Use After Free The advisory has been revoked - it doesn't affect any version of package kernel-modules-internal (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-RHEL8-KERNELMODULESINTERNAL-6390118
- published5 Mar 2024
- disclosed2 Mar 2024
Introduced: 2 Mar 2024
CVE-2023-52564 (opens in a new tab)Amendment
The Red Hat security team deemed this advisory irrelevant for RHEL:8.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-modules-internal package and not the kernel-modules-internal package as distributed by RHEL.
In the Linux kernel, the following vulnerability has been resolved:
Revert "tty: n_gsm: fix UAF in gsm_cleanup_mux"
This reverts commit 9b9c8195f3f0d74a826077fc1c01b9ee74907239.
The commit above is reverted as it did not solve the original issue.
gsm_cleanup_mux() tries to free up the virtual ttys by calling gsm_dlci_release() for each available DLCI. There, dlci_put() is called to decrease the reference counter for the DLCI via tty_port_put() which finally calls gsm_dlci_free(). This already clears the pointer which is being checked in gsm_cleanup_mux() before calling gsm_dlci_release(). Therefore, it is not necessary to clear this pointer in gsm_cleanup_mux() as done in the reverted commit. The commit introduces a null pointer dereference: <TASK> ? __die+0x1f/0x70 ? page_fault_oops+0x156/0x420 ? search_exception_tables+0x37/0x50 ? fixup_exception+0x21/0x310 ? exc_page_fault+0x69/0x150 ? asm_exc_page_fault+0x26/0x30 ? tty_port_put+0x19/0xa0 gsmtty_cleanup+0x29/0x80 [n_gsm] release_one_tty+0x37/0xe0 process_one_work+0x1e6/0x3e0 worker_thread+0x4c/0x3d0 ? __pfx_worker_thread+0x10/0x10 kthread+0xe1/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2f/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK>
The actual issue is that nothing guards dlci_put() from being called multiple times while the tty driver was triggered but did not yet finished calling gsm_dlci_free().
References
- https://access.redhat.com/security/cve/CVE-2023-52564
- http://www.openwall.com/lists/oss-security/2024/04/11/9
- http://www.openwall.com/lists/oss-security/2024/04/11/11
- http://www.openwall.com/lists/oss-security/2024/04/12/1
- http://www.openwall.com/lists/oss-security/2024/04/12/2
- https://git.kernel.org/stable/c/29346e217b8ab8a52889b88f00b268278d6b7668
- https://git.kernel.org/stable/c/2bff660e0ff349dee84dc4f6f6d10da4497f5b28
- https://git.kernel.org/stable/c/6d5c8862932d31a810b6545f7d69ecc124402c6e
- https://git.kernel.org/stable/c/a48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eb
- https://git.kernel.org/stable/c/c61d0b87a7028c2c10faffc524d748334c7b9827