high CVSS 7.8

CVE-2024-38577·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow There is a possibility of buffer overflow in show_rcu_tasks_trace_gp_kthread() if counters, passed to sprintf() are huge. Counter numbers, needed for this are unrealistically high, but buffer overflow is still possible. Use snprintf() with buffer size instead of sprintf(). Found by Linux Verification Center (linuxtesting.org) with SVACE.

Severity
high
Software
Kernel
Fixed in
6.9.3
Published
2024-06-19

Affected versions

From: 6.9

Until: 6.9.3

Fixed in: 6.9.3

How to fix this CVE

Update your Linux kernel to version 6.9.3 or later to resolve a buffer overflow vulnerability in the RCU tasks trace functionality. This vulnerability affects kernel versions 6.9 through 6.9.2 and could allow local privilege escalation under specific conditions. Apply the kernel update and reboot your system to ensure the fix is active.

sudo dnf update kernel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your kernel version: uname -r (vulnerable if output shows 6.9.0, 6.9.1, or 6.9.2)
  2. Verify the RCU tasks trace component is compiled in: grep CONFIG_TASKS_TRACE_RCU /boot/config-$(uname -r) (if output shows 'y', the component is active)
  3. Search system logs for memory-related errors: grep -i 'buffer\|overflow\|stack' /var/log/kern.log | head -20
  4. Confirm the fix by running: uname -r and verifying the version is 6.9.3 or newer after reboot

FAQ

What is CVE-2024-38577?

This is a buffer overflow vulnerability in the Linux kernel's RCU (Read-Copy-Update) tasks trace subsystem that occurs when displaying kernel thread status information. The vulnerability exists in the show_rcu_tasks_trace_gp_kthread() function where sprintf() could write beyond allocated buffer boundaries under certain counter conditions.

Is CVE-2024-38577 being actively exploited?

No, this vulnerability is not currently being actively exploited in the wild. However, it requires local access to trigger and could potentially lead to privilege escalation, so patching is still recommended.

What versions of Kernel are affected by CVE-2024-38577?

Linux kernel versions 6.9 through 6.9.2 are affected. The fix is included in kernel version 6.9.3 and all subsequent releases.

How do I check if my server is vulnerable to CVE-2024-38577?

Run 'uname -r' and check if your kernel version falls within 6.9.0-6.9.2. If it does and CONFIG_TASKS_TRACE_RCU is enabled (grep CONFIG_TASKS_TRACE_RCU /boot/config-$(uname -r)), your system is vulnerable.

Does Defensia detect CVE-2024-38577?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2024-38577 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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