high CVSS 7.8

CVE-2022-49474·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix dangling sco_conn and use-after-free in sco_sock_timeout Connecting the same socket twice consecutively in sco_sock_connect() could lead to a race condition where two sco_conn objects are created but only one is associated with the socket. If the socket is closed before the SCO connection is established, the timer associated with the dangling sco_conn object won't be canceled. As the sock object is being freed, the use-after-free problem happens when the timer callback function sco_sock_timeout() accesses the socket. Here's the call trace: dump_stack+0x107/0x163 ? refcount_inc+0x1c/ print_address_description.constprop.0+0x1c/0x47e ? refcount_inc+0x1c/0x7b kasan_report+0x13a/0x173 ? refcount_inc+0x1c/0x7b check_memory_region+0x132/0x139 refcount_inc+0x1c/0x7b sco_sock_timeout+0xb2/0x1ba process_one_work+0x739/0xbd1 ? cancel_delayed_work+0x13f/0x13f ? __raw_spin_lock_init+0xf0/0xf0 ? to_kthread+0x59/0x85 worker_thread+0x593/0x70e kthread+0x346/0x35a ? drain_workqueue+0x31a/0x31a ? kthread_bind+0x4b/0x4b ret_from_fork+0x1f/0x30

Severity
high
Software
Kernel
Fixed in
5.18.3
Published
2025-02-26

Affected versions

From: 5.18

Until: 5.18.3

Fixed in: 5.18.3

How to fix this CVE

Update your Linux kernel to version 5.18.3 or later to patch a use-after-free vulnerability in the Bluetooth SCO socket implementation. The issue occurs when consecutive socket connections create orphaned connection objects that trigger timer callbacks on freed memory. Apply the patch through your distribution's kernel update mechanism to eliminate the race condition.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check installed kernel version with `uname -r` and compare against 5.18.3 — versions 5.18.0 through 5.18.2 are vulnerable
  2. Step 2: Verify if Bluetooth kernel modules are loaded with `lsmod | grep bluetooth` — systems with SCO support are at risk if unpatched
  3. Step 3: Search kernel logs for use-after-free KASAN warnings with `dmesg | grep -i 'use-after-free\|refcount\|sco_sock'` to detect exploitation attempts
  4. Step 4: After patching, confirm the new kernel is running with `uname -r` and verify it reports version 5.18.3 or higher

FAQ

What is CVE-2022-49474?

This vulnerability is a use-after-free flaw in the Linux kernel's Bluetooth SCO (Synchronous Connection Oriented) socket handler. Rapid consecutive connection attempts can leave orphaned connection objects whose timer callbacks attempt to access freed socket memory, causing a kernel crash or potential privilege escalation.

Is CVE-2022-49474 being actively exploited?

No, this vulnerability is not documented as actively exploited in the wild or listed on CISA's Known Exploited Vulnerabilities catalog, though the local attack vector and high severity warrant prompt patching.

What versions of Kernel are affected by CVE-2022-49474?

Linux kernel versions 5.18.0 through 5.18.2 are vulnerable. Version 5.18.3 and all later stable releases contain the fix.

How do I check if my server is vulnerable to CVE-2022-49474?

Run `uname -r` to display your kernel version — if it shows 5.18.0, 5.18.1, or 5.18.2, your system is vulnerable. Otherwise, if it's 5.18.3 or higher (or a different kernel series), you are not affected.

Does Defensia detect CVE-2022-49474?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Linux kernel is installed on a monitored server, CVE-2022-49474 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2024-42256CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server re-repick on subrequest retry When a subrequest is marked for needing retry, netfs will call cifs_prepare_write() which will make cifs repick the server for the op before renegotiating credits; it then calls cifs_issue_write() which invokes smb2_async_writev() - which re-repicks the server. If a different server is then selected, this causes the increment of server->in_flight to happen against one record and the decrement to happen against another, leading to misaccounting. Fix this by just removing the repick code in smb2_async_writev(). As this is only called from netfslib-driven code, cifs_prepare_write() should always have been called first, and so server should never be NULL and the preparatory step is repeated in the event that we do a retry. The problem manifests as a warning looking something like: WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Which may be triggered by a number of different xfstests running against an Azure server in multichannel mode. generic/249 seems the most repeatable, but generic/215, generic/249 and generic/308 may also show it.
CVE-2024-36031CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: keys: Fix overwrite of key expiration on instantiation The expiry time of a key is unconditionally overwritten during instantiation, defaulting to turn it permanent. This causes a problem for DNS resolution as the expiration set by user-space is overwritten to TIME64_MAX, disabling further DNS updates. Fix this by restoring the condition that key_set_expiry is only called when the pre-parser sets a specific expiry.
CVE-2024-38612CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: fix invalid unregister error path The error path of seg6_init() is wrong in case CONFIG_IPV6_SEG6_LWTUNNEL is not defined. In that case if seg6_hmac_init() fails, the genl_unregister_family() isn't called. This issue exist since commit 46738b1317e1 ("ipv6: sr: add option to control lwtunnel support"), and commit 5559cea2d5aa ("ipv6: sr: fix possible use-after-free and null-ptr-deref") replaced unregister_pernet_subsys() with genl_unregister_family() in this error path.
CVE-2024-38623CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Use variable length array instead of fixed size Should fix smatch warning: ntfs_set_label() error: __builtin_memcpy() 'uni->name' too small (20 vs 256)
CVE-2021-47548CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ethernet: hisilicon: hns: hns_dsaf_misc: fix a possible array overflow in hns_dsaf_ge_srst_by_port() The if statement: if (port >= DSAF_GE_NUM) return; limits the value of port less than DSAF_GE_NUM (i.e., 8). However, if the value of port is 6 or 7, an array overflow could occur: port_rst_off = dsaf_dev->mac_cb[port]->port_rst_off; because the length of dsaf_dev->mac_cb is DSAF_MAX_PORT_NUM (i.e., 6). To fix this possible array overflow, we first check port and if it is greater than or equal to DSAF_MAX_PORT_NUM, the function returns.

References

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