cbcvebase.
CVE-2023-52564
published 2024-03-02

CVE-2023-52564: In the Linux kernel, the following vulnerability has been resolved: Revert "tty: n_gsm: fix UAF in gsm_cleanup_mux" This reverts commit…

PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.24%
14.8th percentile
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: ? __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 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

21 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.64-1 (bookworm)linux 6.1.64-1 (bookworm)
linuxlinux
linuxlinux
linuxlinux>= 5.10.190 < 5.10.1985.10.198
linuxlinux>= 5.15.124 < 5.15.1345.15.134
linuxlinux>= 5138c228311a863c3cf937b94a3ab4c87f1f70c4 < a48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eba48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eb
linuxlinux>= 6.1.43 < 6.1.566.1.56
linuxlinux>= 6.4.8 < 6.56.5
linuxlinux>= 8fc0eabaa73bbd9bd705577071564616da5c8c61 < 6d5c8862932d31a810b6545f7d69ecc124402c6e6d5c8862932d31a810b6545f7d69ecc124402c6e
linuxlinux>= 9615ca54bc138e35353a001e8b5d4824dce72188 < c61d0b87a7028c2c10faffc524d748334c7b9827c61d0b87a7028c2c10faffc524d748334c7b9827
linuxlinux>= 9b9c8195f3f0d74a826077fc1c01b9ee74907239 < 2bff660e0ff349dee84dc4f6f6d10da4497f5b282bff660e0ff349dee84dc4f6f6d10da4497f5b28
linuxlinux>= 9b9c8195f3f0d74a826077fc1c01b9ee74907239 < 29346e217b8ab8a52889b88f00b268278d6b766829346e217b8ab8a52889b88f00b268278d6b7668
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.205-15.10.205-1
linuxlinux_kernel>= 0 < 6.1.64-16.1.64-1
linuxlinux_kernel>= 0 < 6.5.6-16.5.6-1
linuxlinux_kernel>= 0 < 6.5.6-16.5.6-1
linuxlinux_kernel>= 5.10.190 < 5.10.1985.10.198
linuxlinux_kernel>= 5.15.124 < 5.15.1345.15.134
linuxlinux_kernel>= 6.1.43 < 6.1.566.1.56
linuxlinux_kernel>= 6.5 < 6.5.66.5.6

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.