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-rw-r--r--fs/exec.c264
1 files changed, 176 insertions, 88 deletions
diff --git a/fs/exec.c b/fs/exec.c
index e19de6a80339..99d33a1371e9 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -28,7 +28,6 @@
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
-#include <linux/smp_lock.h>
#include <linux/swap.h>
#include <linux/string.h>
#include <linux/init.h>
@@ -55,6 +54,7 @@
#include <linux/fsnotify.h>
#include <linux/fs_struct.h>
#include <linux/pipe_fs_i.h>
+#include <linux/oom.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
@@ -66,6 +66,12 @@ char core_pattern[CORENAME_MAX_SIZE] = "core";
unsigned int core_pipe_limit;
int suid_dumpable = 0;
+struct core_name {
+ char *corename;
+ int used, size;
+};
+static atomic_t call_count = ATOMIC_INIT(1);
+
/* The maximal length of core_pattern is also specified in sysctl.c */
static LIST_HEAD(formats);
@@ -129,7 +135,7 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
if (file->f_path.mnt->mnt_flags & MNT_NOEXEC)
goto exit;
- fsnotify_open(file->f_path.dentry);
+ fsnotify_open(file);
error = -ENOEXEC;
if(file->f_op) {
@@ -362,13 +368,13 @@ err:
/*
* count() counts the number of strings in array ARGV.
*/
-static int count(char __user * __user * argv, int max)
+static int count(const char __user * const __user * argv, int max)
{
int i = 0;
if (argv != NULL) {
for (;;) {
- char __user * p;
+ const char __user * p;
if (get_user(p, argv))
return -EFAULT;
@@ -377,6 +383,9 @@ static int count(char __user * __user * argv, int max)
argv++;
if (i++ >= max)
return -E2BIG;
+
+ if (fatal_signal_pending(current))
+ return -ERESTARTNOHAND;
cond_resched();
}
}
@@ -388,7 +397,7 @@ static int count(char __user * __user * argv, int max)
* processes's memory to the new process's stack. The call to get_user_pages()
* ensures the destination page is created and not swapped out.
*/
-static int copy_strings(int argc, char __user * __user * argv,
+static int copy_strings(int argc, const char __user *const __user *argv,
struct linux_binprm *bprm)
{
struct page *kmapped_page = NULL;
@@ -397,7 +406,7 @@ static int copy_strings(int argc, char __user * __user * argv,
int ret;
while (argc-- > 0) {
- char __user *str;
+ const char __user *str;
int len;
unsigned long pos;
@@ -420,6 +429,12 @@ static int copy_strings(int argc, char __user * __user * argv,
while (len > 0) {
int offset, bytes_to_copy;
+ if (fatal_signal_pending(current)) {
+ ret = -ERESTARTNOHAND;
+ goto out;
+ }
+ cond_resched();
+
offset = pos % PAGE_SIZE;
if (offset == 0)
offset = PAGE_SIZE;
@@ -471,12 +486,13 @@ out:
/*
* Like copy_strings, but get argv and its values from kernel memory.
*/
-int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm)
+int copy_strings_kernel(int argc, const char *const *argv,
+ struct linux_binprm *bprm)
{
int r;
mm_segment_t oldfs = get_fs();
set_fs(KERNEL_DS);
- r = copy_strings(argc, (char __user * __user *)argv, bprm);
+ r = copy_strings(argc, (const char __user *const __user *)argv, bprm);
set_fs(oldfs);
return r;
}
@@ -594,6 +610,11 @@ int setup_arg_pages(struct linux_binprm *bprm,
#else
stack_top = arch_align_stack(stack_top);
stack_top = PAGE_ALIGN(stack_top);
+
+ if (unlikely(stack_top < mmap_min_addr) ||
+ unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr))
+ return -ENOMEM;
+
stack_shift = vma->vm_end - stack_top;
bprm->p -= stack_shift;
@@ -653,6 +674,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
else
stack_base = vma->vm_start - stack_expand;
#endif
+ current->mm->start_stack = bprm->p;
ret = expand_stack(vma, stack_base);
if (ret)
ret = -EFAULT;
@@ -683,7 +705,7 @@ struct file *open_exec(const char *name)
if (file->f_path.mnt->mnt_flags & MNT_NOEXEC)
goto exit;
- fsnotify_open(file->f_path.dentry);
+ fsnotify_open(file);
err = deny_write_access(file);
if (err)
@@ -744,6 +766,10 @@ static int exec_mmap(struct mm_struct *mm)
tsk->mm = mm;
tsk->active_mm = mm;
activate_mm(active_mm, mm);
+ if (old_mm && tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) {
+ atomic_dec(&old_mm->oom_disable_count);
+ atomic_inc(&tsk->mm->oom_disable_count);
+ }
task_unlock(tsk);
arch_pick_mmap_layout(mm);
if (old_mm) {
@@ -983,7 +1009,7 @@ int flush_old_exec(struct linux_binprm * bprm)
bprm->mm = NULL; /* We're using it now */
- current->flags &= ~PF_RANDOMIZE;
+ current->flags &= ~(PF_RANDOMIZE | PF_KTHREAD);
flush_thread();
current->personality &= ~bprm->per_clear;
@@ -997,7 +1023,7 @@ EXPORT_SYMBOL(flush_old_exec);
void setup_new_exec(struct linux_binprm * bprm)
{
int i, ch;
- char * name;
+ const char *name;
char tcomm[sizeof(current->comm)];
arch_pick_mmap_layout(current->mm);
@@ -1063,14 +1089,14 @@ EXPORT_SYMBOL(setup_new_exec);
*/
int prepare_bprm_creds(struct linux_binprm *bprm)
{
- if (mutex_lock_interruptible(&current->cred_guard_mutex))
+ if (mutex_lock_interruptible(&current->signal->cred_guard_mutex))
return -ERESTARTNOINTR;
bprm->cred = prepare_exec_creds();
if (likely(bprm->cred))
return 0;
- mutex_unlock(&current->cred_guard_mutex);
+ mutex_unlock(&current->signal->cred_guard_mutex);
return -ENOMEM;
}
@@ -1078,7 +1104,7 @@ void free_bprm(struct linux_binprm *bprm)
{
free_arg_pages(bprm);
if (bprm->cred) {
- mutex_unlock(&current->cred_guard_mutex);
+ mutex_unlock(&current->signal->cred_guard_mutex);
abort_creds(bprm->cred);
}
kfree(bprm);
@@ -1099,13 +1125,13 @@ void install_exec_creds(struct linux_binprm *bprm)
* credentials; any time after this it may be unlocked.
*/
security_bprm_committed_creds(bprm);
- mutex_unlock(&current->cred_guard_mutex);
+ mutex_unlock(&current->signal->cred_guard_mutex);
}
EXPORT_SYMBOL(install_exec_creds);
/*
* determine how safe it is to execute the proposed program
- * - the caller must hold current->cred_guard_mutex to protect against
+ * - the caller must hold ->cred_guard_mutex to protect against
* PTRACE_ATTACH
*/
int check_unsafe_exec(struct linux_binprm *bprm)
@@ -1117,7 +1143,7 @@ int check_unsafe_exec(struct linux_binprm *bprm)
bprm->unsafe = tracehook_unsafe_exec(p);
n_fs = 1;
- write_lock(&p->fs->lock);
+ spin_lock(&p->fs->lock);
rcu_read_lock();
for (t = next_thread(p); t != p; t = next_thread(t)) {
if (t->fs == p->fs)
@@ -1134,7 +1160,7 @@ int check_unsafe_exec(struct linux_binprm *bprm)
res = 1;
}
}
- write_unlock(&p->fs->lock);
+ spin_unlock(&p->fs->lock);
return res;
}
@@ -1316,9 +1342,9 @@ EXPORT_SYMBOL(search_binary_handler);
/*
* sys_execve() executes a new program.
*/
-int do_execve(char * filename,
- char __user *__user *argv,
- char __user *__user *envp,
+int do_execve(const char * filename,
+ const char __user *const __user *argv,
+ const char __user *const __user *envp,
struct pt_regs * regs)
{
struct linux_binprm *bprm;
@@ -1386,7 +1412,6 @@ int do_execve(char * filename,
if (retval < 0)
goto out;
- current->flags &= ~PF_KTHREAD;
retval = search_binary_handler(bprm,regs);
if (retval < 0)
goto out;
@@ -1439,127 +1464,148 @@ void set_binfmt(struct linux_binfmt *new)
EXPORT_SYMBOL(set_binfmt);
+static int expand_corename(struct core_name *cn)
+{
+ char *old_corename = cn->corename;
+
+ cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count);
+ cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL);
+
+ if (!cn->corename) {
+ kfree(old_corename);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int cn_printf(struct core_name *cn, const char *fmt, ...)
+{
+ char *cur;
+ int need;
+ int ret;
+ va_list arg;
+
+ va_start(arg, fmt);
+ need = vsnprintf(NULL, 0, fmt, arg);
+ va_end(arg);
+
+ if (likely(need < cn->size - cn->used - 1))
+ goto out_printf;
+
+ ret = expand_corename(cn);
+ if (ret)
+ goto expand_fail;
+
+out_printf:
+ cur = cn->corename + cn->used;
+ va_start(arg, fmt);
+ vsnprintf(cur, need + 1, fmt, arg);
+ va_end(arg);
+ cn->used += need;
+ return 0;
+
+expand_fail:
+ return ret;
+}
+
/* format_corename will inspect the pattern parameter, and output a
* name into corename, which must have space for at least
* CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
*/
-static int format_corename(char *corename, long signr)
+static int format_corename(struct core_name *cn, long signr)
{
const struct cred *cred = current_cred();
const char *pat_ptr = core_pattern;
int ispipe = (*pat_ptr == '|');
- char *out_ptr = corename;
- char *const out_end = corename + CORENAME_MAX_SIZE;
- int rc;
int pid_in_pattern = 0;
+ int err = 0;
+
+ cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count);
+ cn->corename = kmalloc(cn->size, GFP_KERNEL);
+ cn->used = 0;
+
+ if (!cn->corename)
+ return -ENOMEM;
/* Repeat as long as we have more pattern to process and more output
space */
while (*pat_ptr) {
if (*pat_ptr != '%') {
- if (out_ptr == out_end)
+ if (*pat_ptr == 0)
goto out;
- *out_ptr++ = *pat_ptr++;
+ err = cn_printf(cn, "%c", *pat_ptr++);
} else {
switch (*++pat_ptr) {
+ /* single % at the end, drop that */
case 0:
goto out;
/* Double percent, output one percent */
case '%':
- if (out_ptr == out_end)
- goto out;
- *out_ptr++ = '%';
+ err = cn_printf(cn, "%c", '%');
break;
/* pid */
case 'p':
pid_in_pattern = 1;
- rc = snprintf(out_ptr, out_end - out_ptr,
- "%d", task_tgid_vnr(current));
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
+ err = cn_printf(cn, "%d",
+ task_tgid_vnr(current));
break;
/* uid */
case 'u':
- rc = snprintf(out_ptr, out_end - out_ptr,
- "%d", cred->uid);
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
+ err = cn_printf(cn, "%d", cred->uid);
break;
/* gid */
case 'g':
- rc = snprintf(out_ptr, out_end - out_ptr,
- "%d", cred->gid);
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
+ err = cn_printf(cn, "%d", cred->gid);
break;
/* signal that caused the coredump */
case 's':
- rc = snprintf(out_ptr, out_end - out_ptr,
- "%ld", signr);
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
+ err = cn_printf(cn, "%ld", signr);
break;
/* UNIX time of coredump */
case 't': {
struct timeval tv;
do_gettimeofday(&tv);
- rc = snprintf(out_ptr, out_end - out_ptr,
- "%lu", tv.tv_sec);
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
+ err = cn_printf(cn, "%lu", tv.tv_sec);
break;
}
/* hostname */
case 'h':
down_read(&uts_sem);
- rc = snprintf(out_ptr, out_end - out_ptr,
- "%s", utsname()->nodename);
+ err = cn_printf(cn, "%s",
+ utsname()->nodename);
up_read(&uts_sem);
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
break;
/* executable */
case 'e':
- rc = snprintf(out_ptr, out_end - out_ptr,
- "%s", current->comm);
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
+ err = cn_printf(cn, "%s", current->comm);
break;
/* core limit size */
case 'c':
- rc = snprintf(out_ptr, out_end - out_ptr,
- "%lu", rlimit(RLIMIT_CORE));
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
+ err = cn_printf(cn, "%lu",
+ rlimit(RLIMIT_CORE));
break;
default:
break;
}
++pat_ptr;
}
+
+ if (err)
+ return err;
}
+
/* Backward compatibility with core_uses_pid:
*
* If core_pattern does not include a %p (as is the default)
* and core_uses_pid is set, then .%pid will be appended to
* the filename. Do not do this for piped commands. */
if (!ispipe && !pid_in_pattern && core_uses_pid) {
- rc = snprintf(out_ptr, out_end - out_ptr,
- ".%d", task_tgid_vnr(current));
- if (rc > out_end - out_ptr)
- goto out;
- out_ptr += rc;
+ err = cn_printf(cn, ".%d", task_tgid_vnr(current));
+ if (err)
+ return err;
}
out:
- *out_ptr = 0;
return ispipe;
}
@@ -1836,7 +1882,7 @@ static int umh_pipe_setup(struct subprocess_info *info)
void do_coredump(long signr, int exit_code, struct pt_regs *regs)
{
struct core_state core_state;
- char corename[CORENAME_MAX_SIZE + 1];
+ struct core_name cn;
struct mm_struct *mm = current->mm;
struct linux_binfmt * binfmt;
const struct cred *old_cred;
@@ -1891,13 +1937,13 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
*/
clear_thread_flag(TIF_SIGPENDING);
- /*
- * lock_kernel() because format_corename() is controlled by sysctl, which
- * uses lock_kernel()
- */
- lock_kernel();
- ispipe = format_corename(corename, signr);
- unlock_kernel();
+ ispipe = format_corename(&cn, signr);
+
+ if (ispipe == -ENOMEM) {
+ printk(KERN_WARNING "format_corename failed\n");
+ printk(KERN_WARNING "Aborting core\n");
+ goto fail_corename;
+ }
if (ispipe) {
int dump_count;
@@ -1934,7 +1980,7 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
goto fail_dropcount;
}
- helper_argv = argv_split(GFP_KERNEL, corename+1, NULL);
+ helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL);
if (!helper_argv) {
printk(KERN_WARNING "%s failed to allocate memory\n",
__func__);
@@ -1947,7 +1993,7 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
argv_free(helper_argv);
if (retval) {
printk(KERN_INFO "Core dump to %s pipe failed\n",
- corename);
+ cn.corename);
goto close_fail;
}
} else {
@@ -1956,7 +2002,7 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
if (cprm.limit < binfmt->min_coredump)
goto fail_unlock;
- cprm.file = filp_open(corename,
+ cprm.file = filp_open(cn.corename,
O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
0600);
if (IS_ERR(cprm.file))
@@ -1998,6 +2044,8 @@ fail_dropcount:
if (ispipe)
atomic_dec(&core_dump_count);
fail_unlock:
+ kfree(cn.corename);
+fail_corename:
coredump_finish(mm);
revert_creds(old_cred);
fail_creds:
@@ -2005,3 +2053,43 @@ fail_creds:
fail:
return;
}
+
+/*
+ * Core dumping helper functions. These are the only things you should
+ * do on a core-file: use only these functions to write out all the
+ * necessary info.
+ */
+int dump_write(struct file *file, const void *addr, int nr)
+{
+ return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
+}
+EXPORT_SYMBOL(dump_write);
+
+int dump_seek(struct file *file, loff_t off)
+{
+ int ret = 1;
+
+ if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
+ if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
+ return 0;
+ } else {
+ char *buf = (char *)get_zeroed_page(GFP_KERNEL);
+
+ if (!buf)
+ return 0;
+ while (off > 0) {
+ unsigned long n = off;
+
+ if (n > PAGE_SIZE)
+ n = PAGE_SIZE;
+ if (!dump_write(file, buf, n)) {
+ ret = 0;
+ break;
+ }
+ off -= n;
+ }
+ free_page((unsigned long)buf);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(dump_seek);
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-06-03 14:56:25 +0200