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-rw-r--r--kernel/module.c90
1 files changed, 76 insertions, 14 deletions
diff --git a/kernel/module.c b/kernel/module.c
index e797812a4d95..e4ab36ce7672 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -18,6 +18,7 @@
*/
#include <linux/module.h>
#include <linux/moduleloader.h>
+#include <linux/ftrace_event.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
@@ -52,6 +53,7 @@
#include <linux/ftrace.h>
#include <linux/async.h>
#include <linux/percpu.h>
+#include <linux/kmemleak.h>
#if 0
#define DEBUGP printk
@@ -72,6 +74,9 @@ DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
static LIST_HEAD(modules);
+/* Block module loading/unloading? */
+int modules_disabled = 0;
+
/* Waiting for a module to finish initializing? */
static DECLARE_WAIT_QUEUE_HEAD(module_wq);
@@ -429,6 +434,7 @@ static void *percpu_modalloc(unsigned long size, unsigned long align,
unsigned long extra;
unsigned int i;
void *ptr;
+ int cpu;
if (align > PAGE_SIZE) {
printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
@@ -458,6 +464,11 @@ static void *percpu_modalloc(unsigned long size, unsigned long align,
if (!split_block(i, size))
return NULL;
+ /* add the per-cpu scanning areas */
+ for_each_possible_cpu(cpu)
+ kmemleak_alloc(ptr + per_cpu_offset(cpu), size, 0,
+ GFP_KERNEL);
+
/* Mark allocated */
pcpu_size[i] = -pcpu_size[i];
return ptr;
@@ -472,6 +483,7 @@ static void percpu_modfree(void *freeme)
{
unsigned int i;
void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
+ int cpu;
/* First entry is core kernel percpu data. */
for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
@@ -483,6 +495,10 @@ static void percpu_modfree(void *freeme)
BUG();
free:
+ /* remove the per-cpu scanning areas */
+ for_each_possible_cpu(cpu)
+ kmemleak_free(freeme + per_cpu_offset(cpu));
+
/* Merge with previous? */
if (pcpu_size[i-1] >= 0) {
pcpu_size[i-1] += pcpu_size[i];
@@ -777,7 +793,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
char name[MODULE_NAME_LEN];
int ret, forced = 0;
- if (!capable(CAP_SYS_MODULE))
+ if (!capable(CAP_SYS_MODULE) || modules_disabled)
return -EPERM;
if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0)
@@ -1489,9 +1505,6 @@ static void free_module(struct module *mod)
/* Free any allocated parameters. */
destroy_params(mod->kp, mod->num_kp);
- /* release any pointers to mcount in this module */
- ftrace_release(mod->module_core, mod->core_size);
-
/* This may be NULL, but that's OK */
module_free(mod, mod->module_init);
kfree(mod->args);
@@ -1878,6 +1891,36 @@ static void *module_alloc_update_bounds(unsigned long size)
return ret;
}
+#ifdef CONFIG_DEBUG_KMEMLEAK
+static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
+ Elf_Shdr *sechdrs, char *secstrings)
+{
+ unsigned int i;
+
+ /* only scan the sections containing data */
+ kmemleak_scan_area(mod->module_core, (unsigned long)mod -
+ (unsigned long)mod->module_core,
+ sizeof(struct module), GFP_KERNEL);
+
+ for (i = 1; i < hdr->e_shnum; i++) {
+ if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+ continue;
+ if (strncmp(secstrings + sechdrs[i].sh_name, ".data", 5) != 0
+ && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
+ continue;
+
+ kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr -
+ (unsigned long)mod->module_core,
+ sechdrs[i].sh_size, GFP_KERNEL);
+ }
+}
+#else
+static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
+ Elf_Shdr *sechdrs, char *secstrings)
+{
+}
+#endif
+
/* Allocate and load the module: note that size of section 0 is always
zero, and we rely on this for optional sections. */
static noinline struct module *load_module(void __user *umod,
@@ -1892,11 +1935,9 @@ static noinline struct module *load_module(void __user *umod,
unsigned int symindex = 0;
unsigned int strindex = 0;
unsigned int modindex, versindex, infoindex, pcpuindex;
- unsigned int num_mcount;
struct module *mod;
long err = 0;
void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
- unsigned long *mseg;
mm_segment_t old_fs;
DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
@@ -2050,6 +2091,12 @@ static noinline struct module *load_module(void __user *umod,
/* Do the allocs. */
ptr = module_alloc_update_bounds(mod->core_size);
+ /*
+ * The pointer to this block is stored in the module structure
+ * which is inside the block. Just mark it as not being a
+ * leak.
+ */
+ kmemleak_not_leak(ptr);
if (!ptr) {
err = -ENOMEM;
goto free_percpu;
@@ -2058,6 +2105,13 @@ static noinline struct module *load_module(void __user *umod,
mod->module_core = ptr;
ptr = module_alloc_update_bounds(mod->init_size);
+ /*
+ * The pointer to this block is stored in the module structure
+ * which is inside the block. This block doesn't need to be
+ * scanned as it contains data and code that will be freed
+ * after the module is initialized.
+ */
+ kmemleak_ignore(ptr);
if (!ptr && mod->init_size) {
err = -ENOMEM;
goto free_core;
@@ -2088,6 +2142,7 @@ static noinline struct module *load_module(void __user *umod,
}
/* Module has been moved. */
mod = (void *)sechdrs[modindex].sh_addr;
+ kmemleak_load_module(mod, hdr, sechdrs, secstrings);
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
@@ -2172,7 +2227,19 @@ static noinline struct module *load_module(void __user *umod,
sizeof(*mod->tracepoints),
&mod->num_tracepoints);
#endif
-
+#ifdef CONFIG_EVENT_TRACING
+ mod->trace_events = section_objs(hdr, sechdrs, secstrings,
+ "_ftrace_events",
+ sizeof(*mod->trace_events),
+ &mod->num_trace_events);
+#endif
+#ifdef CONFIG_FTRACE_MCOUNT_RECORD
+ /* sechdrs[0].sh_size is always zero */
+ mod->ftrace_callsites = section_objs(hdr, sechdrs, secstrings,
+ "__mcount_loc",
+ sizeof(*mod->ftrace_callsites),
+ &mod->num_ftrace_callsites);
+#endif
#ifdef CONFIG_MODVERSIONS
if ((mod->num_syms && !mod->crcs)
|| (mod->num_gpl_syms && !mod->gpl_crcs)
@@ -2237,11 +2304,6 @@ static noinline struct module *load_module(void __user *umod,
dynamic_debug_setup(debug, num_debug);
}
- /* sechdrs[0].sh_size is always zero */
- mseg = section_objs(hdr, sechdrs, secstrings, "__mcount_loc",
- sizeof(*mseg), &num_mcount);
- ftrace_init_module(mod, mseg, mseg + num_mcount);
-
err = module_finalize(hdr, sechdrs, mod);
if (err < 0)
goto cleanup;
@@ -2302,7 +2364,6 @@ static noinline struct module *load_module(void __user *umod,
cleanup:
kobject_del(&mod->mkobj.kobj);
kobject_put(&mod->mkobj.kobj);
- ftrace_release(mod->module_core, mod->core_size);
free_unload:
module_unload_free(mod);
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
@@ -2336,7 +2397,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
int ret = 0;
/* Must have permission */
- if (!capable(CAP_SYS_MODULE))
+ if (!capable(CAP_SYS_MODULE) || modules_disabled)
return -EPERM;
/* Only one module load at a time, please */
@@ -2394,6 +2455,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
mutex_lock(&module_mutex);
/* Drop initial reference. */
module_put(mod);
+ trim_init_extable(mod);
module_free(mod, mod->module_init);
mod->module_init = NULL;
mod->init_size = 0;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.