CVE-2024-50073

tty: n_gsm: Fix use-after-free in gsm_cleanup_mux

Published Oct 29, 2024 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

tty: n_gsm: Fix use-after-free in gsm_cleanup_mux

BUG: KASAN: slab-use-after-free in gsm_cleanup_mux+0x77b/0x7b0
drivers/tty/n_gsm.c:3160 [n_gsm]
Read of size 8 at addr ffff88815fe99c00 by task poc/3379
CPU: 0 UID: 0 PID: 3379 Comm: poc Not tainted 6.11.0+ #56
Hardware name: VMware, Inc. VMware Virtual Platform/440BX
Desktop Reference Platform, BIOS 6.00 11/12/2020
Call Trace:
<TASK>
gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm]
__pfx_gsm_cleanup_mux+0x10/0x10 drivers/tty/n_gsm.c:3124 [n_gsm]
__pfx_sched_clock_cpu+0x10/0x10 kernel/sched/clock.c:389
update_load_avg+0x1c1/0x27b0 kernel/sched/fair.c:4500
__pfx_min_vruntime_cb_rotate+0x10/0x10 kernel/sched/fair.c:846
__rb_insert_augmented+0x492/0xbf0 lib/rbtree.c:161
gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm]
_raw_spin_lock_irqsave+0x92/0xf0 arch/x86/include/asm/atomic.h:107
__pfx_gsmld_ioctl+0x10/0x10 drivers/tty/n_gsm.c:3822 [n_gsm]
ktime_get+0x5e/0x140 kernel/time/timekeeping.c:195
ldsem_down_read+0x94/0x4e0 arch/x86/include/asm/atomic64_64.h:79
__pfx_ldsem_down_read+0x10/0x10 drivers/tty/tty_ldsem.c:338
__pfx_do_vfs_ioctl+0x10/0x10 fs/ioctl.c:805
tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818

Allocated by task 65:
gsm_data_alloc.constprop.0+0x27/0x190 drivers/tty/n_gsm.c:926 [n_gsm]
gsm_send+0x2c/0x580 drivers/tty/n_gsm.c:819 [n_gsm]
gsm1_receive+0x547/0xad0 drivers/tty/n_gsm.c:3038 [n_gsm]
gsmld_receive_buf+0x176/0x280 drivers/tty/n_gsm.c:3609 [n_gsm]
tty_ldisc_receive_buf+0x101/0x1e0 drivers/tty/tty_buffer.c:391
tty_port_default_receive_buf+0x61/0xa0 drivers/tty/tty_port.c:39
flush_to_ldisc+0x1b0/0x750 drivers/tty/tty_buffer.c:445
process_scheduled_works+0x2b0/0x10d0 kernel/workqueue.c:3229
worker_thread+0x3dc/0x950 kernel/workqueue.c:3391
kthread+0x2a3/0x370 kernel/kthread.c:389
ret_from_fork+0x2d/0x70 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:257

Freed by task 3367:
kfree+0x126/0x420 mm/slub.c:4580
gsm_cleanup_mux+0x36c/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm]
gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm]
tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818

[Analysis]
gsm_msg on the tx_ctrl_list or tx_data_list of gsm_mux
can be freed by multi threads through ioctl,which leads
to the occurrence of uaf. Protect it by gsm tx lock.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4008-1 linux-6.1 security update
Ubuntu USN Ubuntu USN USN-7276-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7277-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7310-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7383-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7383-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7384-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7384-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7385-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7386-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7403-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7451-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7468-1 Linux kernel (Azure, N-Series) vulnerabilities
Ubuntu USN Ubuntu USN USN-7523-1 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7524-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7683-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7683-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7683-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7684-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7684-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7684-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7685-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7685-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7685-3 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7685-4 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7685-5 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7686-1 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7701-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7701-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7701-3 Linux kernel (IoT) vulnerabilities
Ubuntu USN Ubuntu USN USN-7711-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7712-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7712-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7819-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7832-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7819-2 Linux kernel (Azure FIPS) vulnerabilities
History
Type Values Removed Values Added
Metrics epss

{'score': 0.00016}

epss

{'score': 0.00018}

Type Values Removed Values Added
Metrics epss

{'score': 0.00015}

epss

{'score': 0.00016}

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-416
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: tty: n_gsm: Fix use-after-free in gsm_cleanup_mux BUG: KASAN: slab-use-after-free in gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] Read of size 8 at addr ffff88815fe99c00 by task poc/3379 CPU: 0 UID: 0 PID: 3379 Comm: poc Not tainted 6.11.0+ #56 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 Call Trace: <TASK> gsm_cleanup_mux+0x77b/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] __pfx_gsm_cleanup_mux+0x10/0x10 drivers/tty/n_gsm.c:3124 [n_gsm] __pfx_sched_clock_cpu+0x10/0x10 kernel/sched/clock.c:389 update_load_avg+0x1c1/0x27b0 kernel/sched/fair.c:4500 __pfx_min_vruntime_cb_rotate+0x10/0x10 kernel/sched/fair.c:846 __rb_insert_augmented+0x492/0xbf0 lib/rbtree.c:161 gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] _raw_spin_lock_irqsave+0x92/0xf0 arch/x86/include/asm/atomic.h:107 __pfx_gsmld_ioctl+0x10/0x10 drivers/tty/n_gsm.c:3822 [n_gsm] ktime_get+0x5e/0x140 kernel/time/timekeeping.c:195 ldsem_down_read+0x94/0x4e0 arch/x86/include/asm/atomic64_64.h:79 __pfx_ldsem_down_read+0x10/0x10 drivers/tty/tty_ldsem.c:338 __pfx_do_vfs_ioctl+0x10/0x10 fs/ioctl.c:805 tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 Allocated by task 65: gsm_data_alloc.constprop.0+0x27/0x190 drivers/tty/n_gsm.c:926 [n_gsm] gsm_send+0x2c/0x580 drivers/tty/n_gsm.c:819 [n_gsm] gsm1_receive+0x547/0xad0 drivers/tty/n_gsm.c:3038 [n_gsm] gsmld_receive_buf+0x176/0x280 drivers/tty/n_gsm.c:3609 [n_gsm] tty_ldisc_receive_buf+0x101/0x1e0 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x61/0xa0 drivers/tty/tty_port.c:39 flush_to_ldisc+0x1b0/0x750 drivers/tty/tty_buffer.c:445 process_scheduled_works+0x2b0/0x10d0 kernel/workqueue.c:3229 worker_thread+0x3dc/0x950 kernel/workqueue.c:3391 kthread+0x2a3/0x370 kernel/kthread.c:389 ret_from_fork+0x2d/0x70 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:257 Freed by task 3367: kfree+0x126/0x420 mm/slub.c:4580 gsm_cleanup_mux+0x36c/0x7b0 drivers/tty/n_gsm.c:3160 [n_gsm] gsmld_ioctl+0x395/0x1450 drivers/tty/n_gsm.c:3408 [n_gsm] tty_ioctl+0x643/0x1100 drivers/tty/tty_io.c:2818 [Analysis] gsm_msg on the tx_ctrl_list or tx_data_list of gsm_mux can be freed by multi threads through ioctl,which leads to the occurrence of uaf. Protect it by gsm tx lock.
Title tty: n_gsm: Fix use-after-free in gsm_cleanup_mux
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Aug 5, 2026, 11:41 AM
Reserved
Oct 21, 2024, 7:36 PM
Status
Modified
Published
Oct 29, 2024, 1:15 AM
Modified
Jun 17, 2026, 8:03 AM
Severity
Moderate
Public date
Oct 29, 2024, 12:00 AM