ghsa-g7pr-gf5r-fx64
Vulnerability from github
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:
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().
{
"affected": [],
"aliases": [
"CVE-2023-52564"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-03-02T22:15:48Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"tty: n_gsm: fix UAF in gsm_cleanup_mux\"\n\nThis reverts commit 9b9c8195f3f0d74a826077fc1c01b9ee74907239.\n\nThe commit above is reverted as it did not solve the original issue.\n\ngsm_cleanup_mux() tries to free up the virtual ttys by calling\ngsm_dlci_release() for each available DLCI. There, dlci_put() is called to\ndecrease the reference counter for the DLCI via tty_port_put() which\nfinally calls gsm_dlci_free(). This already clears the pointer which is\nbeing checked in gsm_cleanup_mux() before calling gsm_dlci_release().\nTherefore, it is not necessary to clear this pointer in gsm_cleanup_mux()\nas done in the reverted commit. The commit introduces a null pointer\ndereference:\n \u003cTASK\u003e\n ? __die+0x1f/0x70\n ? page_fault_oops+0x156/0x420\n ? search_exception_tables+0x37/0x50\n ? fixup_exception+0x21/0x310\n ? exc_page_fault+0x69/0x150\n ? asm_exc_page_fault+0x26/0x30\n ? tty_port_put+0x19/0xa0\n gsmtty_cleanup+0x29/0x80 [n_gsm]\n release_one_tty+0x37/0xe0\n process_one_work+0x1e6/0x3e0\n worker_thread+0x4c/0x3d0\n ? __pfx_worker_thread+0x10/0x10\n kthread+0xe1/0x110\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x2f/0x50\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1b/0x30\n \u003c/TASK\u003e\n\nThe actual issue is that nothing guards dlci_put() from being called\nmultiple times while the tty driver was triggered but did not yet finished\ncalling gsm_dlci_free().",
"id": "GHSA-g7pr-gf5r-fx64",
"modified": "2024-05-01T18:30:35Z",
"published": "2024-03-03T00:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-52564"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/29346e217b8ab8a52889b88f00b268278d6b7668"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2bff660e0ff349dee84dc4f6f6d10da4497f5b28"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6d5c8862932d31a810b6545f7d69ecc124402c6e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c61d0b87a7028c2c10faffc524d748334c7b9827"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2024/04/11/11"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2024/04/11/9"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2024/04/12/1"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2024/04/12/2"
}
],
"schema_version": "1.4.0",
"severity": []
}