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AJvYcCXDq5ASnICa7v5qZQki/6J0dZt918OwIIo48zpyOoBNrWwbzMZ51U2s435UFtiM5bg5CLJz+EEDLJHmZ3pJnG3YLAeYJY2LKuBV32O/+Q== X-Gm-Message-State: AOJu0YzfzzlKNnOlVuJBByzRjVeLkdyo7CwG7nY78wOdnCFVDNs2F4FN Hv8CWjHum4/oA9uVgoqfeDwfCZaaCMYWgX9lXvH2ykxwmy22yQlA4VklLRMqQfOMIq9mnvkvbZ+ kKA== X-Google-Smtp-Source: AGHT+IFD0XqCfLl4qYutYla1ZL6XgTrX5S7AO9uCahzWsTmMPZ4BnZi9haYMKld7cdjfFju71XrA0wuJzw0= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:201:953b:9a4e:1e10:3f07]) (user=surenb job=sendgmr) by 2002:a81:7956:0:b0:607:c633:2997 with SMTP id u83-20020a817956000000b00607c6332997mr4958335ywc.5.1708544484752; Wed, 21 Feb 2024 11:41:24 -0800 (PST) Date: Wed, 21 Feb 2024 11:40:26 -0800 In-Reply-To: <20240221194052.927623-1-surenb@google.com> Precedence: bulk X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240221194052.927623-1-surenb@google.com> X-Mailer: git-send-email 2.44.0.rc0.258.g7320e95886-goog Message-ID: <20240221194052.927623-14-surenb@google.com> Subject: [PATCH v4 13/36] lib: prevent module unloading if memory is not freed From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: kent.overstreet@linux.dev, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, roman.gushchin@linux.dev, mgorman@suse.de, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, penguin-kernel@i-love.sakura.ne.jp, corbet@lwn.net, void@manifault.com, peterz@infradead.org, juri.lelli@redhat.com, catalin.marinas@arm.com, will@kernel.org, arnd@arndb.de, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, peterx@redhat.com, david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org, nathan@kernel.org, dennis@kernel.org, tj@kernel.org, muchun.song@linux.dev, rppt@kernel.org, paulmck@kernel.org, pasha.tatashin@soleen.com, yosryahmed@google.com, yuzhao@google.com, dhowells@redhat.com, hughd@google.com, andreyknvl@gmail.com, keescook@chromium.org, ndesaulniers@google.com, vvvvvv@google.com, gregkh@linuxfoundation.org, ebiggers@google.com, ytcoode@gmail.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, bristot@redhat.com, vschneid@redhat.com, cl@linux.com, penberg@kernel.org, iamjoonsoo.kim@lge.com, 42.hyeyoo@gmail.com, glider@google.com, elver@google.com, dvyukov@google.com, shakeelb@google.com, songmuchun@bytedance.com, jbaron@akamai.com, rientjes@google.com, minchan@google.com, kaleshsingh@google.com, surenb@google.com, kernel-team@android.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, kasan-dev@googlegroups.com, cgroups@vger.kernel.org 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 --- include/linux/codetag.h | 6 +++--- kernel/module/main.c | 23 +++++++++++++++-------- lib/codetag.c | 11 ++++++++--- 3 files changed, 26 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 f400ba076cc7..658b631e76ad 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 +1234,23 @@ 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); mod_sysfs_teardown(mod); /* @@ -1285,7 +1292,7 @@ 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 +2305,7 @@ 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 +2435,7 @@ 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 9af22648dbfa..b13412ca57cc 100644 --- a/lib/codetag.c +++ b/lib/codetag.c @@ -5,6 +5,7 @@ #include #include #include +#include struct codetag_type { struct list_head link; @@ -239,12 +240,13 @@ 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) { @@ -261,7 +263,8 @@ 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); @@ -270,4 +273,6 @@ void codetag_unload_module(struct module *mod) up_write(&cttype->mod_lock); } mutex_unlock(&codetag_lock); + + return unload_ok; }