<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/git/stable/linux.git/drivers/bluetooth/h4_recv.h, branch master</title>
<subtitle>Linux kernel stable tree</subtitle>
<id>https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=master</id>
<link rel='self' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=master'/>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/'/>
<updated>2025-09-27T15:37:01+00:00</updated>
<entry>
<title>Bluetooth: remove duplicate h4_recv_buf() in header</title>
<updated>2025-09-27T15:37:01+00:00</updated>
<author>
<name>Calvin Owens</name>
<email>calvin@wbinvd.org</email>
</author>
<published>2025-08-26T04:11:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=93f06f8f0daf43d87b4f61a3535a9cda62c61dd7'/>
<id>urn:sha1:93f06f8f0daf43d87b4f61a3535a9cda62c61dd7</id>
<content type='text'>
The "h4_recv.h" header contains a duplicate h4_recv_buf() that is nearly
but not quite identical to the h4_recv_buf() in hci_h4.c.

This duplicated header was added in commit 07eb96a5a7b0 ("Bluetooth:
bpa10x: Use separate h4_recv_buf helper"). I wasn't able to find any
explanation for duplicating the code in the discussion:

    https://lore.kernel.org/all/20180320181855.37297-1-marcel@holtmann.org/
    https://lore.kernel.org/all/20180324091954.73229-2-marcel@holtmann.org/

Unfortunately, in the years since, several other drivers have come to
also rely on this duplicated function, probably by accident. This is, at
the very least, *extremely* confusing. It's also caused real issues when
it's become out-of-sync, see the following:

    ef564119ba83 ("Bluetooth: hci_h4: Add support for ISO packets")
    61b27cdf025b ("Bluetooth: hci_h4: Add support for ISO packets in h4_recv.h")

This is the full diff between the two implementations today:

    --- orig.c
    +++ copy.c
    @@ -1,117 +1,100 @@
     {
    -	struct hci_uart *hu = hci_get_drvdata(hdev);
    -	u8 alignment = hu-&gt;alignment ? hu-&gt;alignment : 1;
    -
     	/* Check for error from previous call */
     	if (IS_ERR(skb))
     		skb = NULL;

     	while (count) {
     		int i, len;

    -		/* remove padding bytes from buffer */
    -		for (; hu-&gt;padding &amp;&amp; count &gt; 0; hu-&gt;padding--) {
    -			count--;
    -			buffer++;
    -		}
    -		if (!count)
    -			break;
    -
     		if (!skb) {
     			for (i = 0; i &lt; pkts_count; i++) {
     				if (buffer[0] != (&amp;pkts[i])-&gt;type)
     					continue;

     				skb = bt_skb_alloc((&amp;pkts[i])-&gt;maxlen,
     						   GFP_ATOMIC);
     				if (!skb)
     					return ERR_PTR(-ENOMEM);

     				hci_skb_pkt_type(skb) = (&amp;pkts[i])-&gt;type;
     				hci_skb_expect(skb) = (&amp;pkts[i])-&gt;hlen;
     				break;
     			}

     			/* Check for invalid packet type */
     			if (!skb)
     				return ERR_PTR(-EILSEQ);

     			count -= 1;
     			buffer += 1;
     		}

     		len = min_t(uint, hci_skb_expect(skb) - skb-&gt;len, count);
     		skb_put_data(skb, buffer, len);

     		count -= len;
     		buffer += len;

     		/* Check for partial packet */
     		if (skb-&gt;len &lt; hci_skb_expect(skb))
     			continue;

     		for (i = 0; i &lt; pkts_count; i++) {
     			if (hci_skb_pkt_type(skb) == (&amp;pkts[i])-&gt;type)
     				break;
     		}

     		if (i &gt;= pkts_count) {
     			kfree_skb(skb);
     			return ERR_PTR(-EILSEQ);
     		}

     		if (skb-&gt;len == (&amp;pkts[i])-&gt;hlen) {
     			u16 dlen;

     			switch ((&amp;pkts[i])-&gt;lsize) {
     			case 0:
     				/* No variable data length */
     				dlen = 0;
     				break;
     			case 1:
     				/* Single octet variable length */
     				dlen = skb-&gt;data[(&amp;pkts[i])-&gt;loff];
     				hci_skb_expect(skb) += dlen;

     				if (skb_tailroom(skb) &lt; dlen) {
     					kfree_skb(skb);
     					return ERR_PTR(-EMSGSIZE);
     				}
     				break;
     			case 2:
     				/* Double octet variable length */
     				dlen = get_unaligned_le16(skb-&gt;data +
     							  (&amp;pkts[i])-&gt;loff);
     				hci_skb_expect(skb) += dlen;

     				if (skb_tailroom(skb) &lt; dlen) {
     					kfree_skb(skb);
     					return ERR_PTR(-EMSGSIZE);
     				}
     				break;
     			default:
     				/* Unsupported variable length */
     				kfree_skb(skb);
     				return ERR_PTR(-EILSEQ);
     			}

     			if (!dlen) {
    -				hu-&gt;padding = (skb-&gt;len + 1) % alignment;
    -				hu-&gt;padding = (alignment - hu-&gt;padding) % alignment;
    -
     				/* No more data, complete frame */
     				(&amp;pkts[i])-&gt;recv(hdev, skb);
     				skb = NULL;
     			}
     		} else {
    -			hu-&gt;padding = (skb-&gt;len + 1) % alignment;
    -			hu-&gt;padding = (alignment - hu-&gt;padding) % alignment;
    -
     			/* Complete frame */
     			(&amp;pkts[i])-&gt;recv(hdev, skb);
     			skb = NULL;
     		}
     	}

     	return skb;
     }
    -EXPORT_SYMBOL_GPL(h4_recv_buf)

As I read this: If alignment is one, and padding is zero, padding
remains zero throughout the loop. So it seems to me that the two
functions behave strictly identically in that case. All the duplicated
defines are also identical, as is the duplicated h4_recv_pkt structure
declaration.

All four drivers which use the duplicated function use the default
alignment of one, and the default padding of zero. I therefore conclude
the duplicate function may be safely replaced with the core one.

I raised this in an RFC a few months ago, and didn't get much interest:

    https://lore.kernel.org/all/CABBYNZ+ONkYtq2fR-8PtL3X-vetvJ0BdP4MTw9cNpjLDzG3HUQ@mail.gmail.com/

...but I'm still wary I've missed something, and I'd really appreciate
more eyeballs on it.

I tested this successfully on btnxpuart a few months ago, but
unfortunately I no longer have access to that hardware.

Cc: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Signed-off-by: Calvin Owens &lt;calvin@wbinvd.org&gt;
Reviewed-by: Paul Menzel &lt;pmenzel@molgen.mpg.de&gt;
Signed-off-by: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
</content>
</entry>
<entry>
<title>move asm/unaligned.h to linux/unaligned.h</title>
<updated>2024-10-02T21:23:23+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2024-10-01T19:35:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5f60d5f6bbc12e782fac78110b0ee62698f3b576'/>
<id>urn:sha1:5f60d5f6bbc12e782fac78110b0ee62698f3b576</id>
<content type='text'>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
</content>
</entry>
<entry>
<title>Bluetooth: hci_h4: Add support for ISO packets in h4_recv.h</title>
<updated>2024-09-10T17:04:05+00:00</updated>
<author>
<name>Neeraj Sanjay Kale</name>
<email>neeraj.sanjaykale@nxp.com</email>
</author>
<published>2024-08-16T11:13:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=61b27cdf025bf47d3caf0f1ceab078b48774ba13'/>
<id>urn:sha1:61b27cdf025bf47d3caf0f1ceab078b48774ba13</id>
<content type='text'>
This adds ISO packet support in h4_recv.h, which was created before ISO
packet handling was added to hci_h4.c and hci_uart.c

Signed-off-by: Neeraj Sanjay Kale &lt;neeraj.sanjaykale@nxp.com&gt;
Signed-off-by: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
</content>
</entry>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156</title>
<updated>2019-05-30T18:26:35+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-05-27T06:55:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1a59d1b8e05ea6ab45f7e18897de1ef0e6bc3da6'/>
<id>urn:sha1:1a59d1b8e05ea6ab45f7e18897de1ef0e6bc3da6</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Reviewed-by: Richard Fontana &lt;rfontana@redhat.com&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>Bluetooth: remove redundant zero check on count</title>
<updated>2019-02-18T10:46:45+00:00</updated>
<author>
<name>Colin Ian King</name>
<email>colin.king@canonical.com</email>
</author>
<published>2019-02-04T19:03:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=761f1e9f99b2cec66397db59a8f77ff6cbbfa536'/>
<id>urn:sha1:761f1e9f99b2cec66397db59a8f77ff6cbbfa536</id>
<content type='text'>
Variable count is never zero inside the loop so the check if count is
zero is redundant and can be removed. Fix this.

Detected by CoverityScan, CID#1466880 ("Logically dead code")

Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Signed-off-by: Marcel Holtmann &lt;marcel@holtmann.org&gt;
</content>
</entry>
<entry>
<title>Bluetooth: hci_uart: Check if socket buffer is ERR_PTR in h4_recv_buf()</title>
<updated>2019-01-22T08:51:19+00:00</updated>
<author>
<name>Myungho Jung</name>
<email>mhjungk@gmail.com</email>
</author>
<published>2019-01-22T08:33:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1dc2d785156cbdc80806c32e8d2c7c735d0b4721'/>
<id>urn:sha1:1dc2d785156cbdc80806c32e8d2c7c735d0b4721</id>
<content type='text'>
h4_recv_buf() callers store the return value to socket buffer and
recursively pass the buffer to h4_recv_buf() without protection. So,
ERR_PTR returned from h4_recv_buf() can be dereferenced, if called again
before setting the socket buffer to NULL from previous error. Check if
skb is ERR_PTR in h4_recv_buf().

Reported-by: syzbot+017a32f149406df32703@syzkaller.appspotmail.com
Signed-off-by: Myungho Jung &lt;mhjungk@gmail.com&gt;
Signed-off-by: Marcel Holtmann &lt;marcel@holtmann.org&gt;
</content>
</entry>
<entry>
<title>Bluetooth: bpa10x: Use separate h4_recv_buf helper</title>
<updated>2018-04-01T12:25:32+00:00</updated>
<author>
<name>Marcel Holtmann</name>
<email>marcel@holtmann.org</email>
</author>
<published>2018-03-24T09:19:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=07eb96a5a7b083c988a2c7b0663e958e392f18c7'/>
<id>urn:sha1:07eb96a5a7b083c988a2c7b0663e958e392f18c7</id>
<content type='text'>
When adding the alignment and padding support for H:4 packet processing
for the Nokia driver, it broke the h4_recv_buf usage within bpa10x
driver. To fix this use a separate helper function and placing it into a
dedicated h4_recv.h header file.

Signed-off-by: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Signed-off-by: Johan Hedberg &lt;johan.hedberg@intel.com&gt;
</content>
</entry>
</feed>
