high CVSS 7

CVE-2023-52503·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: tee: amdtee: fix use-after-free vulnerability in amdtee_close_session There is a potential race condition in amdtee_close_session that may cause use-after-free in amdtee_open_session. For instance, if a session has refcount == 1, and one thread tries to free this session via: kref_put(&sess->refcount, destroy_session); the reference count will get decremented, and the next step would be to call destroy_session(). However, if in another thread, amdtee_open_session() is called before destroy_session() has completed execution, alloc_session() may return 'sess' that will be freed up later in destroy_session() leading to use-after-free in amdtee_open_session. To fix this issue, treat decrement of sess->refcount and removal of 'sess' from session list in destroy_session() as a critical section, so that it is executed atomically.

Severity
high
Software
Kernel
Fixed in
6.5.8
Published
2024-03-02

Affected versions

From: 6.2

Until: 6.5.8

Fixed in: 6.5.8

How to fix this CVE

Update your Linux kernel to version 6.5.8 or later to patch a race condition in AMD TEE session management that could lead to use-after-free memory corruption. Systems running kernel versions 6.2 through 6.5.7 should prioritize this update, as the vulnerability affects the trusted execution environment driver and requires local access to exploit.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Run 'uname -r' to check your current kernel version and confirm if it falls in the 6.2-6.5.7 range
  2. Run 'grep -i amdtee /proc/modules' to check if the AMD TEE driver is loaded on the system
  3. Monitor '/var/log/kern.log' (Linux) or 'journalctl -k' for kernel oops/panic messages containing 'use-after-free' or 'UAF' related to amdtee_open_session or amdtee_close_session
  4. After patching, verify with 'uname -r' that the new kernel version is 6.5.8 or later, then reboot if necessary

FAQ

What is CVE-2023-52503?

CVE-2023-52503 is a use-after-free vulnerability in the AMD Trusted Execution Environment (TEE) driver within the Linux kernel, caused by an unprotected race condition between session reference counting and session destruction that allows attackers with local access to cause memory corruption.

Is CVE-2023-52503 being actively exploited?

No, CVE-2023-52503 is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are currently available.

What versions of Kernel are affected by CVE-2023-52503?

Linux kernel versions 6.2 through 6.5.7 are affected; the vulnerability is resolved in kernel 6.5.8 and later.

How do I check if my server is vulnerable to CVE-2023-52503?

Run 'uname -r' to display your kernel version; if the output shows a version between 6.2 and 6.5.7 inclusive, your system is vulnerable if AMD TEE is in use.

Does Defensia detect CVE-2023-52503?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2023-52503 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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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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