db-d2/primevul-codebert-embeddings huggingface dataset:
Commit message: Fix length of buffer copied in __nfs4_get_acl_uncached

_copy_from_pages() used to copy data from the temporary buffer to the
user passed buffer is passed the wrong size parameter when copying
data. res.acl_len contains both the bitmap and acl lenghts while
acl_len contains the acl length after adjusting for the bitmap size.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
CVE: CVE-2012-2375
CWE: CWE-189
Vulnerability description: The __nfs4_get_acl_uncached function in fs/nfs/nfs4proc.c in the NFSv4 implementation in the Linux kernel before 3.3.2 uses an incorrect length variable during a copy operation, which allows remote NFS servers to cause a denial of service (OOPS) by sending an excessive number of bitmap words in an FATTR4_ACL reply.  NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-4131.

Project: linux
File: nfs4proc.c

static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen)
{
	struct page *pages[NFS4ACL_MAXPAGES] = {NULL, };
	struct nfs_getaclargs args = {
		.fh = NFS_FH(inode),
		.acl_pages = pages,
		.acl_len = buflen,
	};
	struct nfs_getaclres res = {
		.acl_len = buflen,
	};
	void *resp_buf;
	struct rpc_message msg = {
		.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_GETACL],
		.rpc_argp = &args,
		.rpc_resp = &res,
	};
	int ret = -ENOMEM, npages, i, acl_len = 0;

	npages = (buflen + PAGE_SIZE - 1) >> PAGE_SHIFT;
	/* As long as we're doing a round trip to the server anyway,
	 * let's be prepared for a page of acl data. */
	if (npages == 0)
		npages = 1;

	for (i = 0; i < npages; i++) {
		pages[i] = alloc_page(GFP_KERNEL);
		if (!pages[i])
			goto out_free;
	}
	if (npages > 1) {
		/* for decoding across pages */
		res.acl_scratch = alloc_page(GFP_KERNEL);
		if (!res.acl_scratch)
			goto out_free;
	}
	args.acl_len = npages * PAGE_SIZE;
	args.acl_pgbase = 0;
	/* Let decode_getfacl know not to fail if the ACL data is larger than
	 * the page we send as a guess */
	if (buf == NULL)
		res.acl_flags |= NFS4_ACL_LEN_REQUEST;
	resp_buf = page_address(pages[0]);

	dprintk("%s  buf %p buflen %zu npages %d args.acl_len %zu\n",
		__func__, buf, buflen, npages, args.acl_len);
	ret = nfs4_call_sync(NFS_SERVER(inode)->client, NFS_SERVER(inode),
			     &msg, &args.seq_args, &res.seq_res, 0);
	if (ret)
		goto out_free;

	acl_len = res.acl_len - res.acl_data_offset;
	if (acl_len > args.acl_len)
		nfs4_write_cached_acl(inode, NULL, acl_len);
	else
		nfs4_write_cached_acl(inode, resp_buf + res.acl_data_offset,
				      acl_len);
	if (buf) {
		ret = -ERANGE;
 		if (acl_len > buflen)
 			goto out_free;
 		_copy_from_pages(buf, pages, res.acl_data_offset,
				res.acl_len);
 	}
 	ret = acl_len;
 out_free:
	for (i = 0; i < npages; i++)
		if (pages[i])
			__free_page(pages[i]);
	if (res.acl_scratch)
		__free_page(res.acl_scratch);
	return ret;
}
Commit message: dl2k: Clean up rio_ioctl

The dl2k driver's rio_ioctl call has a few issues:
- No permissions checking
- Implements SIOCGMIIREG and SIOCGMIIREG using the SIOCDEVPRIVATE numbers
- Has a few ioctls that may have been used for debugging at one point
  but have no place in the kernel proper.

This patch removes all but the MII ioctls, renumbers them to use the
standard ones, and adds the proper permission check for SIOCSMIIREG.

We can also get rid of the dl2k-specific struct mii_data in favor of
the generic struct mii_ioctl_data.

Since we have the phyid on hand, we can add the SIOCGMIIPHY ioctl too.

Most of the MII code for the driver could probably be converted to use
the generic MII library but I don't have a device to test the results.

Reported-by: Stephan Mueller <stephan.mueller@atsec.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
CVE: CVE-2012-2313
CWE: CWE-264
Vulnerability description: The rio_ioctl function in drivers/net/ethernet/dlink/dl2k.c in the Linux kernel before 3.3.7 does not restrict access to the SIOCSMIIREG command, which allows local users to write data to an Ethernet adapter via an ioctl call.

Project: linux
File: dl2k.c

rio_ioctl (struct net_device *dev, struct ifreq *rq, int cmd)
 {
 	int phy_addr;
 	struct netdev_private *np = netdev_priv(dev);
	struct mii_data *miidata = (struct mii_data *) &rq->ifr_ifru;
	struct netdev_desc *desc;
	int i;
 
 	phy_addr = np->phy_addr;
 	switch (cmd) {
	case SIOCDEVPRIVATE:
		break;
	case SIOCDEVPRIVATE + 1:
		miidata->out_value = mii_read (dev, phy_addr, miidata->reg_num);
 		break;
	case SIOCDEVPRIVATE + 2:
		mii_write (dev, phy_addr, miidata->reg_num, miidata->in_value);
 		break;
	case SIOCDEVPRIVATE + 3:
		break;
	case SIOCDEVPRIVATE + 4:
		break;
	case SIOCDEVPRIVATE + 5:
		netif_stop_queue (dev);
 		break;
	case SIOCDEVPRIVATE + 6:
		netif_wake_queue (dev);
		break;
	case SIOCDEVPRIVATE + 7:
		printk
		    ("tx_full=%x cur_tx=%lx old_tx=%lx cur_rx=%lx old_rx=%lx\n",
		     netif_queue_stopped(dev), np->cur_tx, np->old_tx, np->cur_rx,
		     np->old_rx);
		break;
	case SIOCDEVPRIVATE + 8:
		printk("TX ring:\n");
		for (i = 0; i < TX_RING_SIZE; i++) {
			desc = &np->tx_ring[i];
			printk
			    ("%02x:cur:%08x next:%08x status:%08x frag1:%08x frag0:%08x",
			     i,
			     (u32) (np->tx_ring_dma + i * sizeof (*desc)),
			     (u32)le64_to_cpu(desc->next_desc),
			     (u32)le64_to_cpu(desc->status),
			     (u32)(le64_to_cpu(desc->fraginfo) >> 32),
			     (u32)le64_to_cpu(desc->fraginfo));
			printk ("\n");
		}
		printk ("\n");
		break;
 	default:
 		return -EOPNOTSUPP;
 	}
	return 0;
}
Commit message: net: sock: validate data_len before allocating skb in sock_alloc_send_pskb()

We need to validate the number of pages consumed by data_len, otherwise frags
array could be overflowed by userspace. So this patch validate data_len and
return -EMSGSIZE when data_len may occupies more frags than MAX_SKB_FRAGS.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
CVE: CVE-2012-2136
CWE: CWE-20
Vulnerability description: The sock_alloc_send_pskb function in net/core/sock.c in the Linux kernel before 3.4.5 does not properly validate a certain length value, which allows local users to cause a denial of service (heap-based buffer overflow and system crash) or possibly gain privileges by leveraging access to a TUN/TAP device.

Project: linux
File: sock.c

struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
				     unsigned long data_len, int noblock,
				     int *errcode)
{
	struct sk_buff *skb;
 	gfp_t gfp_mask;
 	long timeo;
 	int err;
 
 	gfp_mask = sk->sk_allocation;
 	if (gfp_mask & __GFP_WAIT)
		gfp_mask |= __GFP_REPEAT;

	timeo = sock_sndtimeo(sk, noblock);
	while (1) {
		err = sock_error(sk);
		if (err != 0)
			goto failure;

		err = -EPIPE;
		if (sk->sk_shutdown & SEND_SHUTDOWN)
			goto failure;

 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
 			skb = alloc_skb(header_len, gfp_mask);
 			if (skb) {
				int npages;
 				int i;
 
 				/* No pages, we're done... */
 				if (!data_len)
 					break;
 
				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 				skb->truesize += data_len;
 				skb_shinfo(skb)->nr_frags = npages;
 				for (i = 0; i < npages; i++) {
					struct page *page;

					page = alloc_pages(sk->sk_allocation, 0);
					if (!page) {
						err = -ENOBUFS;
						skb_shinfo(skb)->nr_frags = i;
						kfree_skb(skb);
						goto failure;
					}

					__skb_fill_page_desc(skb, i,
							page, 0,
							(data_len >= PAGE_SIZE ?
							 PAGE_SIZE :
							 data_len));
					data_len -= PAGE_SIZE;
				}

				/* Full success... */
				break;
			}
			err = -ENOBUFS;
			goto failure;
		}
		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
		err = -EAGAIN;
		if (!timeo)
			goto failure;
		if (signal_pending(current))
			goto interrupted;
		timeo = sock_wait_for_wmem(sk, timeo);
	}

	skb_set_owner_w(skb, sk);
	return skb;

interrupted:
	err = sock_intr_errno(timeo);
failure:
	*errcode = err;
	return NULL;
}
Commit message: [IPV6]: Fix slab corruption running ip6sic

From: Eric Sesterhenn <snakebyte@gmx.de>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
CVE: CVE-2012-1583
CWE: CWE-399
Vulnerability description: Double free vulnerability in the xfrm6_tunnel_rcv function in net/ipv6/xfrm6_tunnel.c in the Linux kernel before 2.6.22, when the xfrm6_tunnel module is enabled, allows remote attackers to cause a denial of service (panic) via crafted IPv6 packets.

Project: linux
File: xfrm6_tunnel.c

static int xfrm6_tunnel_rcv(struct sk_buff *skb)
{
	struct ipv6hdr *iph = ipv6_hdr(skb);
 	__be32 spi;
 
 	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr);
	return xfrm6_rcv_spi(skb, spi);
 }
Commit message: regset: Prevent null pointer reference on readonly regsets

The regset common infrastructure assumed that regsets would always
have .get and .set methods, but not necessarily .active methods.
Unfortunately people have since written regsets without .set methods.

Rather than putting in stub functions everywhere, handle regsets with
null .get or .set methods explicitly.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@hack.frob.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CVE: CVE-2012-1097
CWE: CWE-476
Vulnerability description: The regset (aka register set) feature in the Linux kernel before 3.2.10 does not properly handle the absence of .get and .set methods, which allows local users to cause a denial of service (NULL pointer dereference) or possibly have unspecified other impact via a (1) PTRACE_GETREGSET or (2) PTRACE_SETREGSET ptrace call.

Project: linux
File: binfmt_elf.c

static int fill_thread_core_info(struct elf_thread_core_info *t,
				 const struct user_regset_view *view,
				 long signr, size_t *total)
{
	unsigned int i;

	/*
	 * NT_PRSTATUS is the one special case, because the regset data
	 * goes into the pr_reg field inside the note contents, rather
	 * than being the whole note contents.  We fill the reset in here.
	 * We assume that regset 0 is NT_PRSTATUS.
	 */
	fill_prstatus(&t->prstatus, t->task, signr);
	(void) view->regsets[0].get(t->task, &view->regsets[0],
				    0, sizeof(t->prstatus.pr_reg),
				    &t->prstatus.pr_reg, NULL);

	fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
		  sizeof(t->prstatus), &t->prstatus);
	*total += notesize(&t->notes[0]);

	do_thread_regset_writeback(t->task, &view->regsets[0]);

	/*
	 * Each other regset might generate a note too.  For each regset
	 * that has no core_note_type or is inactive, we leave t->notes[i]
	 * all zero and we'll know to skip writing it later.
	 */
 	for (i = 1; i < view->n; ++i) {
 		const struct user_regset *regset = &view->regsets[i];
 		do_thread_regset_writeback(t->task, regset);
		if (regset->core_note_type &&
 		    (!regset->active || regset->active(t->task, regset))) {
 			int ret;
 			size_t size = regset->n * regset->size;
			void *data = kmalloc(size, GFP_KERNEL);
			if (unlikely(!data))
				return 0;
			ret = regset->get(t->task, regset,
					  0, size, data, NULL);
			if (unlikely(ret))
				kfree(data);
			else {
				if (regset->core_note_type != NT_PRFPREG)
					fill_note(&t->notes[i], "LINUX",
						  regset->core_note_type,
						  size, data);
				else {
					t->prstatus.pr_fpvalid = 1;
					fill_note(&t->notes[i], "CORE",
						  NT_PRFPREG, size, data);
				}
				*total += notesize(&t->notes[i]);
			}
		}
	}

	return 1;
}
Commit message: kernel/sys.c: fix stack memory content leak via UNAME26

Calling uname() with the UNAME26 personality set allows a leak of kernel
stack contents.  This fixes it by defensively calculating the length of
copy_to_user() call, making the len argument unsigned, and initializing
the stack buffer to zero (now technically unneeded, but hey, overkill).

CVE-2012-0957

Reported-by: PaX Team <pageexec@freemail.hu>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CVE: CVE-2012-0957
CWE: CWE-16
Vulnerability description: The override_release function in kernel/sys.c in the Linux kernel before 3.4.16 allows local users to obtain sensitive information from kernel stack memory via a uname system call in conjunction with a UNAME26 personality.

Project: linux
File: sys.c

static int override_release(char __user *release, int len)
 {
 	int ret = 0;
	char buf[65];
 
 	if (current->personality & UNAME26) {
		char *rest = UTS_RELEASE;
 		int ndots = 0;
 		unsigned v;
 
 		while (*rest) {
 			if (*rest == '.' && ++ndots >= 3)
				break;
			if (!isdigit(*rest) && *rest != '.')
				break;
 			rest++;
 		}
 		v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
		snprintf(buf, len, "2.6.%u%s", v, rest);
		ret = copy_to_user(release, buf, len);
 	}
 	return ret;
 }
Commit message: block: Fix io_context leak after clone with CLONE_IO

With CLONE_IO, copy_io() increments both ioc->refcount and ioc->nr_tasks.
However exit_io_context() only decrements ioc->refcount if ioc->nr_tasks
reaches 0.

Always call put_io_context() in exit_io_context().

Signed-off-by: Louis Rilling <louis.rilling@kerlabs.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
CVE: CVE-2012-0879
CWE: CWE-20
Vulnerability description: The I/O implementation for block devices in the Linux kernel before 2.6.33 does not properly handle the CLONE_IO feature, which allows local users to cause a denial of service (I/O instability) by starting multiple processes that share an I/O context.

Project: linux
File: blk-ioc.c

void exit_io_context(void)
{
	struct io_context *ioc;

	task_lock(current);
	ioc = current->io_context;
	current->io_context = NULL;
	task_unlock(current);

	if (atomic_dec_and_test(&ioc->nr_tasks)) {
		if (ioc->aic && ioc->aic->exit)
 			ioc->aic->exit(ioc->aic);
 		cfq_exit(ioc);
 
		put_io_context(ioc);
 	}
 }
Commit message: Fixed stack based buffer overflow in transparent cookie encryption (see separate advisory)
CVE: CVE-2012-0807
CWE: CWE-119
Vulnerability description: Stack-based buffer overflow in the suhosin_encrypt_single_cookie function in the transparent cookie-encryption feature in the Suhosin extension before 0.9.33 for PHP, when suhosin.cookie.encrypt and suhosin.multiheader are enabled, might allow remote attackers to execute arbitrary code via a long string that is used in a Set-Cookie HTTP header.

Project: suhosin
File: header.c

 char *suhosin_encrypt_single_cookie(char *name, int name_len, char *value, int value_len, char *key TSRMLS_DC)
 {
	char buffer[4096];
    char buffer2[4096];
	char *buf = buffer, *buf2 = buffer2, *d, *d_url;
    int l;
	if (name_len > sizeof(buffer)-2) {
		buf = estrndup(name, name_len);
	} else {
		memcpy(buf, name, name_len);
		buf[name_len] = 0;
	}
 	
 	name_len = php_url_decode(buf, name_len);
    normalize_varname(buf);
    name_len = strlen(buf);
 	
 	if (SUHOSIN_G(cookie_plainlist)) {
 		if (zend_hash_exists(SUHOSIN_G(cookie_plainlist), buf, name_len+1)) {
 encrypt_return_plain:
			if (buf != buffer) {
				efree(buf);
			}
 			return estrndup(value, value_len);
 		}
 	} else if (SUHOSIN_G(cookie_cryptlist)) {
		if (!zend_hash_exists(SUHOSIN_G(cookie_cryptlist), buf, name_len+1)) {
			goto encrypt_return_plain;
 		}
 	}
 	
	if (strlen(value) <= sizeof(buffer2)-2) {
		memcpy(buf2, value, value_len);
		buf2[value_len] = 0;
	} else {
		buf2 = estrndup(value, value_len);
	}
 	
 	value_len = php_url_decode(buf2, value_len);
 	
 	d = suhosin_encrypt_string(buf2, value_len, buf, name_len, key TSRMLS_CC);
 	d_url = php_url_encode(d, strlen(d), &l);
 	efree(d);
    if (buf != buffer) {
		efree(buf);
	}
    if (buf2 != buffer2) {
		efree(buf2);
	}
 	return d_url;
 }
Commit message: None
CVE: CVE-2012-0058
CWE: CWE-399
Vulnerability description: The kiocb_batch_free function in fs/aio.c in the Linux kernel before 3.2.2 allows local users to cause a denial of service (OOPS) via vectors that trigger incorrect iocb management.

Project: linux

static void kiocb_batch_free(struct kiocb_batch *batch)
 {
 	struct kiocb *req, *n;
 
 	list_for_each_entry_safe(req, n, &batch->head, ki_batch) {
 		list_del(&req->ki_batch);
 		kmem_cache_free(kiocb_cachep, req);
 	}
 }
Commit message: drm: integer overflow in drm_mode_dirtyfb_ioctl()

There is a potential integer overflow in drm_mode_dirtyfb_ioctl()
if userspace passes in a large num_clips.  The call to kmalloc would
allocate a small buffer, and the call to fb->funcs->dirty may result
in a memory corruption.

Reported-by: Haogang Chen <haogangchen@gmail.com>
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
CVE: CVE-2012-0044
CWE: CWE-189
Vulnerability description: Integer overflow in the drm_mode_dirtyfb_ioctl function in drivers/gpu/drm/drm_crtc.c in the Direct Rendering Manager (DRM) subsystem in the Linux kernel before 3.1.5 allows local users to gain privileges or cause a denial of service (memory corruption) via a crafted ioctl call.

Project: linux

int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
			   void *data, struct drm_file *file_priv)
{
	struct drm_clip_rect __user *clips_ptr;
	struct drm_clip_rect *clips = NULL;
	struct drm_mode_fb_dirty_cmd *r = data;
	struct drm_mode_object *obj;
	struct drm_framebuffer *fb;
	unsigned flags;
	int num_clips;
	int ret = 0;

	if (!drm_core_check_feature(dev, DRIVER_MODESET))
		return -EINVAL;

	mutex_lock(&dev->mode_config.mutex);
	obj = drm_mode_object_find(dev, r->fb_id, DRM_MODE_OBJECT_FB);
	if (!obj) {
		DRM_ERROR("invalid framebuffer id\n");
		ret = -EINVAL;
		goto out_err1;
	}
	fb = obj_to_fb(obj);

	num_clips = r->num_clips;
	clips_ptr = (struct drm_clip_rect *)(unsigned long)r->clips_ptr;

	if (!num_clips != !clips_ptr) {
		ret = -EINVAL;
		goto out_err1;
	}

	flags = DRM_MODE_FB_DIRTY_FLAGS & r->flags;

	/* If userspace annotates copy, clips must come in pairs */
	if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY && (num_clips % 2)) {
		ret = -EINVAL;
		goto out_err1;
 	}
 
 	if (num_clips && clips_ptr) {
 		clips = kzalloc(num_clips * sizeof(*clips), GFP_KERNEL);
 		if (!clips) {
 			ret = -ENOMEM;
			goto out_err1;
		}

		ret = copy_from_user(clips, clips_ptr,
				     num_clips * sizeof(*clips));
		if (ret) {
			ret = -EFAULT;
			goto out_err2;
		}
	}

	if (fb->funcs->dirty) {
		ret = fb->funcs->dirty(fb, file_priv, flags, r->color,
				       clips, num_clips);
	} else {
		ret = -ENOSYS;
		goto out_err2;
	}

out_err2:
	kfree(clips);
out_err1:
	mutex_unlock(&dev->mode_config.mutex);
	return ret;
}
Commit message: perf, powerpc: Handle events that raise an exception without overflowing

Events on POWER7 can roll back if a speculative event doesn't
eventually complete. Unfortunately in some rare cases they will
raise a performance monitor exception. We need to catch this to
ensure we reset the PMC. In all cases the PMC will be 256 or less
cycles from overflow.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org> # as far back as it applies cleanly
LKML-Reference: <20110309143842.6c22845e@kryten>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
CVE: CVE-2011-4611
CWE: CWE-189
Vulnerability description: Integer overflow in the perf_event_interrupt function in arch/powerpc/kernel/perf_event.c in the Linux kernel before 2.6.39 on powerpc platforms allows local users to cause a denial of service (unhandled performance monitor exception) via vectors that trigger certain outcomes of performance events.

Project: linux
File: perf_event.c

static void perf_event_interrupt(struct pt_regs *regs)
{
	int i;
	struct cpu_hw_events *cpuhw = &__get_cpu_var(cpu_hw_events);
	struct perf_event *event;
	unsigned long val;
	int found = 0;
	int nmi;

	if (cpuhw->n_limited)
		freeze_limited_counters(cpuhw, mfspr(SPRN_PMC5),
					mfspr(SPRN_PMC6));

	perf_read_regs(regs);

	nmi = perf_intr_is_nmi(regs);
	if (nmi)
		nmi_enter();
	else
		irq_enter();

	for (i = 0; i < cpuhw->n_events; ++i) {
		event = cpuhw->event[i];
		if (!event->hw.idx || is_limited_pmc(event->hw.idx))
			continue;
		val = read_pmc(event->hw.idx);
		if ((int)val < 0) {
			/* event has overflowed */
			found = 1;
			record_and_restart(event, val, regs, nmi);
		}
	}

	/*
	 * In case we didn't find and reset the event that caused
	 * the interrupt, scan all events and reset any that are
	 * negative, to avoid getting continual interrupts.
	 * Any that we processed in the previous loop will not be negative.
	 */
	if (!found) {
		for (i = 0; i < ppmu->n_counter; ++i) {
 			if (is_limited_pmc(i + 1))
 				continue;
 			val = read_pmc(i + 1);
			if ((int)val < 0)
 				write_pmc(i + 1, 0);
 		}
 	}

	/*
	 * Reset MMCR0 to its normal value.  This will set PMXE and
	 * clear FC (freeze counters) and PMAO (perf mon alert occurred)
	 * and thus allow interrupts to occur again.
	 * XXX might want to use MSR.PM to keep the events frozen until
	 * we get back out of this interrupt.
	 */
	write_mmcr0(cpuhw, cpuhw->mmcr[0]);

	if (nmi)
		nmi_exit();
	else
		irq_exit();
}
Commit message: ipv6: udp: fix the wrong headroom check

At this point, skb->data points to skb_transport_header.
So, headroom check is wrong.

For some case:bridge(UFO is on) + eth device(UFO is off),
there is no enough headroom for IPv6 frag head.
But headroom check is always false.

This will bring about data be moved to there prior to skb->head,
when adding IPv6 frag header to skb.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
CVE: CVE-2011-4326
CWE: CWE-399
Vulnerability description: The udp6_ufo_fragment function in net/ipv6/udp.c in the Linux kernel before 2.6.39, when a certain UDP Fragmentation Offload (UFO) configuration is enabled, allows remote attackers to cause a denial of service (system crash) by sending fragmented IPv6 UDP packets to a bridge device.

Project: linux
File: udp.c

static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, u32 features)
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	unsigned int mss;
	unsigned int unfrag_ip6hlen, unfrag_len;
	struct frag_hdr *fptr;
	u8 *mac_start, *prevhdr;
	u8 nexthdr;
	u8 frag_hdr_sz = sizeof(struct frag_hdr);
	int offset;
	__wsum csum;

	mss = skb_shinfo(skb)->gso_size;
	if (unlikely(skb->len <= mss))
		goto out;

	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
		/* Packet is from an untrusted source, reset gso_segs. */
		int type = skb_shinfo(skb)->gso_type;

		if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY) ||
			     !(type & (SKB_GSO_UDP))))
			goto out;

		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);

		segs = NULL;
		goto out;
	}

	/* Do software UFO. Complete and fill in the UDP checksum as HW cannot
	 * do checksum of UDP packets sent as multiple IP fragments.
	 */
	offset = skb->csum_start - skb_headroom(skb);
	csum = skb_checksum(skb, offset, skb->len- offset, 0);
	offset += skb->csum_offset;
	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
 	skb->ip_summed = CHECKSUM_NONE;
 
 	/* Check if there is enough headroom to insert fragment header. */
	if ((skb_headroom(skb) < frag_hdr_sz) &&
 	    pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC))
 		goto out;
 
	/* Find the unfragmentable header and shift it left by frag_hdr_sz
	 * bytes to insert fragment header.
	 */
	unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr);
	nexthdr = *prevhdr;
	*prevhdr = NEXTHDR_FRAGMENT;
	unfrag_len = skb_network_header(skb) - skb_mac_header(skb) +
		     unfrag_ip6hlen;
	mac_start = skb_mac_header(skb);
	memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len);

	skb->mac_header -= frag_hdr_sz;
	skb->network_header -= frag_hdr_sz;

	fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
	fptr->nexthdr = nexthdr;
	fptr->reserved = 0;
	ipv6_select_ident(fptr);

	/* Fragment the skb. ipv6 header and the remaining fields of the
	 * fragment header are updated in ipv6_gso_segment()
	 */
	segs = skb_segment(skb, features);

out:
	return segs;
}