CVE-2024-50257

Published Nov 9, 2024

Last updated 7 months ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: Fix use-after-free in get_info() ip6table_nat module unload has refcnt warning for UAF. call trace is: WARNING: CPU: 1 PID: 379 at kernel/module/main.c:853 module_put+0x6f/0x80 Modules linked in: ip6table_nat(-) CPU: 1 UID: 0 PID: 379 Comm: ip6tables Not tainted 6.12.0-rc4-00047-gc2ee9f594da8-dirty #205 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:module_put+0x6f/0x80 Call Trace: <TASK> get_info+0x128/0x180 do_ip6t_get_ctl+0x6a/0x430 nf_getsockopt+0x46/0x80 ipv6_getsockopt+0xb9/0x100 rawv6_getsockopt+0x42/0x190 do_sock_getsockopt+0xaa/0x180 __sys_getsockopt+0x70/0xc0 __x64_sys_getsockopt+0x20/0x30 do_syscall_64+0xa2/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Concurrent execution of module unload and get_info() trigered the warning. The root cause is as follows: cpu0 cpu1 module_exit //mod->state = MODULE_STATE_GOING ip6table_nat_exit xt_unregister_template kfree(t) //removed from templ_list getinfo() t = xt_find_table_lock list_for_each_entry(tmpl, &xt_templates[af]...) if (strcmp(tmpl->name, name)) continue; //table not found try_module_get list_for_each_entry(t, &xt_net->tables[af]...) return t; //not get refcnt module_put(t->me) //uaf unregister_pernet_subsys //remove table from xt_net list While xt_table module was going away and has been removed from xt_templates list, we couldnt get refcnt of xt_table->me. Check module in xt_net->tables list re-traversal to fix it.
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
7.8
Impact score
5.9
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-416
134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-416

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: coresight: tmc-etr: Fix race condition between sysfs and perf mode When trying to run perf and sysfs mode simultaneously, the WARN_ON() in tmc_etr_enable_hw() is triggered sometimes: WARNING: CPU: 42 PID: 3911571 at drivers/hwtracing/coresight/coresight-tmc-etr.c:1060 tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] [..snip..] Call trace: tmc_etr_enable_hw+0xc0/0xd8 [coresight_tmc] (P) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] (L) tmc_enable_etr_sink+0x11c/0x250 [coresight_tmc] coresight_enable_path+0x1c8/0x218 [coresight] coresight_enable_sysfs+0xa4/0x228 [coresight] enable_source_store+0x58/0xa8 [coresight] dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x120/0x1b8 vfs_write+0x2c8/0x388 ksys_write+0x74/0x108 __arm64_sys_write+0x24/0x38 el0_svc_common.constprop.0+0x64/0x148 do_el0_svc+0x24/0x38 el0_svc+0x3c/0x130 el0t_64_sync_handler+0xc8/0xd0 el0t_64_sync+0x1ac/0x1b0 ---[ end trace 0000000000000000 ]--- Since the enablement of sysfs mode is separeted into two critical regions, one for sysfs buffer allocation and another for hardware enablement, it's possible to race with the perf mode. Fix this by double check whether the perf mode's been used before enabling the hardware in sysfs mode. mode: [sysfs mode] [perf mode] tmc_etr_get_sysfs_buffer() spin_lock(&drvdata->spinlock) [sysfs buffer allocation] spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() drvdata->etr_buf = etr_perf->etr_buf spin_unlock(&drvdata->spinlock) spin_lock(&drvdata->spinlock) tmc_etr_enable_hw() WARN_ON(drvdata->etr_buf) // WARN sicne etr_buf initialized at the perf side spin_unlock(&drvdata->spinlock) With this fix, we retain the check for CS_MODE_PERF in get_etr_sysfs_buf. This ensures we verify whether the perf mode's already running before we actually allocate the buffer. Then we can save the time of allocating/freeing the sysfs buffer if race with the perf mode.CVE-2026-46272