mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-20 14:16:02 +00:00
![Elena Reshetova](/assets/img/avatar_default.png)
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Link: http://lkml.kernel.org/r/1499417992-3238-2-git-send-email-elena.reshetova@intel.com Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: <arozansk@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
182 lines
3.6 KiB
C
182 lines
3.6 KiB
C
/*
|
|
* linux/ipc/msgutil.c
|
|
* Copyright (C) 1999, 2004 Manfred Spraul
|
|
*
|
|
* This file is released under GNU General Public Licence version 2 or
|
|
* (at your option) any later version.
|
|
*
|
|
* See the file COPYING for more details.
|
|
*/
|
|
|
|
#include <linux/spinlock.h>
|
|
#include <linux/init.h>
|
|
#include <linux/security.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/ipc.h>
|
|
#include <linux/msg.h>
|
|
#include <linux/ipc_namespace.h>
|
|
#include <linux/utsname.h>
|
|
#include <linux/proc_ns.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include "util.h"
|
|
|
|
DEFINE_SPINLOCK(mq_lock);
|
|
|
|
/*
|
|
* The next 2 defines are here bc this is the only file
|
|
* compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
|
|
* and not CONFIG_IPC_NS.
|
|
*/
|
|
struct ipc_namespace init_ipc_ns = {
|
|
.count = REFCOUNT_INIT(1),
|
|
.user_ns = &init_user_ns,
|
|
.ns.inum = PROC_IPC_INIT_INO,
|
|
#ifdef CONFIG_IPC_NS
|
|
.ns.ops = &ipcns_operations,
|
|
#endif
|
|
};
|
|
|
|
struct msg_msgseg {
|
|
struct msg_msgseg *next;
|
|
/* the next part of the message follows immediately */
|
|
};
|
|
|
|
#define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg))
|
|
#define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
|
|
|
|
|
|
static struct msg_msg *alloc_msg(size_t len)
|
|
{
|
|
struct msg_msg *msg;
|
|
struct msg_msgseg **pseg;
|
|
size_t alen;
|
|
|
|
alen = min(len, DATALEN_MSG);
|
|
msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL_ACCOUNT);
|
|
if (msg == NULL)
|
|
return NULL;
|
|
|
|
msg->next = NULL;
|
|
msg->security = NULL;
|
|
|
|
len -= alen;
|
|
pseg = &msg->next;
|
|
while (len > 0) {
|
|
struct msg_msgseg *seg;
|
|
alen = min(len, DATALEN_SEG);
|
|
seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL_ACCOUNT);
|
|
if (seg == NULL)
|
|
goto out_err;
|
|
*pseg = seg;
|
|
seg->next = NULL;
|
|
pseg = &seg->next;
|
|
len -= alen;
|
|
}
|
|
|
|
return msg;
|
|
|
|
out_err:
|
|
free_msg(msg);
|
|
return NULL;
|
|
}
|
|
|
|
struct msg_msg *load_msg(const void __user *src, size_t len)
|
|
{
|
|
struct msg_msg *msg;
|
|
struct msg_msgseg *seg;
|
|
int err = -EFAULT;
|
|
size_t alen;
|
|
|
|
msg = alloc_msg(len);
|
|
if (msg == NULL)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
alen = min(len, DATALEN_MSG);
|
|
if (copy_from_user(msg + 1, src, alen))
|
|
goto out_err;
|
|
|
|
for (seg = msg->next; seg != NULL; seg = seg->next) {
|
|
len -= alen;
|
|
src = (char __user *)src + alen;
|
|
alen = min(len, DATALEN_SEG);
|
|
if (copy_from_user(seg + 1, src, alen))
|
|
goto out_err;
|
|
}
|
|
|
|
err = security_msg_msg_alloc(msg);
|
|
if (err)
|
|
goto out_err;
|
|
|
|
return msg;
|
|
|
|
out_err:
|
|
free_msg(msg);
|
|
return ERR_PTR(err);
|
|
}
|
|
#ifdef CONFIG_CHECKPOINT_RESTORE
|
|
struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
|
|
{
|
|
struct msg_msgseg *dst_pseg, *src_pseg;
|
|
size_t len = src->m_ts;
|
|
size_t alen;
|
|
|
|
if (src->m_ts > dst->m_ts)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
alen = min(len, DATALEN_MSG);
|
|
memcpy(dst + 1, src + 1, alen);
|
|
|
|
for (dst_pseg = dst->next, src_pseg = src->next;
|
|
src_pseg != NULL;
|
|
dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
|
|
|
|
len -= alen;
|
|
alen = min(len, DATALEN_SEG);
|
|
memcpy(dst_pseg + 1, src_pseg + 1, alen);
|
|
}
|
|
|
|
dst->m_type = src->m_type;
|
|
dst->m_ts = src->m_ts;
|
|
|
|
return dst;
|
|
}
|
|
#else
|
|
struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
|
|
{
|
|
return ERR_PTR(-ENOSYS);
|
|
}
|
|
#endif
|
|
int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
|
|
{
|
|
size_t alen;
|
|
struct msg_msgseg *seg;
|
|
|
|
alen = min(len, DATALEN_MSG);
|
|
if (copy_to_user(dest, msg + 1, alen))
|
|
return -1;
|
|
|
|
for (seg = msg->next; seg != NULL; seg = seg->next) {
|
|
len -= alen;
|
|
dest = (char __user *)dest + alen;
|
|
alen = min(len, DATALEN_SEG);
|
|
if (copy_to_user(dest, seg + 1, alen))
|
|
return -1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void free_msg(struct msg_msg *msg)
|
|
{
|
|
struct msg_msgseg *seg;
|
|
|
|
security_msg_msg_free(msg);
|
|
|
|
seg = msg->next;
|
|
kfree(msg);
|
|
while (seg != NULL) {
|
|
struct msg_msgseg *tmp = seg->next;
|
|
kfree(seg);
|
|
seg = tmp;
|
|
}
|
|
}
|