Nicolas Bidron and Nicolas Guigo reported the two bugs below:
"
----------BUG 1----------
In compiled versions of U-Boot that define CONFIG_IP_DEFRAG, a value of
`ip->ip_len` (IP packet header's Total Length) higher than `IP_HDR_SIZE`
and strictly lower than `IP_HDR_SIZE+8` will lead to a value for `len`
comprised between `0` and `7`. This will ultimately result in a
truncated division by `8` resulting value of `0` forcing the hole
metadata and fragment to point to the same location. The subsequent
memcopy will overwrite the hole metadata with the fragment data. Through
a second fragment, this can be exploited to write to an arbitrary offset
controlled by that overwritten hole metadata value.
This bug is only exploitable locally as it requires crafting two packets
the first of which would most likely be dropped through routing due to
its unexpectedly low Total Length. However, this bug can potentially be
exploited to root linux based embedded devices locally.
```C
static struct ip_udp_hdr *__net_defragment(struct ip_udp_hdr *ip, int *lenp)
{
static uchar pkt_buff[IP_PKTSIZE] __aligned(PKTALIGN);
static u16 first_hole, total_len;
struct hole *payload, *thisfrag, *h, *newh;
struct ip_udp_hdr *localip = (struct ip_udp_hdr *)pkt_buff;
uchar *indata = (uchar *)ip;
int offset8, start, len, done = 0;
u16 ip_off = ntohs(ip->ip_off);
/* payload starts after IP header, this fragment is in there */
payload = (struct hole *)(pkt_buff + IP_HDR_SIZE);
offset8 = (ip_off & IP_OFFS);
thisfrag = payload + offset8;
start = offset8 * 8;
len = ntohs(ip->ip_len) - IP_HDR_SIZE;
```
The last line of the previous excerpt from `u-boot/net/net.c` shows how
the attacker can control the value of `len` to be strictly lower than
`8` by issuing a packet with `ip_len` between `21` and `27`
(`IP_HDR_SIZE` has a value of `20`).
Also note that `offset8` here is `0` which leads to `thisfrag = payload`.
```C
} else if (h >= thisfrag) {
/* overlaps with initial part of the hole: move this hole */
newh = thisfrag + (len / 8);
*newh = *h;
h = newh;
if (h->next_hole)
payload[h->next_hole].prev_hole = (h - payload);
if (h->prev_hole)
payload[h->prev_hole].next_hole = (h - payload);
else
first_hole = (h - payload);
} else {
```
Lower down the same function, execution reaches the above code path.
Here, `len / 8` evaluates to `0` leading to `newh = thisfrag`. Also note
that `first_hole` here is `0` since `h` and `payload` point to the same
location.
```C
/* finally copy this fragment and possibly return whole packet */
memcpy((uchar *)thisfrag, indata + IP_HDR_SIZE, len);
```
Finally, in the above excerpt the `memcpy` overwrites the hole metadata
since `thisfrag` and `h` both point to the same location. The hole
metadata is effectively overwritten with arbitrary data from the
fragmented IP packet data. If `len` was crafted to be `6`, `last_byte`,
`next_hole`, and `prev_hole` of the `first_hole` can be controlled by
the attacker.
Finally the arbitrary offset write occurs through a second fragment that
only needs to be crafted to write data in the hole pointed to by the
previously controlled hole metadata (`next_hole`) from the first packet.
### Recommendation
Handle cases where `len` is strictly lower than 8 by preventing the
overwrite of the hole metadata during the memcpy of the fragment. This
could be achieved by either:
* Moving the location where the hole metadata is stored when `len` is
lower than `8`.
* Or outright rejecting fragmented IP datagram with a Total Length
(`ip_len`) lower than 28 bytes which is the minimum valid fragmented IP
datagram size (as defined as the minimum fragment of 8 octets in the IP
Specification Document:
[RFC791](https://datatracker.ietf.org/doc/html/rfc791) page 25).
----------BUG 2----------
In compiled versions of U-Boot that define CONFIG_IP_DEFRAG, a value of
`ip->ip_len` (IP packet header's Total Length) lower than `IP_HDR_SIZE`
will lead to a negative value for `len` which will ultimately result in
a buffer overflow during the subsequent `memcpy` that uses `len` as it's
`count` parameter.
This bug is only exploitable on local ethernet as it requires crafting
an invalid packet to include an unexpected `ip_len` value in the IP UDP
header that's lower than the minimum accepted Total Length of a packet
(21 as defined in the IP Specification Document:
[RFC791](https://datatracker.ietf.org/doc/html/rfc791)). Such packet
would in all likelihood be dropped while being routed to its final
destination through most routing equipment and as such requires the
attacker to be in a local position in order to be exploited.
```C
static struct ip_udp_hdr *__net_defragment(struct ip_udp_hdr *ip, int *lenp)
{
static uchar pkt_buff[IP_PKTSIZE] __aligned(PKTALIGN);
static u16 first_hole, total_len;
struct hole *payload, *thisfrag, *h, *newh;
struct ip_udp_hdr *localip = (struct ip_udp_hdr *)pkt_buff;
uchar *indata = (uchar *)ip;
int offset8, start, len, done = 0;
u16 ip_off = ntohs(ip->ip_off);
/* payload starts after IP header, this fragment is in there */
payload = (struct hole *)(pkt_buff + IP_HDR_SIZE);
offset8 = (ip_off & IP_OFFS);
thisfrag = payload + offset8;
start = offset8 * 8;
len = ntohs(ip->ip_len) - IP_HDR_SIZE;
```
The last line of the previous excerpt from `u-boot/net/net.c` shows
where the underflow to a negative `len` value occurs if `ip_len` is set
to a value strictly lower than 20 (`IP_HDR_SIZE` being 20). Also note
that in the above excerpt the `pkt_buff` buffer has a size of
`CONFIG_NET_MAXDEFRAG` which defaults to 16 KB but can range from 1KB to
64 KB depending on configurations.
```C
/* finally copy this fragment and possibly return whole packet */
memcpy((uchar *)thisfrag, indata + IP_HDR_SIZE, len);
```
In the above excerpt the `memcpy` overflows the destination by
attempting to make a copy of nearly 4 gigabytes in a buffer that's
designed to hold `CONFIG_NET_MAXDEFRAG` bytes at most which leads to a DoS.
### Recommendation
Stop processing of the packet if `ip_len` is lower than 21 (as defined
by the minimum length of a data carrying datagram in the IP
Specification Document:
[RFC791](https://datatracker.ietf.org/doc/html/rfc791) page 34)."
Add a check for ip_len lesser than 28 and stop processing the packet
in this case.
Such a check covers the two reported bugs.
Reported-by: Nicolas Bidron <nicolas.bidron@nccgroup.com>
Signed-off-by: Fabio Estevam <festevam@denx.de>
- U-boot's PXE flow supports prefixing your bootfile name with an
IP address to fetch from a server other than the DHCP server,
e.g. `hostIPaddr:bootfilename`:
a93907c43f
- However, this breaks bootfile paths which contain a colon, e.g.
`f0:ad:4e:10:1b:87/7/pxelinux.cfg/default`
- This patch checks whether the `hostIPaddr` prefix is a valid
IP address before overriding the serverIP otherwise the whole
bootfile path is preserved
Signed-off-by: Lyle Franklin <lylejfranklin@gmail.com>
Use IS_ENABLED() instead, to reduce the number of build paths.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
It is a pain to have to specify the value 10 in each call. Add a new
dectoul() function and update the code to use it.
Signed-off-by: Simon Glass <sjg@chromium.org>
net_init does not always succeed, and there is no existing mechanism to
discover errors. This patch allows callers of net_init (such as net_init)
to handle errors. The root issue is that eth_get_dev can fail, but
net_init_loop doesn't expose that. The ideal way to fix eth_get_dev would
be to return an error with ERR_PTR, but there are a lot of callers, and all
of them just check if it's NULL. Another approach would be to change the
signature to something like
int eth_get_dev(struct udevice **pdev)
but that would require rewriting all of the many callers.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commits update the support of sntp to use
the framework udp. This change allows to remove
all the reference to sntp in the main network
file net/net.c.
Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit adds a generic udp protocol framework in the
network loop. So protocol based on udp may be implemented
without modifying the network loop (for example custom
wait magic packet).
Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reset the stored ping IP address before entering a netloop with different
protocol to ensure that it won't be interrupted by the received
correct ICMP_ECHO_REPLY packet.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
The random_port() routine is not used anywhere else. Make it local to
dns.c to reduce code clutter, and shrink generated code a little.
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
If 'CONFIG_CMD_TFTPBOOT' or 'CONFIG_CMD_BOOTP' are disabled, the usage must be disabled, too!
Signed-off-by: Olaf Krebs <olaf.krebs@emh-metering.com>
CC: Joe Hershberger <joe.hershberger@ni.com>
These global variables are quite short and generic. In fact the same name
is more often used locally for struct members and function arguments.
Add a image_ prefix to make them easier to distinguish.
Signed-off-by: Simon Glass <sjg@chromium.org>
sandbox_defconfig does not compile using GCC 9.2.1:
net/net.c: In function ‘net_process_received_packet’:
net/net.c:1288:23: error: taking address of packed member of ‘struct
ip_udp_hdr’ may result in an unaligned pointer value
[-Werror=address-of-packed-member]
1288 | sumptr = (ushort *)&(ip->udp_src);
| ^~~~~~~~~~~~~~
Avoid the error by using a u8 pointer instead of an u16 pointer and
in-lining ntohs().
Simplify the checksumming of the last message byte.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
While we have networking use cases within SPL we do not support loading
files via NFS at this point in time. Disable calling nfs_start() so
that the NFS related code can be garbage collected at link time.
Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Part of the env cleanup moved this out of the environment code and into
the net code. However, this helper is sometimes needed even when the net
stack isn't included.
Move the helper to lib/net_utils.c like it's similarly-purposed
string_to_ip(). Also rename the moved function to similar naming.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reported-by: Ondrej Jirman <megous@megous.com>
This patch adds a check to udp_len to fix unbounded memcpy for
CVE-2019-14192, CVE-2019-14193 and CVE-2019-14199.
Signed-off-by: Cheng Liu <liucheng32@huawei.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reported-by: Fermín Serna <fermin@semmle.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Add support for capturing ethernet packets and storing
them in memory in PCAP(2.4) format, later to be analyzed by
any PCAP viewer software (IE. Wireshark)
This feature greatly assist debugging network issues such
as detecting dropped packets, packet corruption etc.
Signed-off-by: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Alex Marginean <alexm.osslist@gmail.com>
Tested-by: Alex Marginean <alexm.osslist@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
This file contains lots of internal details about the environment. Most
code can include env.h instead, calling the functions there as needed.
Rename this file and add a comment at the top to indicate its internal
nature.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
[trini: Fixup apalis-tk1.c]
Signed-off-by: Tom Rini <trini@konsulko.com>
This function fits better with the network subsystem, so move it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Joe Hershberger <joe.hershberger@ni.com>
Move env_set_hex() over to the new header file along with env_set_addr()
which uses it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
No mainline board enables CONFIG_MCAST_TFTP and there have been
compilation issues with the code for some time. Additionally, it has a
potential buffer underrun issue (reported as a side note in
CVE-2018-18439).
Remove the multicast TFTP code but keep the driver API for the future
addition of IPv6.
Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Signed-off-by: Chris Packham <judge.packham@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
When dealing with two ethernet ports and having "netretry" set
to "once", it could occur that the connection (e.g. an ARP
request) failed, hence the status of the netloop was
"NETLOOP_FAIL". Due to the setting of "netretry", the network
logic would then switch to the other network interface,
assigning "ret" with the return value of "net_start_again()".
If this call succeeded we would return 0 (i.e. success) to
the caller when in reality the network action failed.
Signed-off-by: Thomas RIENOESSL <thomas.rienoessl@bachmann.info>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Make it possible to add TCP versions of the same, while reusing
IP portions. This patch should not change any behavior.
Signed-off-by: Duncan Hare <DH@Synoia.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Peter originally sent a fix, but it breaks a number of other things.
This addresses the original reported issue in a different way.
That report was:
> U-Boot has 1 common buffer to send Ethernet frames, pointed to by
> net_tx_packet. When sending to an IP address without knowing the MAC
> address, U-Boot makes an ARP request (using the arp_tx_packet buffer)
> to find out the MAC address of the IP addressr. When a matching ARP
> reply is received, U-Boot continues sending the frame stored in the
> net_tx_packet buffer.
>
> However, in the mean time, if U-Boot needs to send out any network
> packets (e.g. replying ping packets or ARP requests for its own IP
> address etc.), it will use the net_tx_packet buffer to prepare the
> new packet. Thus this buffer is no longer the original packet meant
> to be transmitted after the ARP reply. The original packet will be
> lost.
This instead uses the ARP tx buffer to send async replies in the case
where we are actively waiting for an ARP reply.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reported-by: Tran Tien Dat <peter.trantiendat@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
The same basic parsing was implemented in tftp and nfs, so add a helper
function to do the work once.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Instead of depending on a env callback for bootfile, read it explicitly.
We do this because the bootfile can be specified on the command line and
if it is, we will overwrite the internal variable. If a netboot_common()
is called again with no bootfile parameter, we want to use the one in
the environment.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
With net autoload, we check the prerequisites for the initial command,
but the greater prerequisites when autoloading are not checked.
If we would attempt to autoload, check those prerequisites too.
If we are not expecting a serverip from the server, then don't worry
about it not being set, but don't attempt to load if it isn't.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
For net_boot_common, we allow the serverip to be specified as part of
the boot file name. For net commands that require serverip, include that
source as a valid specification of serverip.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
We can call commands like dhcp and bootp without arguments or with
explicit command line arguments that really should tell the code where
to look for files instead.
Unfortunately, the current code simply overwrites command line arguments
in the dhcp case with dhcp values.
This patch allows the code to preserve the command line values if they
were set on the command line. That way the semantics are slightly more
intuitive.
The reason this patch does that by introducing a new variable is that we
can not rely on net_boot_file_name[0] being unset, as today it's
completely legal to call "dhcp" and afterwards run "tftp" and expect the
latter to repeat the same query as before. I would prefer not to break
that behavior in case anyone relies on it.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Add a new command 'wol': Wait for an incoming Wake-on-LAN packet or
time out if no WoL packed is received.
If the WoL packet contains a password, it is saved in the environment
variable 'wolpassword' using the etherwake format (dot or colon
separated decimals).
Intended use case: a networked device should boot an alternate image.
It's attached to a network on a client site, modifying the DHCP server
configuration or setup of a tftp server is not allowed.
After power on the device waits a few seconds for a WoL packet. If a
packet is received, the device boots the alternate image. Otherwise
it boots the default image.
This method is a simple way to interact with a system via network even
if only the MAC address is known. Tools to send WoL packets are
available on all common platforms.
Some Ethernet drivers seem to pad the incoming packet. The additional
padding bytes might be recognized as Wake-on-LAN password bytes.
By default enabled in pengwyn_defconfig.
Signed-off-by: Lothar Felten <lothar.felten@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Global variable "net_state" is used in net_loop() state-machine.
But it happens that some times the net_loop() can be called
multiple times in the same call stack. For example when the
netconsole is enabled and we print the message while some other
net protocol is in action. Netconsole will overwrite the "net_state"
and that will break the logic for earlier started protocol.
To protect the state save and restore "net_state" variable each
time when we enter and exit net_loop().
Signed-off-by: Leonid Iziumtsev <leonid.iziumtsev@se.atlascopco.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
As part of the main conversion a few files were missed. These files had
additional whitespace after the '*' and before the SPDX tag and my
previous regex was too strict. This time I did a grep for all SPDX tags
and then filtered out anything that matched the correct styles.
Fixes: 83d290c56f ("SPDX: Convert all of our single license tags to Linux Kernel style")
Reported-by: Heinrich Schuchardt <xypron.debian@gmx.de>
Signed-off-by: Tom Rini <trini@konsulko.com>
We have a large number of places where while we historically referenced
gd in the code we no longer do, as well as cases where the code added
that line "just in case" during development and never dropped it.
Signed-off-by: Tom Rini <trini@konsulko.com>
The "net_try_count" counter starts from "1".
And the "retrycnt" contains requested amount of retries.
With current logic, that means that the actual retry amount
will be one time less then what we set in "netretry" env.
For example setting "netretry" to "once" will make "retrycnt"
equal "1", so no retries will be triggered at all.
Fix the logic by changing the statement of "if" condition.
Signed-off-by: Leonid Iziumtsev <leonid.iziumtsev@se.atlascopco.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
We are now using an env_ prefix for environment functions. Rename these
other functions as well, for consistency:
getenv_vlan()
getenv_bootm_size()
getenv_bootm_low()
getenv_bootm_mapsize()
env_get_default()
Suggested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
We are now using an env_ prefix for environment functions. Rename these
for consistency. Also add function comments in common.h.
Suggested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
We are now using an env_ prefix for environment functions. Rename these
two functions for consistency. Also add function comments in common.h.
Quite a few places use getenv() in a condition context, provoking a
warning from checkpatch. These are fixed up in this patch also.
Suggested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
We are now using an env_ prefix for environment functions. Rename these
commonly used functions, for consistency. Also add function comments in
common.h.
Suggested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
Move all of the status LED feature to drivers/led/Kconfig.
The LED status definitions were moved from the board configuration
files to the defconfig files.
TBD: Move all of the definitions in the include/status_led.h to the
relevant board's defconfig files.
Tested boards: CL-SOM-AM57x, CM-T335
Signed-off-by: Uri Mashiach <uri.mashiach@compulab.co.il>
At least on bfin, this "specimen" is actually allocated in the BSS and
wastes lots of memory in already tight memory conditions.
Also, with the introduction of NFSv3 support, this waste got
substantially larger.
Just remove it. If a board needs a specific different defragment size,
that board can override this setting.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
We can now successfully boot EFI applications from disk, but users
may want to also run them from a PXE setup.
This patch implements rudimentary network support, allowing a payload
to send and receive network packets.
With this patch, I was able to successfully run grub2 with network
access inside of QEMU's -M xlnx-ep108.
Signed-off-by: Alexander Graf <agraf@suse.de>
