Blob Blame History Raw
From 87f7a20da7834fef4fe45c42a10faeb3f1c07dbc Mon Sep 17 00:00:00 2001
From: Yannick Cote <ycote@redhat.com>
Date: Mon, 12 Dec 2022 12:13:31 -0500
Subject: [KPATCH CVE-2022-2964] kpatch fixes for CVE-2022-2964

Kernels:
5.14.0-162.6.1.el9_1


Kpatch-MR: https://gitlab.com/redhat/prdsc/rhel/src/kpatch/rhel-9/-/merge_requests/11
Approved-by: Joe Lawrence (@joe.lawrence)
Changes since last build:
[x86_64]:
ax88179_178a.o: changed function: ax88179_rx_fixup
callback_xdr.o: changed function: nfs_callback_dispatch
intel_gt.o: changed function: intel_gt_invalidate_tlbs
nfs3proc.o: changed function: nfsd3_init_dirlist_pages
nfs3proc.o: changed function: nfsd3_proc_read
nfsproc.o: changed function: nfsd_proc_read
nfsproc.o: changed function: nfsd_proc_readdir
nfssvc.o: changed function: nfsd_dispatch
pipe.o: changed function: pipe_resize_ring
svc.o: changed function: nlmsvc_dispatch

[ppc64le]:
ax88179_178a.o: changed function: ax88179_rx_fixup
callback_xdr.o: changed function: nfs_callback_dispatch
nfs3proc.o: changed function: nfsd3_init_dirlist_pages
nfs3proc.o: changed function: nfsd3_proc_read
nfsproc.o: changed function: nfsd_proc_read
nfsproc.o: changed function: nfsd_proc_readdir
nfssvc.o: changed function: nfsd_dispatch
pipe.o: changed function: pipe_resize_ring
svc.o: changed function: nlmsvc_dispatch

---------------------------

Modifications: none

commit 6274d41609abb0959136a4a2ee687d79fa765a14
Author: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
Date:   Tue Nov 15 17:07:42 2022 +0100

    net: usb: ax88179_178a: Fix out-of-bounds accesses in RX fixup

    Bugzilla: https://bugzilla.redhat.com/2142722
    CVE: CVE-2022-2964
    Y-Commit: 1851b951feb91882a180d1c4924d7f03389a9435

    O-Bugzilla: https://bugzilla.redhat.com/2142723
    O-CVE: CVE-2022-2964

    commit 57bc3d3ae8c14df3ceb4e17d26ddf9eeab304581
    Author: Jann Horn <jannh@google.com>
    Date:   Wed Jan 26 14:14:52 2022 +0100

        net: usb: ax88179_178a: Fix out-of-bounds accesses in RX fixup

        ax88179_rx_fixup() contains several out-of-bounds accesses that can be
        triggered by a malicious (or defective) USB device, in particular:

         - The metadata array (hdr_off..hdr_off+2*pkt_cnt) can be out of bounds,
           causing OOB reads and (on big-endian systems) OOB endianness flips.
         - A packet can overlap the metadata array, causing a later OOB
           endianness flip to corrupt data used by a cloned SKB that has already
           been handed off into the network stack.
         - A packet SKB can be constructed whose tail is far beyond its end,
           causing out-of-bounds heap data to be considered part of the SKB's
           data.

        I have tested that this can be used by a malicious USB device to send a
        bogus ICMPv6 Echo Request and receive an ICMPv6 Echo Reply in response
        that contains random kernel heap data.
        It's probably also possible to get OOB writes from this on a
        little-endian system somehow - maybe by triggering skb_cow() via IP
        options processing -, but I haven't tested that.

        Fixes: e2ca90c276e1 ("ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to gigabit ethernet adapter driver")
        Cc: stable@kernel.org
        Signed-off-by: Jann Horn <jannh@google.com>
        Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

    Signed-off-by: Patrick Talbert <ptalbert@redhat.com>

commit ed49211cd6a1a99bc1e3450fbafaf75865e11037
Author: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>
Date:   Wed Nov 16 12:43:01 2022 +0100

    net: usb: ax88179_178a: Fix packet receiving

    Bugzilla: https://bugzilla.redhat.com/2142722
    CVE: CVE-2022-2964
    Y-Commit: c18d44fdacbbf489eb38e2db9b0ae66b4ad036dd

    O-Bugzilla: https://bugzilla.redhat.com/2142723
    O-CVE: CVE-2022-2964

    commit f8ebb3ac881b17712e1d5967c97ab1806b16d3d6
    Author: Jose Alonso <joalonsof@gmail.com>
    Date:   Tue Jun 28 12:13:02 2022 -0300

        net: usb: ax88179_178a: Fix packet receiving

        This patch corrects packet receiving in ax88179_rx_fixup.

        - problem observed:
          ifconfig shows allways a lot of 'RX Errors' while packets
          are received normally.

          This occurs because ax88179_rx_fixup does not recognise properly
          the usb urb received.
          The packets are normally processed and at the end, the code exits
          with 'return 0', generating RX Errors.
          (pkt_cnt==-2 and ptk_hdr over field rx_hdr trying to identify
           another packet there)

          This is a usb urb received by "tcpdump -i usbmon2 -X" on a
          little-endian CPU:
          0x0000:  eeee f8e3 3b19 87a0 94de 80e3 daac 0800
                   ^         packet 1 start (pkt_len = 0x05ec)
                   ^^^^      IP alignment pseudo header
                        ^    ethernet packet start
                   last byte ethernet packet   v
                   padding (8-bytes aligned)     vvvv vvvv
          0x05e0:  c92d d444 1420 8a69 83dd 272f e82b 9811
          0x05f0:  eeee f8e3 3b19 87a0 94de 80e3 daac 0800
          ...      ^ packet 2
          0x0be0:  eeee f8e3 3b19 87a0 94de 80e3 daac 0800
          ...
          0x1130:  9d41 9171 8a38 0ec5 eeee f8e3 3b19 87a0
          ...
          0x1720:  8cfc 15ff 5e4c e85c eeee f8e3 3b19 87a0
          ...
          0x1d10:  ecfa 2a3a 19ab c78c eeee f8e3 3b19 87a0
          ...
          0x2070:  eeee f8e3 3b19 87a0 94de 80e3 daac 0800
          ...      ^ packet 7
          0x2120:  7c88 4ca5 5c57 7dcc 0d34 7577 f778 7e0a
          0x2130:  f032 e093 7489 0740 3008 ec05 0000 0080
                                       ====1==== ====2====
                   hdr_off             ^
                   pkt_len = 0x05ec         ^^^^
                   AX_RXHDR_*=0x00830  ^^^^   ^
                   pkt_len = 0                        ^^^^
                   AX_RXHDR_DROP_ERR=0x80000000  ^^^^   ^
          0x2140:  3008 ec05 0000 0080 3008 5805 0000 0080
          0x2150:  3008 ec05 0000 0080 3008 ec05 0000 0080
          0x2160:  3008 5803 0000 0080 3008 c800 0000 0080
                   ===11==== ===12==== ===13==== ===14====
          0x2170:  0000 0000 0e00 3821
                             ^^^^ ^^^^ rx_hdr
                             ^^^^      pkt_cnt=14
                                  ^^^^ hdr_off=0x2138
                   ^^^^ ^^^^           padding

          The dump shows that pkt_cnt is the number of entrys in the
          per-packet metadata. It is "2 * packet count".
          Each packet have two entrys. The first have a valid
          value (pkt_len and AX_RXHDR_*) and the second have a
          dummy-header 0x80000000 (pkt_len=0 with AX_RXHDR_DROP_ERR).
          Why exists dummy-header for each packet?!?
          My guess is that this was done probably to align the
          entry for each packet to 64-bits and maintain compatibility
          with old firmware.
          There is also a padding (0x00000000) before the rx_hdr to
          align the end of rx_hdr to 64-bit.
          Note that packets have a alignment of 64-bits (8-bytes).

          This patch assumes that the dummy-header and the last
          padding are optional. So it preserves semantics and
          recognises the same valid packets as the current code.

          This patch was made using only the dumpfile information and
          tested with only one device:
          0b95:1790 ASIX Electronics Corp. AX88179 Gigabit Ethernet

        Fixes: 57bc3d3ae8c1 ("net: usb: ax88179_178a: Fix out-of-bounds accesses in RX fixup")
        Fixes: e2ca90c276e1 ("ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to gigabit ethernet adapter driver")
        Signed-off-by: Jose Alonso <joalonsof@gmail.com>
        Acked-by: Paolo Abeni <pabeni@redhat.com>
        Link: https://lore.kernel.org/r/d6970bb04bf67598af4d316eaeb1792040b18cfd.camel@gmail.com
        Signed-off-by: Paolo Abeni <pabeni@redhat.com>

    Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

    Signed-off-by: Patrick Talbert <ptalbert@redhat.com>

Signed-off-by: Yannick Cote <ycote@redhat.com>
---
 drivers/net/usb/ax88179_178a.c | 113 +++++++++++++++++++++++++--------
 1 file changed, 87 insertions(+), 26 deletions(-)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index 5ed59d9dd631..5aa4e53a6d75 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1467,58 +1467,119 @@ static int ax88179_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 	u16 hdr_off;
 	u32 *pkt_hdr;
 
-	/* This check is no longer done by usbnet */
-	if (skb->len < dev->net->hard_header_len)
+	/* At the end of the SKB, there's a header telling us how many packets
+	 * are bundled into this buffer and where we can find an array of
+	 * per-packet metadata (which contains elements encoded into u16).
+	 */
+
+	/* SKB contents for current firmware:
+	 *   <packet 1> <padding>
+	 *   ...
+	 *   <packet N> <padding>
+	 *   <per-packet metadata entry 1> <dummy header>
+	 *   ...
+	 *   <per-packet metadata entry N> <dummy header>
+	 *   <padding2> <rx_hdr>
+	 *
+	 * where:
+	 *   <packet N> contains pkt_len bytes:
+	 *		2 bytes of IP alignment pseudo header
+	 *		packet received
+	 *   <per-packet metadata entry N> contains 4 bytes:
+	 *		pkt_len and fields AX_RXHDR_*
+	 *   <padding>	0-7 bytes to terminate at
+	 *		8 bytes boundary (64-bit).
+	 *   <padding2> 4 bytes to make rx_hdr terminate at
+	 *		8 bytes boundary (64-bit)
+	 *   <dummy-header> contains 4 bytes:
+	 *		pkt_len=0 and AX_RXHDR_DROP_ERR
+	 *   <rx-hdr>	contains 4 bytes:
+	 *		pkt_cnt and hdr_off (offset of
+	 *		  <per-packet metadata entry 1>)
+	 *
+	 * pkt_cnt is number of entrys in the per-packet metadata.
+	 * In current firmware there is 2 entrys per packet.
+	 * The first points to the packet and the
+	 *  second is a dummy header.
+	 * This was done probably to align fields in 64-bit and
+	 *  maintain compatibility with old firmware.
+	 * This code assumes that <dummy header> and <padding2> are
+	 *  optional.
+	 */
+
+	if (skb->len < 4)
 		return 0;
-
 	skb_trim(skb, skb->len - 4);
 	rx_hdr = get_unaligned_le32(skb_tail_pointer(skb));
-
 	pkt_cnt = (u16)rx_hdr;
 	hdr_off = (u16)(rx_hdr >> 16);
+
+	if (pkt_cnt == 0)
+		return 0;
+
+	/* Make sure that the bounds of the metadata array are inside the SKB
+	 * (and in front of the counter at the end).
+	 */
+	if (pkt_cnt * 4 + hdr_off > skb->len)
+		return 0;
 	pkt_hdr = (u32 *)(skb->data + hdr_off);
 
-	while (pkt_cnt--) {
+	/* Packets must not overlap the metadata array */
+	skb_trim(skb, hdr_off);
+
+	for (; pkt_cnt > 0; pkt_cnt--, pkt_hdr++) {
+		u16 pkt_len_plus_padd;
 		u16 pkt_len;
 
 		le32_to_cpus(pkt_hdr);
 		pkt_len = (*pkt_hdr >> 16) & 0x1fff;
+		pkt_len_plus_padd = (pkt_len + 7) & 0xfff8;
+
+		/* Skip dummy header used for alignment
+		 */
+		if (pkt_len == 0)
+			continue;
+
+		if (pkt_len_plus_padd > skb->len)
+			return 0;
 
 		/* Check CRC or runt packet */
-		if ((*pkt_hdr & AX_RXHDR_CRC_ERR) ||
-		    (*pkt_hdr & AX_RXHDR_DROP_ERR)) {
-			skb_pull(skb, (pkt_len + 7) & 0xFFF8);
-			pkt_hdr++;
+		if ((*pkt_hdr & (AX_RXHDR_CRC_ERR | AX_RXHDR_DROP_ERR)) ||
+		    pkt_len < 2 + ETH_HLEN) {
+			dev->net->stats.rx_errors++;
+			skb_pull(skb, pkt_len_plus_padd);
 			continue;
 		}
 
-		if (pkt_cnt == 0) {
-			skb->len = pkt_len;
+		/* last packet */
+		if (pkt_len_plus_padd == skb->len) {
+			skb_trim(skb, pkt_len);
+
 			/* Skip IP alignment pseudo header */
 			skb_pull(skb, 2);
-			skb_set_tail_pointer(skb, skb->len);
-			skb->truesize = pkt_len + sizeof(struct sk_buff);
+
+			skb->truesize = SKB_TRUESIZE(pkt_len_plus_padd);
 			ax88179_rx_checksum(skb, pkt_hdr);
 			return 1;
 		}
 
 		ax_skb = skb_clone(skb, GFP_ATOMIC);
-		if (ax_skb) {
-			ax_skb->len = pkt_len;
-			/* Skip IP alignment pseudo header */
-			skb_pull(ax_skb, 2);
-			skb_set_tail_pointer(ax_skb, ax_skb->len);
-			ax_skb->truesize = pkt_len + sizeof(struct sk_buff);
-			ax88179_rx_checksum(ax_skb, pkt_hdr);
-			usbnet_skb_return(dev, ax_skb);
-		} else {
+		if (!ax_skb)
 			return 0;
-		}
+		skb_trim(ax_skb, pkt_len);
+
+		/* Skip IP alignment pseudo header */
+		skb_pull(ax_skb, 2);
+
+		skb->truesize = pkt_len_plus_padd +
+				SKB_DATA_ALIGN(sizeof(struct sk_buff));
+		ax88179_rx_checksum(ax_skb, pkt_hdr);
+		usbnet_skb_return(dev, ax_skb);
 
-		skb_pull(skb, (pkt_len + 7) & 0xFFF8);
-		pkt_hdr++;
+		skb_pull(skb, pkt_len_plus_padd);
 	}
-	return 1;
+
+	return 0;
 }
 
 static struct sk_buff *
-- 
2.39.0