CVE-2023-52843
published 2024-05-21CVE-2023-52843: In the Linux kernel, the following vulnerability has been resolved: llc: verify mac len before reading mac header LLC reads the mac header with eth_hdr without…
PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.24%
15.8th percentile
In the Linux kernel, the following vulnerability has been resolved:
llc: verify mac len before reading mac header
LLC reads the mac header with eth_hdr without verifying that the skb
has an Ethernet header.
Syzbot was able to enter llc_rcv on a tun device. Tun can insert
packets without mac len and with user configurable skb->protocol
(passing a tun_pi header when not configuring IFF_NO_PI).
BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218
__netif_receive_skb_one_core net/core/dev.c:5523 [inline]
__netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637
netif_receive_skb_internal net/core/dev.c:5723 [inline]
netif_receive_skb+0x58/0x660 net/core/dev.c:5782
tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
tun_get_user+0x54c5/0x69c0 drivers/net/tun.c:2002
Add a mac_len test before all three eth_hdr(skb) calls under net/llc.
There are further uses in include/net/llc_pdu.h. All these are
protected by a test skb->protocol == ETH_P_802_2. Which does not
protect against this tun scenario.
But the mac_len test added in this patch in llc_fixup_skb will
indirectly protect those too. That is called from llc_rcv before any
other LLC code.
It is tempting to just add a blanket mac_len check in llc_rcv, but
not sure whether that could break valid LLC paths that do not assume
an Ethernet header. 802.2 LLC may be used on top of non-802.3
protocols in principle. The below referenced commit shows that used
to, on top of Token Ring.
At least one of the three eth_hdr uses goes back to before the start
of git history. But the one that syzbot exercises is introduced in
this commit. That commit is old enough (2008), that effectively all
stable kernels should receive this.
Affected
24 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.1.64-1 (bookworm) | linux 6.1.64-1 (bookworm) |
| linux | linux | — | — |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < 900a4418e3f66a32db6baaf23f92b99c20ae6535 | 900a4418e3f66a32db6baaf23f92b99c20ae6535 |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < 9a3f9054a5227d7567cba1fb821df48ccecad10c | 9a3f9054a5227d7567cba1fb821df48ccecad10c |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < cbdcdf42d15dac74c7287679fb2a9d955f8feb1f | cbdcdf42d15dac74c7287679fb2a9d955f8feb1f |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < 3a2653828ffc6101aef80bf58d5b77484239f779 | 3a2653828ffc6101aef80bf58d5b77484239f779 |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < 352887b3edd007cf9b0abc30fe9d98622acd859b | 352887b3edd007cf9b0abc30fe9d98622acd859b |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < f980e9a57dfb9530f1f4ee41a2420f2a256d7b29 | f980e9a57dfb9530f1f4ee41a2420f2a256d7b29 |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < 0a720d0259ad3521ec6c9e4199f9f6fc75bac77a | 0a720d0259ad3521ec6c9e4199f9f6fc75bac77a |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < ff5cb6a4f0c6d7fbdc84858323fb4b7af32cfd79 | ff5cb6a4f0c6d7fbdc84858323fb4b7af32cfd79 |
| linux | linux | >= f83f1768f833cb45bc93429fdc552252a4f55ac3 < 7b3ba18703a63f6fd487183b9262b08e5632da1b | 7b3ba18703a63f6fd487183b9262b08e5632da1b |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 5.10.205-1 | 5.10.205-1 |
| linux | linux_kernel | >= 0 < 6.1.64-1 | 6.1.64-1 |
| linux | linux_kernel | >= 0 < 6.6.8-1 | 6.6.8-1 |
| linux | linux_kernel | >= 0 < 6.6.8-1 | 6.6.8-1 |
| linux | linux_kernel | >= 2.6.26 < 4.14.330 | 4.14.330 |
| linux | linux_kernel | >= 4.15 < 4.19.299 | 4.19.299 |
| linux | linux_kernel | >= 4.20 < 5.4.261 | 5.4.261 |
| linux | linux_kernel | >= 5.11 < 5.15.139 | 5.15.139 |
| linux | linux_kernel | >= 5.16 < 6.1.63 | 6.1.63 |
| linux | linux_kernel | >= 5.5 < 5.10.201 | 5.10.201 |
| linux | linux_kernel | >= 6.2 < 6.5.12 | 6.5.12 |
| linux | linux_kernel | >= 6.6 < 6.6.2 | 6.6.2 |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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CISA ICS
Siemens SINEC OS
cisa_ics·2025-08-14
Siemens SINEC OS
ICS Advisory
##
Siemens SINEC OS
Release DateAugust 14, 2025
Alert CodeICSA-25-226-15
Related topics:
Industrial Control System Vulnerabilities, Industrial Control Systems
As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global).
View CSAF
## 1. EXECUTIVE SUMMARY
- CVSS v3.1 9.1
- ATTENTION: Exploitable remotely/low attack complexity
- Vendor: Siemens
- Equipment: RUGGEDCOM, SCALANCE
- Vulnerabilities: NULL Pointer Dereference, Use After Free, Unchecked Input for Loop Condition, Out-of-bounds Write, Ou
Red Hat
kernel: llc: verify mac len before reading mac header
vendor_redhat·2024-05-21·CVSS 5.5
CVE-2023-52843 [MEDIUM] CWE-20 kernel: llc: verify mac len before reading mac header
kernel: llc: verify mac len before reading mac header
In the Linux kernel, the following vulnerability has been resolved:
llc: verify mac len before reading mac header
LLC reads the mac header with eth_hdr without verifying that the skb
has an Ethernet header.
Syzbot was able to enter llc_rcv on a tun device. Tun can insert
packets without mac len and with user configurable skb->protocol
(passing a tun_pi header when not configuring IFF_NO_PI).
BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218
__netif_receive_s
Debian
CVE-2023-52843: linux - In the Linux kernel, the following vulnerability has been resolved: llc: verify...
vendor_debian·2023·CVSS 5.5
CVE-2023-52843 [MEDIUM] CVE-2023-52843: linux - In the Linux kernel, the following vulnerability has been resolved: llc: verify...
In the Linux kernel, the following vulnerability has been resolved: llc: verify mac len before reading mac header LLC reads the mac header with eth_hdr without verifying that the skb has an Ethernet header. Syzbot was able to enter llc_rcv on a tun device. Tun can insert packets without mac len and with user configurable skb->protocol (passing a tun_pi header when not configuring IFF_NO_PI). BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receiv
OSV
CVE-2023-52843: In the Linux kernel, the following vulnerability has been resolved: llc: verify mac len before reading mac header LLC reads the mac header with eth_hd
osv·2024-05-21·CVSS 5.5
CVE-2023-52843 [MEDIUM] CVE-2023-52843: In the Linux kernel, the following vulnerability has been resolved: llc: verify mac len before reading mac header LLC reads the mac header with eth_hd
In the Linux kernel, the following vulnerability has been resolved: llc: verify mac len before reading mac header LLC reads the mac header with eth_hdr without verifying that the skb has an Ethernet header. Syzbot was able to enter llc_rcv on a tun device. Tun can insert packets without mac len and with user configurable skb->protocol (passing a tun_pi header when not configuring IFF_NO_PI). BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receiv
GHSA
GHSA-jm7v-c85h-4vvr: In the Linux kernel, the following vulnerability has been resolved:
llc: verify mac len before reading mac header
LLC reads the mac header with eth_
ghsa_unreviewed·2024-05-21
CVE-2023-52843 [MEDIUM] CWE-908 GHSA-jm7v-c85h-4vvr: In the Linux kernel, the following vulnerability has been resolved:
llc: verify mac len before reading mac header
LLC reads the mac header with eth_
In the Linux kernel, the following vulnerability has been resolved:
llc: verify mac len before reading mac header
LLC reads the mac header with eth_hdr without verifying that the skb
has an Ethernet header.
Syzbot was able to enter llc_rcv on a tun device. Tun can insert
packets without mac len and with user configurable skb->protocol
(passing a tun_pi header when not configuring IFF_NO_PI).
BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline]
llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111
llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218
__netif_receive_skb_one_core net/core/dev.c:5523 [inline]
__netif_re
No detection rules found.
No public exploits indexed.
https://git.kernel.org/stable/c/0a720d0259ad3521ec6c9e4199f9f6fc75bac77ahttps://git.kernel.org/stable/c/352887b3edd007cf9b0abc30fe9d98622acd859bhttps://git.kernel.org/stable/c/3a2653828ffc6101aef80bf58d5b77484239f779https://git.kernel.org/stable/c/7b3ba18703a63f6fd487183b9262b08e5632da1bhttps://git.kernel.org/stable/c/900a4418e3f66a32db6baaf23f92b99c20ae6535https://git.kernel.org/stable/c/9a3f9054a5227d7567cba1fb821df48ccecad10chttps://git.kernel.org/stable/c/cbdcdf42d15dac74c7287679fb2a9d955f8feb1fhttps://git.kernel.org/stable/c/f980e9a57dfb9530f1f4ee41a2420f2a256d7b29https://git.kernel.org/stable/c/ff5cb6a4f0c6d7fbdc84858323fb4b7af32cfd79https://git.kernel.org/stable/c/0a720d0259ad3521ec6c9e4199f9f6fc75bac77ahttps://git.kernel.org/stable/c/352887b3edd007cf9b0abc30fe9d98622acd859bhttps://git.kernel.org/stable/c/3a2653828ffc6101aef80bf58d5b77484239f779https://git.kernel.org/stable/c/7b3ba18703a63f6fd487183b9262b08e5632da1bhttps://git.kernel.org/stable/c/900a4418e3f66a32db6baaf23f92b99c20ae6535https://git.kernel.org/stable/c/9a3f9054a5227d7567cba1fb821df48ccecad10chttps://git.kernel.org/stable/c/cbdcdf42d15dac74c7287679fb2a9d955f8feb1fhttps://git.kernel.org/stable/c/f980e9a57dfb9530f1f4ee41a2420f2a256d7b29https://git.kernel.org/stable/c/ff5cb6a4f0c6d7fbdc84858323fb4b7af32cfd79
2024-05-21
Published