high CVSS 7.1

CVE-2024-50227·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Fix KASAN reported stack out-of-bounds read in tb_retimer_scan() KASAN reported following issue: BUG: KASAN: stack-out-of-bounds in tb_retimer_scan+0xffe/0x1550 [thunderbolt] Read of size 4 at addr ffff88810111fc1c by task kworker/u56:0/11 CPU: 0 UID: 0 PID: 11 Comm: kworker/u56:0 Tainted: G U 6.11.0+ #1387 Tainted: [U]=USER Workqueue: thunderbolt0 tb_handle_hotplug [thunderbolt] Call Trace: <TASK> dump_stack_lvl+0x6c/0x90 print_report+0xd1/0x630 kasan_report+0xdb/0x110 __asan_report_load4_noabort+0x14/0x20 tb_retimer_scan+0xffe/0x1550 [thunderbolt] tb_scan_port+0xa6f/0x2060 [thunderbolt] tb_handle_hotplug+0x17b1/0x3080 [thunderbolt] process_one_work+0x626/0x1100 worker_thread+0x6c8/0xfa0 kthread+0x2c8/0x3a0 ret_from_fork+0x3a/0x80 ret_from_fork_asm+0x1a/0x30 This happens because the loop variable still gets incremented by one so max becomes 3 instead of 2, and this makes the second loop read past the the array declared on the stack. Fix this by assigning to max directly in the loop body.

Severity
high
Software
Kernel
Fixed in
6.11.7
Published
2024-11-09

Affected versions

From: 6.11

Until: 6.11.7

Fixed in: 6.11.7

How to fix this CVE

Update your Linux kernel to version 6.11.7 or later to resolve a memory safety issue in the Thunderbolt subsystem. This vulnerability affects kernel versions 6.11 through 6.11.6 and causes a stack buffer read vulnerability during Thunderbolt device enumeration. Apply the kernel update through your distribution's package manager and reboot to complete the remediation.

sudo dnf upgrade kernel kernel-headers kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check your current kernel version with: uname -r | awk -F. '{print $1"."$2"."$3}'
  2. Verify if Thunderbolt is enabled in your system: lsmod | grep thunderbolt (if output appears, Thunderbolt module is loaded)
  3. Search dmesg logs for KASAN warnings related to tb_retimer_scan: sudo dmesg | grep -i 'kasan\|tb_retimer_scan\|stack-out-of-bounds'
  4. Confirm the patch is applied by checking if kernel version is 6.11.7 or higher: uname -r

FAQ

What is CVE-2024-50227?

CVE-2024-50227 is a stack buffer over-read vulnerability in the Linux kernel's Thunderbolt driver subsystem. During Thunderbolt device enumeration, an improper loop variable increment causes the kernel to read beyond allocated stack memory, potentially leading to information disclosure or kernel panic.

Is CVE-2024-50227 being actively exploited?

No, CVE-2024-50227 is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are currently available. However, it remains a high-severity local vulnerability requiring prompt patching.

What versions of Kernel are affected by CVE-2024-50227?

Linux kernel versions 6.11 through 6.11.6 are affected. The vulnerability was resolved in kernel 6.11.7 and later.

How do I check if my server is vulnerable to CVE-2024-50227?

Run 'uname -r' to check your kernel version. If the output shows 6.11.x where x is less than 7 (e.g., 6.11.0 through 6.11.6), your system is vulnerable.

Does Defensia detect CVE-2024-50227?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server running version 6.11.0 through 6.11.6, CVE-2024-50227 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-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.

References

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