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Diffstat (limited to 'fs/exec.c')
-rw-r--r--fs/exec.c166
1 files changed, 83 insertions, 83 deletions
diff --git a/fs/exec.c b/fs/exec.c
index c5c24f2fc44a..7ea097f6b341 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -74,6 +74,8 @@ static DEFINE_RWLOCK(binfmt_lock);
void __register_binfmt(struct linux_binfmt * fmt, int insert)
{
BUG_ON(!fmt);
+ if (WARN_ON(!fmt->load_binary))
+ return;
write_lock(&binfmt_lock);
insert ? list_add(&fmt->lh, &formats) :
list_add_tail(&fmt->lh, &formats);
@@ -104,6 +106,7 @@ static inline void put_binfmt(struct linux_binfmt * fmt)
*/
SYSCALL_DEFINE1(uselib, const char __user *, library)
{
+ struct linux_binfmt *fmt;
struct file *file;
struct filename *tmp = getname(library);
int error = PTR_ERR(tmp);
@@ -134,24 +137,21 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
fsnotify_open(file);
error = -ENOEXEC;
- if(file->f_op) {
- struct linux_binfmt * fmt;
- read_lock(&binfmt_lock);
- list_for_each_entry(fmt, &formats, lh) {
- if (!fmt->load_shlib)
- continue;
- if (!try_module_get(fmt->module))
- continue;
- read_unlock(&binfmt_lock);
- error = fmt->load_shlib(file);
- read_lock(&binfmt_lock);
- put_binfmt(fmt);
- if (error != -ENOEXEC)
- break;
- }
+ read_lock(&binfmt_lock);
+ list_for_each_entry(fmt, &formats, lh) {
+ if (!fmt->load_shlib)
+ continue;
+ if (!try_module_get(fmt->module))
+ continue;
read_unlock(&binfmt_lock);
+ error = fmt->load_shlib(file);
+ read_lock(&binfmt_lock);
+ put_binfmt(fmt);
+ if (error != -ENOEXEC)
+ break;
}
+ read_unlock(&binfmt_lock);
exit:
fput(file);
out:
@@ -266,7 +266,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP);
vma->vm_end = STACK_TOP_MAX;
vma->vm_start = vma->vm_end - PAGE_SIZE;
- vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
+ vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
INIT_LIST_HEAD(&vma->anon_vma_chain);
@@ -1275,13 +1275,10 @@ static int check_unsafe_exec(struct linux_binprm *bprm)
*/
int prepare_binprm(struct linux_binprm *bprm)
{
- umode_t mode;
- struct inode * inode = file_inode(bprm->file);
+ struct inode *inode = file_inode(bprm->file);
+ umode_t mode = inode->i_mode;
int retval;
- mode = inode->i_mode;
- if (bprm->file->f_op == NULL)
- return -EACCES;
/* clear any previous set[ug]id data from a previous binary */
bprm->cred->euid = current_euid();
@@ -1365,90 +1362,86 @@ out:
}
EXPORT_SYMBOL(remove_arg_zero);
+#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
/*
* cycle the list of binary formats handler, until one recognizes the image
*/
int search_binary_handler(struct linux_binprm *bprm)
{
- unsigned int depth = bprm->recursion_depth;
- int try,retval;
+ bool need_retry = IS_ENABLED(CONFIG_MODULES);
struct linux_binfmt *fmt;
- pid_t old_pid, old_vpid;
+ int retval;
/* This allows 4 levels of binfmt rewrites before failing hard. */
- if (depth > 5)
+ if (bprm->recursion_depth > 5)
return -ELOOP;
retval = security_bprm_check(bprm);
if (retval)
return retval;
+ retval = -ENOENT;
+ retry:
+ read_lock(&binfmt_lock);
+ list_for_each_entry(fmt, &formats, lh) {
+ if (!try_module_get(fmt->module))
+ continue;
+ read_unlock(&binfmt_lock);
+ bprm->recursion_depth++;
+ retval = fmt->load_binary(bprm);
+ bprm->recursion_depth--;
+ if (retval >= 0 || retval != -ENOEXEC ||
+ bprm->mm == NULL || bprm->file == NULL) {
+ put_binfmt(fmt);
+ return retval;
+ }
+ read_lock(&binfmt_lock);
+ put_binfmt(fmt);
+ }
+ read_unlock(&binfmt_lock);
+
+ if (need_retry && retval == -ENOEXEC) {
+ if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
+ printable(bprm->buf[2]) && printable(bprm->buf[3]))
+ return retval;
+ if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)
+ return retval;
+ need_retry = false;
+ goto retry;
+ }
+
+ return retval;
+}
+EXPORT_SYMBOL(search_binary_handler);
+
+static int exec_binprm(struct linux_binprm *bprm)
+{
+ pid_t old_pid, old_vpid;
+ int ret;
+
/* Need to fetch pid before load_binary changes it */
old_pid = current->pid;
rcu_read_lock();
old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent));
rcu_read_unlock();
- retval = -ENOENT;
- for (try=0; try<2; try++) {
- read_lock(&binfmt_lock);
- list_for_each_entry(fmt, &formats, lh) {
- int (*fn)(struct linux_binprm *) = fmt->load_binary;
- if (!fn)
- continue;
- if (!try_module_get(fmt->module))
- continue;
- read_unlock(&binfmt_lock);
- bprm->recursion_depth = depth + 1;
- retval = fn(bprm);
- bprm->recursion_depth = depth;
- if (retval >= 0) {
- if (depth == 0) {
- audit_bprm(bprm);
- trace_sched_process_exec(current, old_pid, bprm);
- ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
- }
- put_binfmt(fmt);
- allow_write_access(bprm->file);
- if (bprm->file)
- fput(bprm->file);
- bprm->file = NULL;
- current->did_exec = 1;
- proc_exec_connector(current);
- return retval;
- }
- read_lock(&binfmt_lock);
- put_binfmt(fmt);
- if (retval != -ENOEXEC || bprm->mm == NULL)
- break;
- if (!bprm->file) {
- read_unlock(&binfmt_lock);
- return retval;
- }
- }
- read_unlock(&binfmt_lock);
-#ifdef CONFIG_MODULES
- if (retval != -ENOEXEC || bprm->mm == NULL) {
- break;
- } else {
-#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
- if (printable(bprm->buf[0]) &&
- printable(bprm->buf[1]) &&
- printable(bprm->buf[2]) &&
- printable(bprm->buf[3]))
- break; /* -ENOEXEC */
- if (try)
- break; /* -ENOEXEC */
- request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));
+ ret = search_binary_handler(bprm);
+ if (ret >= 0) {
+ audit_bprm(bprm);
+ trace_sched_process_exec(current, old_pid, bprm);
+ ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
+ current->did_exec = 1;
+ proc_exec_connector(current);
+
+ if (bprm->file) {
+ allow_write_access(bprm->file);
+ fput(bprm->file);
+ bprm->file = NULL; /* to catch use-after-free */
}
-#else
- break;
-#endif
}
- return retval;
-}
-EXPORT_SYMBOL(search_binary_handler);
+ return ret;
+}
/*
* sys_execve() executes a new program.
@@ -1538,7 +1531,7 @@ static int do_execve_common(const char *filename,
if (retval < 0)
goto out;
- retval = search_binary_handler(bprm);
+ retval = exec_binprm(bprm);
if (retval < 0)
goto out;
@@ -1546,6 +1539,7 @@ static int do_execve_common(const char *filename,
current->fs->in_exec = 0;
current->in_execve = 0;
acct_update_integrals(current);
+ task_numa_free(current);
free_bprm(bprm);
if (displaced)
put_files_struct(displaced);
@@ -1667,6 +1661,12 @@ int __get_dumpable(unsigned long mm_flags)
return (ret > SUID_DUMP_USER) ? SUID_DUMP_ROOT : ret;
}
+/*
+ * This returns the actual value of the suid_dumpable flag. For things
+ * that are using this for checking for privilege transitions, it must
+ * test against SUID_DUMP_USER rather than treating it as a boolean
+ * value.
+ */
int get_dumpable(struct mm_struct *mm)
{
return __get_dumpable(mm->flags);
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-02 12:32:43 +0000