high CVSS 7.8

CVE-2024-26723·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: lan966x: Fix crash when adding interface under a lag There is a crash when adding one of the lan966x interfaces under a lag interface. The issue can be reproduced like this: ip link add name bond0 type bond miimon 100 mode balance-xor ip link set dev eth0 master bond0 The reason is because when adding a interface under the lag it would go through all the ports and try to figure out which other ports are under that lag interface. And the issue is that lan966x can have ports that are NULL pointer as they are not probed. So then iterating over these ports it would just crash as they are NULL pointers. The fix consists in actually checking for NULL pointers before accessing something from the ports. Like we do in other places.

Severity
high
Software
Kernel
Fixed in
6.7.6
Published
2024-04-03

Affected versions

From: 6.7

Until: 6.7.6

Fixed in: 6.7.6

How to fix this CVE

Update your Linux kernel to version 6.7.6 or later to resolve a critical null pointer dereference that occurs when bonding LAN966x network interfaces. This patch adds proper null pointer validation during LAG (Link Aggregation Group) interface operations, preventing kernel crashes when configuring bonded connections. Apply the update immediately if you are running kernel versions 6.7 through 6.7.5 and use LAN966x network adapters.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your kernel version with: uname -r — vulnerable if output shows 6.7.0 through 6.7.5
  2. Verify if LAN966x drivers are loaded: lsmod | grep lan966x — if output is empty, this vulnerability does not apply to your system
  3. Test LAG bonding configuration on LAN966x interfaces with: ip link add name bond0 type bond miimon 100 mode balance-xor && ip link set dev eth0 master bond0 — if this command causes a kernel panic or system crash, the vulnerability is present
  4. After patching, confirm the new kernel version is active: uname -r — should show 6.7.6 or later

FAQ

What is CVE-2024-26723?

A null pointer dereference vulnerability in the Linux kernel's LAN966x network driver that crashes the system when attempting to add a network interface to a bonded LAG configuration. The driver fails to validate that all port structures are properly initialized before accessing them during LAG membership operations.

Is CVE-2024-26723 being actively exploited?

No, this vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available. However, it can be trivially triggered by any local user with network configuration privileges.

What versions of Kernel are affected by CVE-2024-26723?

Linux kernel versions 6.7.0 through 6.7.5 are vulnerable. Kernel 6.7.6 and all later versions include the fix.

How do I check if my server is vulnerable to CVE-2024-26723?

Run: uname -r && lsmod | grep lan966x — your system is vulnerable only if the kernel version is between 6.7.0-6.7.5 AND the lan966x module is loaded.

Does Defensia detect CVE-2024-26723?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2024-26723 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2024-42256CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server re-repick on subrequest retry When a subrequest is marked for needing retry, netfs will call cifs_prepare_write() which will make cifs repick the server for the op before renegotiating credits; it then calls cifs_issue_write() which invokes smb2_async_writev() - which re-repicks the server. If a different server is then selected, this causes the increment of server->in_flight to happen against one record and the decrement to happen against another, leading to misaccounting. Fix this by just removing the repick code in smb2_async_writev(). As this is only called from netfslib-driven code, cifs_prepare_write() should always have been called first, and so server should never be NULL and the preparatory step is repeated in the event that we do a retry. The problem manifests as a warning looking something like: WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Which may be triggered by a number of different xfstests running against an Azure server in multichannel mode. generic/249 seems the most repeatable, but generic/215, generic/249 and generic/308 may also show it.
CVE-2024-38541CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: of: module: add buffer overflow check in of_modalias() In of_modalias(), if the buffer happens to be too small even for the 1st snprintf() call, the len parameter will become negative and str parameter (if not NULL initially) will point beyond the buffer's end. Add the buffer overflow check after the 1st snprintf() call and fix such check after the strlen() call (accounting for the terminating NUL char).
CVE-2021-47548CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ethernet: hisilicon: hns: hns_dsaf_misc: fix a possible array overflow in hns_dsaf_ge_srst_by_port() The if statement: if (port >= DSAF_GE_NUM) return; limits the value of port less than DSAF_GE_NUM (i.e., 8). However, if the value of port is 6 or 7, an array overflow could occur: port_rst_off = dsaf_dev->mac_cb[port]->port_rst_off; because the length of dsaf_dev->mac_cb is DSAF_MAX_PORT_NUM (i.e., 6). To fix this possible array overflow, we first check port and if it is greater than or equal to DSAF_MAX_PORT_NUM, the function returns.
CVE-2024-38612CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: fix invalid unregister error path The error path of seg6_init() is wrong in case CONFIG_IPV6_SEG6_LWTUNNEL is not defined. In that case if seg6_hmac_init() fails, the genl_unregister_family() isn't called. This issue exist since commit 46738b1317e1 ("ipv6: sr: add option to control lwtunnel support"), and commit 5559cea2d5aa ("ipv6: sr: fix possible use-after-free and null-ptr-deref") replaced unregister_pernet_subsys() with genl_unregister_family() in this error path.
CVE-2022-48716CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ASoC: codecs: wcd938x: fix incorrect used of portid Mixer controls have the channel id in mixer->reg, which is not same as port id. port id should be derived from chan_info array. So fix this. Without this, its possible that we could corrupt struct wcd938x_sdw_priv by accessing port_map array out of range with channel id instead of port id.

References

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