Revision 73223e4e2e3867ebf033a5a8eb2e5df0158ccc99 authored by zhong jiang on 18 August 2017, 22:16:24 UTC, committed by Linus Torvalds on 18 August 2017, 22:32:02 UTC
I hit a use after free issue when executing trinity and repoduced it
with KASAN enabled.  The related call trace is as follows.

  BUG: KASan: use after free in SyS_get_mempolicy+0x3c8/0x960 at addr ffff8801f582d766
  Read of size 2 by task syz-executor1/798

  INFO: Allocated in mpol_new.part.2+0x74/0x160 age=3 cpu=1 pid=799
     __slab_alloc+0x768/0x970
     kmem_cache_alloc+0x2e7/0x450
     mpol_new.part.2+0x74/0x160
     mpol_new+0x66/0x80
     SyS_mbind+0x267/0x9f0
     system_call_fastpath+0x16/0x1b
  INFO: Freed in __mpol_put+0x2b/0x40 age=4 cpu=1 pid=799
     __slab_free+0x495/0x8e0
     kmem_cache_free+0x2f3/0x4c0
     __mpol_put+0x2b/0x40
     SyS_mbind+0x383/0x9f0
     system_call_fastpath+0x16/0x1b
  INFO: Slab 0xffffea0009cb8dc0 objects=23 used=8 fp=0xffff8801f582de40 flags=0x200000000004080
  INFO: Object 0xffff8801f582d760 @offset=5984 fp=0xffff8801f582d600

  Bytes b4 ffff8801f582d750: ae 01 ff ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a  ........ZZZZZZZZ
  Object ffff8801f582d760: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
  Object ffff8801f582d770: 6b 6b 6b 6b 6b 6b 6b a5                          kkkkkkk.
  Redzone ffff8801f582d778: bb bb bb bb bb bb bb bb                          ........
  Padding ffff8801f582d8b8: 5a 5a 5a 5a 5a 5a 5a 5a                          ZZZZZZZZ
  Memory state around the buggy address:
  ffff8801f582d600: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffff8801f582d680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  >ffff8801f582d700: fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb fc

!shared memory policy is not protected against parallel removal by other
thread which is normally protected by the mmap_sem.  do_get_mempolicy,
however, drops the lock midway while we can still access it later.

Early premature up_read is a historical artifact from times when
put_user was called in this path see https://lwn.net/Articles/124754/
but that is gone since 8bccd85ffbaf ("[PATCH] Implement sys_* do_*
layering in the memory policy layer.").  but when we have the the
current mempolicy ref count model.  The issue was introduced
accordingly.

Fix the issue by removing the premature release.

Link: http://lkml.kernel.org/r/1502950924-27521-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>	[2.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent da094e4
Raw File
compat.c
/*
 * 32 bit compatibility code for System V IPC
 *
 * Copyright (C) 1997,1998	Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997		David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1999		Arun Sharma <arun.sharma@intel.com>
 * Copyright (C) 2000		VA Linux Co
 * Copyright (C) 2000		Don Dugger <n0ano@valinux.com>
 * Copyright (C) 2000           Hewlett-Packard Co.
 * Copyright (C) 2000           David Mosberger-Tang <davidm@hpl.hp.com>
 * Copyright (C) 2000           Gerhard Tonn (ton@de.ibm.com)
 * Copyright (C) 2000-2002      Andi Kleen, SuSE Labs (x86-64 port)
 * Copyright (C) 2000		Silicon Graphics, Inc.
 * Copyright (C) 2001		IBM
 * Copyright (C) 2004		IBM Deutschland Entwicklung GmbH, IBM Corporation
 * Copyright (C) 2004		Arnd Bergmann (arnd@arndb.de)
 *
 * This code is collected from the versions for sparc64, mips64, s390x, ia64,
 * ppc64 and x86_64, all of which are based on the original sparc64 version
 * by Jakub Jelinek.
 *
 */
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/highuid.h>
#include <linux/init.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/syscalls.h>
#include <linux/ptrace.h>

#include <linux/mutex.h>
#include <linux/uaccess.h>

#include "util.h"

struct compat_msgbuf {
	compat_long_t mtype;
	char mtext[1];
};

struct compat_ipc_perm {
	key_t key;
	__compat_uid_t uid;
	__compat_gid_t gid;
	__compat_uid_t cuid;
	__compat_gid_t cgid;
	compat_mode_t mode;
	unsigned short seq;
};

struct compat_semid_ds {
	struct compat_ipc_perm sem_perm;
	compat_time_t sem_otime;
	compat_time_t sem_ctime;
	compat_uptr_t sem_base;
	compat_uptr_t sem_pending;
	compat_uptr_t sem_pending_last;
	compat_uptr_t undo;
	unsigned short sem_nsems;
};

struct compat_msqid_ds {
	struct compat_ipc_perm msg_perm;
	compat_uptr_t msg_first;
	compat_uptr_t msg_last;
	compat_time_t msg_stime;
	compat_time_t msg_rtime;
	compat_time_t msg_ctime;
	compat_ulong_t msg_lcbytes;
	compat_ulong_t msg_lqbytes;
	unsigned short msg_cbytes;
	unsigned short msg_qnum;
	unsigned short msg_qbytes;
	compat_ipc_pid_t msg_lspid;
	compat_ipc_pid_t msg_lrpid;
};

struct compat_shmid_ds {
	struct compat_ipc_perm shm_perm;
	int shm_segsz;
	compat_time_t shm_atime;
	compat_time_t shm_dtime;
	compat_time_t shm_ctime;
	compat_ipc_pid_t shm_cpid;
	compat_ipc_pid_t shm_lpid;
	unsigned short shm_nattch;
	unsigned short shm_unused;
	compat_uptr_t shm_unused2;
	compat_uptr_t shm_unused3;
};

struct compat_ipc_kludge {
	compat_uptr_t msgp;
	compat_long_t msgtyp;
};

struct compat_shminfo64 {
	compat_ulong_t shmmax;
	compat_ulong_t shmmin;
	compat_ulong_t shmmni;
	compat_ulong_t shmseg;
	compat_ulong_t shmall;
	compat_ulong_t __unused1;
	compat_ulong_t __unused2;
	compat_ulong_t __unused3;
	compat_ulong_t __unused4;
};

struct compat_shm_info {
	compat_int_t used_ids;
	compat_ulong_t shm_tot, shm_rss, shm_swp;
	compat_ulong_t swap_attempts, swap_successes;
};

static inline int compat_ipc_parse_version(int *cmd)
{
#ifdef	CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
	int version = *cmd & IPC_64;

	/* this is tricky: architectures that have support for the old
	 * ipc structures in 64 bit binaries need to have IPC_64 set
	 * in cmd, the others need to have it cleared */
#ifndef ipc_parse_version
	*cmd |= IPC_64;
#else
	*cmd &= ~IPC_64;
#endif
	return version;
#else
	/* With the asm-generic APIs, we always use the 64-bit versions. */
	return IPC_64;
#endif
}

static inline int __get_compat_ipc64_perm(struct ipc64_perm *p64,
					  struct compat_ipc64_perm __user *up64)
{
	int err;

	err  = __get_user(p64->uid, &up64->uid);
	err |= __get_user(p64->gid, &up64->gid);
	err |= __get_user(p64->mode, &up64->mode);
	return err;
}

static inline int __get_compat_ipc_perm(struct ipc64_perm *p,
					struct compat_ipc_perm __user *up)
{
	int err;

	err  = __get_user(p->uid, &up->uid);
	err |= __get_user(p->gid, &up->gid);
	err |= __get_user(p->mode, &up->mode);
	return err;
}

static inline int __put_compat_ipc64_perm(struct ipc64_perm *p64,
					  struct compat_ipc64_perm __user *up64)
{
	int err;

	err  = __put_user(p64->key, &up64->key);
	err |= __put_user(p64->uid, &up64->uid);
	err |= __put_user(p64->gid, &up64->gid);
	err |= __put_user(p64->cuid, &up64->cuid);
	err |= __put_user(p64->cgid, &up64->cgid);
	err |= __put_user(p64->mode, &up64->mode);
	err |= __put_user(p64->seq, &up64->seq);
	return err;
}

static inline int __put_compat_ipc_perm(struct ipc64_perm *p,
					struct compat_ipc_perm __user *uip)
{
	int err;
	__compat_uid_t u;
	__compat_gid_t g;

	err  = __put_user(p->key, &uip->key);
	SET_UID(u, p->uid);
	err |= __put_user(u, &uip->uid);
	SET_GID(g, p->gid);
	err |= __put_user(g, &uip->gid);
	SET_UID(u, p->cuid);
	err |= __put_user(u, &uip->cuid);
	SET_GID(g, p->cgid);
	err |= __put_user(g, &uip->cgid);
	err |= __put_user(p->mode, &uip->mode);
	err |= __put_user(p->seq, &uip->seq);
	return err;
}

static inline int get_compat_semid64_ds(struct semid64_ds *sem64,
					struct compat_semid64_ds __user *up64)
{
	if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
		return -EFAULT;
	return __get_compat_ipc64_perm(&sem64->sem_perm, &up64->sem_perm);
}

static inline int get_compat_semid_ds(struct semid64_ds *s,
				      struct compat_semid_ds __user *up)
{
	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
		return -EFAULT;
	return __get_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
}

static inline int put_compat_semid64_ds(struct semid64_ds *sem64,
					struct compat_semid64_ds __user *up64)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
		return -EFAULT;
	err  = __put_compat_ipc64_perm(&sem64->sem_perm, &up64->sem_perm);
	err |= __put_user(sem64->sem_otime, &up64->sem_otime);
	err |= __put_user(sem64->sem_ctime, &up64->sem_ctime);
	err |= __put_user(sem64->sem_nsems, &up64->sem_nsems);
	return err;
}

static inline int put_compat_semid_ds(struct semid64_ds *s,
				      struct compat_semid_ds __user *up)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
		return -EFAULT;
	err  = __put_compat_ipc_perm(&s->sem_perm, &up->sem_perm);
	err |= __put_user(s->sem_otime, &up->sem_otime);
	err |= __put_user(s->sem_ctime, &up->sem_ctime);
	err |= __put_user(s->sem_nsems, &up->sem_nsems);
	return err;
}

static long do_compat_semctl(int first, int second, int third, u32 pad)
{
	unsigned long fourth;
	int err, err2;
	struct semid64_ds sem64;
	struct semid64_ds __user *up64;
	int version = compat_ipc_parse_version(&third);

	memset(&sem64, 0, sizeof(sem64));

	if ((third & (~IPC_64)) == SETVAL)
#ifdef __BIG_ENDIAN
		fourth = (unsigned long)pad << 32;
#else
		fourth = pad;
#endif
	else
		fourth = (unsigned long)compat_ptr(pad);
	switch (third & (~IPC_64)) {
	case IPC_INFO:
	case IPC_RMID:
	case SEM_INFO:
	case GETVAL:
	case GETPID:
	case GETNCNT:
	case GETZCNT:
	case GETALL:
	case SETVAL:
	case SETALL:
		err = sys_semctl(first, second, third, fourth);
		break;

	case IPC_STAT:
	case SEM_STAT:
		up64 = compat_alloc_user_space(sizeof(sem64));
		fourth = (unsigned long)up64;
		err = sys_semctl(first, second, third, fourth);
		if (err < 0)
			break;
		if (copy_from_user(&sem64, up64, sizeof(sem64)))
			err2 = -EFAULT;
		else if (version == IPC_64)
			err2 = put_compat_semid64_ds(&sem64, compat_ptr(pad));
		else
			err2 = put_compat_semid_ds(&sem64, compat_ptr(pad));
		if (err2)
			err = -EFAULT;
		break;

	case IPC_SET:
		if (version == IPC_64)
			err = get_compat_semid64_ds(&sem64, compat_ptr(pad));
		else
			err = get_compat_semid_ds(&sem64, compat_ptr(pad));

		up64 = compat_alloc_user_space(sizeof(sem64));
		if (copy_to_user(up64, &sem64, sizeof(sem64)))
			err = -EFAULT;
		if (err)
			break;

		fourth = (unsigned long)up64;
		err = sys_semctl(first, second, third, fourth);
		break;

	default:
		err = -EINVAL;
		break;
	}
	return err;
}

static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
{
	struct compat_msgbuf __user *msgp = dest;
	size_t msgsz;

	if (put_user(msg->m_type, &msgp->mtype))
		return -EFAULT;

	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
	if (store_msg(msgp->mtext, msg, msgsz))
		return -EFAULT;
	return msgsz;
}

#ifndef COMPAT_SHMLBA
#define COMPAT_SHMLBA	SHMLBA
#endif

#ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
	u32, third, compat_uptr_t, ptr, u32, fifth)
{
	int version;
	u32 pad;

	version = call >> 16; /* hack for backward compatibility */
	call &= 0xffff;

	switch (call) {
	case SEMOP:
		/* struct sembuf is the same on 32 and 64bit :)) */
		return sys_semtimedop(first, compat_ptr(ptr), second, NULL);
	case SEMTIMEDOP:
		return compat_sys_semtimedop(first, compat_ptr(ptr), second,
						compat_ptr(fifth));
	case SEMGET:
		return sys_semget(first, second, third);
	case SEMCTL:
		if (!ptr)
			return -EINVAL;
		if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
			return -EFAULT;
		return do_compat_semctl(first, second, third, pad);

	case MSGSND: {
		struct compat_msgbuf __user *up = compat_ptr(ptr);
		compat_long_t type;

		if (first < 0 || second < 0)
			return -EINVAL;

		if (get_user(type, &up->mtype))
			return -EFAULT;

		return do_msgsnd(first, type, up->mtext, second, third);
	}
	case MSGRCV: {
		void __user *uptr = compat_ptr(ptr);

		if (first < 0 || second < 0)
			return -EINVAL;

		if (!version) {
			struct compat_ipc_kludge ipck;
			if (!uptr)
				return -EINVAL;
			if (copy_from_user(&ipck, uptr, sizeof(ipck)))
				return -EFAULT;
			uptr = compat_ptr(ipck.msgp);
			fifth = ipck.msgtyp;
		}
		return do_msgrcv(first, uptr, second, (s32)fifth, third,
				 compat_do_msg_fill);
	}
	case MSGGET:
		return sys_msgget(first, second);
	case MSGCTL:
		return compat_sys_msgctl(first, second, compat_ptr(ptr));

	case SHMAT: {
		int err;
		unsigned long raddr;

		if (version == 1)
			return -EINVAL;
		err = do_shmat(first, compat_ptr(ptr), second, &raddr,
			       COMPAT_SHMLBA);
		if (err < 0)
			return err;
		return put_user(raddr, (compat_ulong_t *)compat_ptr(third));
	}
	case SHMDT:
		return sys_shmdt(compat_ptr(ptr));
	case SHMGET:
		return sys_shmget(first, (unsigned)second, third);
	case SHMCTL:
		return compat_sys_shmctl(first, second, compat_ptr(ptr));
	}

	return -ENOSYS;
}
#endif

COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
{
	return do_compat_semctl(semid, semnum, cmd, arg);
}

COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
		       compat_ssize_t, msgsz, int, msgflg)
{
	struct compat_msgbuf __user *up = compat_ptr(msgp);
	compat_long_t mtype;

	if (get_user(mtype, &up->mtype))
		return -EFAULT;
	return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
}

COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp,
		       compat_ssize_t, msgsz, compat_long_t, msgtyp, int, msgflg)
{
	return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp,
			 msgflg, compat_do_msg_fill);
}

static inline int get_compat_msqid64(struct msqid64_ds *m64,
				     struct compat_msqid64_ds __user *up64)
{
	int err;

	if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
		return -EFAULT;
	err  = __get_compat_ipc64_perm(&m64->msg_perm, &up64->msg_perm);
	err |= __get_user(m64->msg_qbytes, &up64->msg_qbytes);
	return err;
}

static inline int get_compat_msqid(struct msqid64_ds *m,
				   struct compat_msqid_ds __user *up)
{
	int err;

	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
		return -EFAULT;
	err  = __get_compat_ipc_perm(&m->msg_perm, &up->msg_perm);
	err |= __get_user(m->msg_qbytes, &up->msg_qbytes);
	return err;
}

static inline int put_compat_msqid64_ds(struct msqid64_ds *m64,
				 struct compat_msqid64_ds __user *up64)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
		return -EFAULT;
	err  = __put_compat_ipc64_perm(&m64->msg_perm, &up64->msg_perm);
	err |= __put_user(m64->msg_stime, &up64->msg_stime);
	err |= __put_user(m64->msg_rtime, &up64->msg_rtime);
	err |= __put_user(m64->msg_ctime, &up64->msg_ctime);
	err |= __put_user(m64->msg_cbytes, &up64->msg_cbytes);
	err |= __put_user(m64->msg_qnum, &up64->msg_qnum);
	err |= __put_user(m64->msg_qbytes, &up64->msg_qbytes);
	err |= __put_user(m64->msg_lspid, &up64->msg_lspid);
	err |= __put_user(m64->msg_lrpid, &up64->msg_lrpid);
	return err;
}

static inline int put_compat_msqid_ds(struct msqid64_ds *m,
				      struct compat_msqid_ds __user *up)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
		return -EFAULT;
	err  = __put_compat_ipc_perm(&m->msg_perm, &up->msg_perm);
	err |= __put_user(m->msg_stime, &up->msg_stime);
	err |= __put_user(m->msg_rtime, &up->msg_rtime);
	err |= __put_user(m->msg_ctime, &up->msg_ctime);
	err |= __put_user(m->msg_cbytes, &up->msg_cbytes);
	err |= __put_user(m->msg_qnum, &up->msg_qnum);
	err |= __put_user(m->msg_qbytes, &up->msg_qbytes);
	err |= __put_user(m->msg_lspid, &up->msg_lspid);
	err |= __put_user(m->msg_lrpid, &up->msg_lrpid);
	return err;
}

COMPAT_SYSCALL_DEFINE3(msgctl, int, first, int, second, void __user *, uptr)
{
	int err, err2;
	struct msqid64_ds m64;
	int version = compat_ipc_parse_version(&second);
	void __user *p;

	memset(&m64, 0, sizeof(m64));

	switch (second & (~IPC_64)) {
	case IPC_INFO:
	case IPC_RMID:
	case MSG_INFO:
		err = sys_msgctl(first, second, uptr);
		break;

	case IPC_SET:
		if (version == IPC_64)
			err = get_compat_msqid64(&m64, uptr);
		else
			err = get_compat_msqid(&m64, uptr);

		if (err)
			break;
		p = compat_alloc_user_space(sizeof(m64));
		if (copy_to_user(p, &m64, sizeof(m64)))
			err = -EFAULT;
		else
			err = sys_msgctl(first, second, p);
		break;

	case IPC_STAT:
	case MSG_STAT:
		p = compat_alloc_user_space(sizeof(m64));
		err = sys_msgctl(first, second, p);
		if (err < 0)
			break;
		if (copy_from_user(&m64, p, sizeof(m64)))
			err2 = -EFAULT;
		else if (version == IPC_64)
			err2 = put_compat_msqid64_ds(&m64, uptr);
		else
			err2 = put_compat_msqid_ds(&m64, uptr);
		if (err2)
			err = -EFAULT;
		break;

	default:
		err = -EINVAL;
		break;
	}
	return err;
}

COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg)
{
	unsigned long ret;
	long err;

	err = do_shmat(shmid, compat_ptr(shmaddr), shmflg, &ret, COMPAT_SHMLBA);
	if (err)
		return err;
	force_successful_syscall_return();
	return (long)ret;
}

static inline int get_compat_shmid64_ds(struct shmid64_ds *sem64,
					struct compat_shmid64_ds __user *up64)
{
	if (!access_ok(VERIFY_READ, up64, sizeof(*up64)))
		return -EFAULT;
	return __get_compat_ipc64_perm(&sem64->shm_perm, &up64->shm_perm);
}

static inline int get_compat_shmid_ds(struct shmid64_ds *s,
				      struct compat_shmid_ds __user *up)
{
	if (!access_ok(VERIFY_READ, up, sizeof(*up)))
		return -EFAULT;
	return __get_compat_ipc_perm(&s->shm_perm, &up->shm_perm);
}

static inline int put_compat_shmid64_ds(struct shmid64_ds *sem64,
					struct compat_shmid64_ds __user *up64)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
		return -EFAULT;
	err  = __put_compat_ipc64_perm(&sem64->shm_perm, &up64->shm_perm);
	err |= __put_user(sem64->shm_atime, &up64->shm_atime);
	err |= __put_user(sem64->shm_dtime, &up64->shm_dtime);
	err |= __put_user(sem64->shm_ctime, &up64->shm_ctime);
	err |= __put_user(sem64->shm_segsz, &up64->shm_segsz);
	err |= __put_user(sem64->shm_nattch, &up64->shm_nattch);
	err |= __put_user(sem64->shm_cpid, &up64->shm_cpid);
	err |= __put_user(sem64->shm_lpid, &up64->shm_lpid);
	return err;
}

static inline int put_compat_shmid_ds(struct shmid64_ds *s,
				      struct compat_shmid_ds __user *up)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
		return -EFAULT;
	err  = __put_compat_ipc_perm(&s->shm_perm, &up->shm_perm);
	err |= __put_user(s->shm_atime, &up->shm_atime);
	err |= __put_user(s->shm_dtime, &up->shm_dtime);
	err |= __put_user(s->shm_ctime, &up->shm_ctime);
	err |= __put_user(s->shm_segsz, &up->shm_segsz);
	err |= __put_user(s->shm_nattch, &up->shm_nattch);
	err |= __put_user(s->shm_cpid, &up->shm_cpid);
	err |= __put_user(s->shm_lpid, &up->shm_lpid);
	return err;
}

static inline int put_compat_shminfo64(struct shminfo64 *smi,
				       struct compat_shminfo64 __user *up64)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up64, sizeof(*up64)))
		return -EFAULT;
	if (smi->shmmax > INT_MAX)
		smi->shmmax = INT_MAX;
	err  = __put_user(smi->shmmax, &up64->shmmax);
	err |= __put_user(smi->shmmin, &up64->shmmin);
	err |= __put_user(smi->shmmni, &up64->shmmni);
	err |= __put_user(smi->shmseg, &up64->shmseg);
	err |= __put_user(smi->shmall, &up64->shmall);
	return err;
}

static inline int put_compat_shminfo(struct shminfo64 *smi,
				     struct shminfo __user *up)
{
	int err;

	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)))
		return -EFAULT;
	if (smi->shmmax > INT_MAX)
		smi->shmmax = INT_MAX;
	err  = __put_user(smi->shmmax, &up->shmmax);
	err |= __put_user(smi->shmmin, &up->shmmin);
	err |= __put_user(smi->shmmni, &up->shmmni);
	err |= __put_user(smi->shmseg, &up->shmseg);
	err |= __put_user(smi->shmall, &up->shmall);
	return err;
}

static inline int put_compat_shm_info(struct shm_info __user *ip,
				      struct compat_shm_info __user *uip)
{
	int err;
	struct shm_info si;

	if (!access_ok(VERIFY_WRITE, uip, sizeof(*uip)) ||
	    copy_from_user(&si, ip, sizeof(si)))
		return -EFAULT;
	err  = __put_user(si.used_ids, &uip->used_ids);
	err |= __put_user(si.shm_tot, &uip->shm_tot);
	err |= __put_user(si.shm_rss, &uip->shm_rss);
	err |= __put_user(si.shm_swp, &uip->shm_swp);
	err |= __put_user(si.swap_attempts, &uip->swap_attempts);
	err |= __put_user(si.swap_successes, &uip->swap_successes);
	return err;
}

COMPAT_SYSCALL_DEFINE3(shmctl, int, first, int, second, void __user *, uptr)
{
	void __user *p;
	struct shmid64_ds sem64;
	struct shminfo64 smi;
	int err, err2;
	int version = compat_ipc_parse_version(&second);

	memset(&sem64, 0, sizeof(sem64));

	switch (second & (~IPC_64)) {
	case IPC_RMID:
	case SHM_LOCK:
	case SHM_UNLOCK:
		err = sys_shmctl(first, second, uptr);
		break;

	case IPC_INFO:
		p = compat_alloc_user_space(sizeof(smi));
		err = sys_shmctl(first, second, p);
		if (err < 0)
			break;
		if (copy_from_user(&smi, p, sizeof(smi)))
			err2 = -EFAULT;
		else if (version == IPC_64)
			err2 = put_compat_shminfo64(&smi, uptr);
		else
			err2 = put_compat_shminfo(&smi, uptr);
		if (err2)
			err = -EFAULT;
		break;


	case IPC_SET:
		if (version == IPC_64)
			err = get_compat_shmid64_ds(&sem64, uptr);
		else
			err = get_compat_shmid_ds(&sem64, uptr);

		if (err)
			break;
		p = compat_alloc_user_space(sizeof(sem64));
		if (copy_to_user(p, &sem64, sizeof(sem64)))
			err = -EFAULT;
		else
			err = sys_shmctl(first, second, p);
		break;

	case IPC_STAT:
	case SHM_STAT:
		p = compat_alloc_user_space(sizeof(sem64));
		err = sys_shmctl(first, second, p);
		if (err < 0)
			break;
		if (copy_from_user(&sem64, p, sizeof(sem64)))
			err2 = -EFAULT;
		else if (version == IPC_64)
			err2 = put_compat_shmid64_ds(&sem64, uptr);
		else
			err2 = put_compat_shmid_ds(&sem64, uptr);
		if (err2)
			err = -EFAULT;
		break;

	case SHM_INFO:
		p = compat_alloc_user_space(sizeof(struct shm_info));
		err = sys_shmctl(first, second, p);
		if (err < 0)
			break;
		err2 = put_compat_shm_info(p, uptr);
		if (err2)
			err = -EFAULT;
		break;

	default:
		err = -EINVAL;
		break;
	}
	return err;
}

COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
		       unsigned, nsops,
		       const struct compat_timespec __user *, timeout)
{
	struct timespec __user *ts64;
	if (compat_convert_timespec(&ts64, timeout))
		return -EFAULT;
	return sys_semtimedop(semid, tsems, nsops, ts64);
}
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