critical CVSS 9.1

CVE-2024-36896·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: USB: core: Fix access violation during port device removal Testing with KASAN and syzkaller revealed a bug in port.c:disable_store(): usb_hub_to_struct_hub() can return NULL if the hub that the port belongs to is concurrently removed, but the function does not check for this possibility before dereferencing the returned value. It turns out that the first dereference is unnecessary, since hub->intfdev is the parent of the port device, so it can be changed easily. Adding a check for hub == NULL prevents further problems. The same bug exists in the disable_show() routine, and it can be fixed the same way.

Severity
critical
Software
Kernel
Fixed in
6.8.10
Published
2024-05-30

Affected versions

From: 6.7

Until: 6.8.10

Fixed in: 6.8.10

How to fix this CVE

Update your Linux kernel to version 6.8.10 or later to patch a critical NULL pointer dereference vulnerability in USB port device handling. This vulnerability can be triggered during concurrent USB hub removal operations, leading to kernel crashes or potential privilege escalation. Apply the patch immediately to systems running kernels 6.7 through 6.8.9.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Check kernel version: uname -r — verify it is below 6.8.10; if between 6.7 and 6.8.9, the system is vulnerable
  2. Confirm USB subsystem is active: lsmod | grep usbcore — if loaded, the vulnerable code path is present
  3. Search kernel logs for crashes: dmesg | grep -E 'NULL|oops|BUG' — look for USB hub removal related panics
  4. After patching, verify fix: uname -r should show 6.8.10 or later; reboot if needed and re-run step 1

FAQ

What is CVE-2024-36896?

This CVE describes a null pointer dereference in the Linux kernel's USB port management code. When a USB hub is removed while port operations are ongoing, the kernel fails to validate a pointer before dereferencing it, causing a kernel panic or potential code execution.

Is CVE-2024-36896 being actively exploited?

No, there are no reports of active exploitation in the wild, and no public exploits are currently available. However, the critical CVSS score (9.1) and ease of triggering warrant immediate patching.

What versions of Kernel are affected by CVE-2024-36896?

Linux kernel versions 6.7 through 6.8.9 are vulnerable. Kernel 6.8.10 and later include the fix.

How do I check if my server is vulnerable to CVE-2024-36896?

Run 'uname -r' and check if the version falls between 6.7.0 and 6.8.9; if so, your system is vulnerable and requires immediate kernel update and reboot.

Does Defensia detect CVE-2024-36896?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2024-36896 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-2024-36031CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: keys: Fix overwrite of key expiration on instantiation The expiry time of a key is unconditionally overwritten during instantiation, defaulting to turn it permanent. This causes a problem for DNS resolution as the expiration set by user-space is overwritten to TIME64_MAX, disabling further DNS updates. Fix this by restoring the condition that key_set_expiry is only called when the pre-parser sets a specific expiry.
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-2024-38623CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Use variable length array instead of fixed size Should fix smatch warning: ntfs_set_label() error: __builtin_memcpy() 'uni->name' too small (20 vs 256)
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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