&codetag_lock);
}
-void codetag_unload_module(struct module *mod)
+bool codetag_unload_module(struct module *mod)
{
struct codetag_type *cttype;
+ bool unload_ok = true;
if (!mod)
- return;
+ return true;
mutex_lock(&codetag_lock);
list_for_each_entry(cttype, &codetag_types, link) {
@@ -228,7 +230,8 @@ void codetag_unload_module(struct module *mod)
}
if (found) {
if (cttype->desc.module_unload)
- cttype->desc.module_unload(cttype, cmod);
+ if (!cttype->desc.module_unload(cttype, cmod))
+ unload_ok = false;
cttype->count -= range_size(cttype, &cmod->range);
idr_remove(&cttype->mod_idr, mod_id);
@@ -237,6 +240,8 @@ void codetag_unload_module(struct module *mod)
up_write(&cttype->mod_lock);
}
mutex_unlock(&codetag_lock);
+
+ return unload_ok;
}
#else /* CONFIG_MODULES */
--
2.44.0.278.ge034bb2e1d-goog
Powered by blists - more mailing lists