#include <linux/stat.h>
#include <linux/fcntl.h>
#include <linux/smp_lock.h>
+#include <linux/string.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/tsacct_kern.h>
#include <linux/cn_proc.h>
#include <linux/audit.h>
-#include <linux/signalfd.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
EXPORT_SYMBOL(suid_dumpable);
/* The maximal length of core_pattern is also specified in sysctl.c */
-static struct linux_binfmt *formats;
+static LIST_HEAD(formats);
static DEFINE_RWLOCK(binfmt_lock);
int register_binfmt(struct linux_binfmt * fmt)
{
- struct linux_binfmt ** tmp = &formats;
-
if (!fmt)
return -EINVAL;
- if (fmt->next)
- return -EBUSY;
write_lock(&binfmt_lock);
- while (*tmp) {
- if (fmt == *tmp) {
- write_unlock(&binfmt_lock);
- return -EBUSY;
- }
- tmp = &(*tmp)->next;
- }
- fmt->next = formats;
- formats = fmt;
+ list_add(&fmt->lh, &formats);
write_unlock(&binfmt_lock);
return 0;
}
EXPORT_SYMBOL(register_binfmt);
-int unregister_binfmt(struct linux_binfmt * fmt)
+void unregister_binfmt(struct linux_binfmt * fmt)
{
- struct linux_binfmt ** tmp = &formats;
-
write_lock(&binfmt_lock);
- while (*tmp) {
- if (fmt == *tmp) {
- *tmp = fmt->next;
- fmt->next = NULL;
- write_unlock(&binfmt_lock);
- return 0;
- }
- tmp = &(*tmp)->next;
- }
+ list_del(&fmt->lh);
write_unlock(&binfmt_lock);
- return -EINVAL;
}
EXPORT_SYMBOL(unregister_binfmt);
if (error)
goto out;
- error = -EACCES;
- if (nd.mnt->mnt_flags & MNT_NOEXEC)
- goto exit;
error = -EINVAL;
if (!S_ISREG(nd.dentry->d_inode->i_mode))
goto exit;
struct linux_binfmt * fmt;
read_lock(&binfmt_lock);
- for (fmt = formats ; fmt ; fmt = fmt->next) {
+ list_for_each_entry(fmt, &formats, lh) {
if (!fmt->load_shlib)
continue;
if (!try_module_get(fmt->module))
if (!err) {
struct inode *inode = nd.dentry->d_inode;
file = ERR_PTR(-EACCES);
- if (!(nd.mnt->mnt_flags & MNT_NOEXEC) &&
- S_ISREG(inode->i_mode)) {
+ if (S_ISREG(inode->i_mode)) {
int err = vfs_permission(&nd, MAY_EXEC);
file = ERR_PTR(err);
if (!err) {
struct task_struct *leader = NULL;
int count;
- /*
- * Tell all the sighand listeners that this sighand has
- * been detached. The signalfd_detach() function grabs the
- * sighand lock, if signal listeners are present on the sighand.
- */
- signalfd_detach(tsk);
-
/*
* If we don't share sighandlers, then we aren't sharing anything
* and we can just re-use it all.
*/
if (atomic_read(&oldsighand->count) <= 1) {
- BUG_ON(atomic_read(&sig->count) != 1);
exit_itimers(sig);
return 0;
}
if (leader)
release_task(leader);
- BUG_ON(atomic_read(&sig->count) != 1);
-
if (atomic_read(&oldsighand->count) == 1) {
/*
* Now that we nuked the rest of the thread group,
write_lock_irq(&tasklist_lock);
spin_lock(&oldsighand->siglock);
- spin_lock_nested(&newsighand->siglock, SINGLE_DEPTH_NESTING);
-
rcu_assign_pointer(tsk->sighand, newsighand);
- recalc_sigpending();
-
- spin_unlock(&newsighand->siglock);
spin_unlock(&oldsighand->siglock);
write_unlock_irq(&tasklist_lock);
BUG_ON(!thread_group_leader(tsk));
return 0;
}
-
+
/*
* These functions flushes out all traces of the currently running executable
* so that a new one can be started
*/
-
static void flush_old_files(struct files_struct * files)
{
long j = -1;
current->sas_ss_sp = current->sas_ss_size = 0;
if (current->euid == current->uid && current->egid == current->gid)
- current->mm->dumpable = 1;
+ set_dumpable(current->mm, 1);
else
- current->mm->dumpable = suid_dumpable;
+ set_dumpable(current->mm, suid_dumpable);
name = bprm->filename;
*/
current->mm->task_size = TASK_SIZE;
- if (bprm->e_uid != current->euid || bprm->e_gid != current->egid ||
- file_permission(bprm->file, MAY_READ) ||
- (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
+ if (bprm->e_uid != current->euid || bprm->e_gid != current->egid) {
suid_keys(current);
- current->mm->dumpable = suid_dumpable;
+ set_dumpable(current->mm, suid_dumpable);
+ current->pdeath_signal = 0;
+ } else if (file_permission(bprm->file, MAY_READ) ||
+ (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
+ suid_keys(current);
+ set_dumpable(current->mm, suid_dumpable);
}
/* An exec changes our domain. We are no longer part of the thread
{
int unsafe;
- if (bprm->e_uid != current->uid)
+ if (bprm->e_uid != current->uid) {
suid_keys(current);
+ current->pdeath_signal = 0;
+ }
exec_keys(current);
task_lock(current);
retval = -ENOENT;
for (try=0; try<2; try++) {
read_lock(&binfmt_lock);
- for (fmt = formats ; fmt ; fmt = fmt->next) {
+ list_for_each_entry(fmt, &formats, lh) {
int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
if (!fn)
continue;
goto out;
out_ptr += rc;
break;
+ /* core limit size */
+ case 'c':
+ rc = snprintf(out_ptr, out_end - out_ptr,
+ "%lu", current->signal->rlim[RLIMIT_CORE].rlim_cur);
+ if (rc > out_end - out_ptr)
+ goto out;
+ out_ptr += rc;
+ break;
default:
break;
}
return core_waiters;
}
+/*
+ * set_dumpable converts traditional three-value dumpable to two flags and
+ * stores them into mm->flags. It modifies lower two bits of mm->flags, but
+ * these bits are not changed atomically. So get_dumpable can observe the
+ * intermediate state. To avoid doing unexpected behavior, get get_dumpable
+ * return either old dumpable or new one by paying attention to the order of
+ * modifying the bits.
+ *
+ * dumpable | mm->flags (binary)
+ * old new | initial interim final
+ * ---------+-----------------------
+ * 0 1 | 00 01 01
+ * 0 2 | 00 10(*) 11
+ * 1 0 | 01 00 00
+ * 1 2 | 01 11 11
+ * 2 0 | 11 10(*) 00
+ * 2 1 | 11 11 01
+ *
+ * (*) get_dumpable regards interim value of 10 as 11.
+ */
+void set_dumpable(struct mm_struct *mm, int value)
+{
+ switch (value) {
+ case 0:
+ clear_bit(MMF_DUMPABLE, &mm->flags);
+ smp_wmb();
+ clear_bit(MMF_DUMP_SECURELY, &mm->flags);
+ break;
+ case 1:
+ set_bit(MMF_DUMPABLE, &mm->flags);
+ smp_wmb();
+ clear_bit(MMF_DUMP_SECURELY, &mm->flags);
+ break;
+ case 2:
+ set_bit(MMF_DUMP_SECURELY, &mm->flags);
+ smp_wmb();
+ set_bit(MMF_DUMPABLE, &mm->flags);
+ break;
+ }
+}
+EXPORT_SYMBOL_GPL(set_dumpable);
+
+int get_dumpable(struct mm_struct *mm)
+{
+ int ret;
+
+ ret = mm->flags & 0x3;
+ return (ret >= 2) ? 2 : ret;
+}
+
int do_coredump(long signr, int exit_code, struct pt_regs * regs)
{
char corename[CORENAME_MAX_SIZE + 1];
int fsuid = current->fsuid;
int flag = 0;
int ispipe = 0;
+ unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
+ char **helper_argv = NULL;
+ int helper_argc = 0;
+ char *delimit;
audit_core_dumps(signr);
if (!binfmt || !binfmt->core_dump)
goto fail;
down_write(&mm->mmap_sem);
- if (!mm->dumpable) {
+ if (!get_dumpable(mm)) {
up_write(&mm->mmap_sem);
goto fail;
}
* process nor do we know its entire history. We only know it
* was tainted so we dump it as root in mode 2.
*/
- if (mm->dumpable == 2) { /* Setuid core dump mode */
+ if (get_dumpable(mm) == 2) { /* Setuid core dump mode */
flag = O_EXCL; /* Stop rewrite attacks */
current->fsuid = 0; /* Dump root private */
}
- mm->dumpable = 0;
+ set_dumpable(mm, 0);
retval = coredump_wait(exit_code);
if (retval < 0)
*/
clear_thread_flag(TIF_SIGPENDING);
- if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump)
- goto fail_unlock;
-
/*
* lock_kernel() because format_corename() is controlled by sysctl, which
* uses lock_kernel()
lock_kernel();
ispipe = format_corename(corename, core_pattern, signr);
unlock_kernel();
+ /*
+ * Don't bother to check the RLIMIT_CORE value if core_pattern points
+ * to a pipe. Since we're not writing directly to the filesystem
+ * RLIMIT_CORE doesn't really apply, as no actual core file will be
+ * created unless the pipe reader choses to write out the core file
+ * at which point file size limits and permissions will be imposed
+ * as it does with any other process
+ */
+ if ((!ispipe) && (core_limit < binfmt->min_coredump))
+ goto fail_unlock;
+
if (ispipe) {
+ helper_argv = argv_split(GFP_KERNEL, corename+1, &helper_argc);
+ /* Terminate the string before the first option */
+ delimit = strchr(corename, ' ');
+ if (delimit)
+ *delimit = '\0';
+ delimit = strrchr(helper_argv[0], '/');
+ if (delimit)
+ delimit++;
+ else
+ delimit = helper_argv[0];
+ if (!strcmp(delimit, current->comm)) {
+ printk(KERN_NOTICE "Recursive core dump detected, "
+ "aborting\n");
+ goto fail_unlock;
+ }
+
+ core_limit = RLIM_INFINITY;
+
/* SIGPIPE can happen, but it's just never processed */
- if(call_usermodehelper_pipe(corename+1, NULL, NULL, &file)) {
+ if (call_usermodehelper_pipe(corename+1, helper_argv, NULL,
+ &file)) {
printk(KERN_INFO "Core dump to %s pipe failed\n",
corename);
goto fail_unlock;
if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0)
goto close_fail;
- retval = binfmt->core_dump(signr, regs, file);
+ retval = binfmt->core_dump(signr, regs, file, core_limit);
if (retval)
current->signal->group_exit_code |= 0x80;
close_fail:
filp_close(file, NULL);
fail_unlock:
+ if (helper_argv)
+ argv_free(helper_argv);
+
current->fsuid = fsuid;
complete_all(&mm->core_done);
fail:
projects / linux-2.6 / blobdiff