high CVSS 7.8

CVE-2022-48874·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: Fix use-after-free and race in fastrpc_map_find Currently, there is a race window between the point when the mutex is unlocked in fastrpc_map_lookup and the reference count increasing (fastrpc_map_get) in fastrpc_map_find, which can also lead to use-after-free. So lets merge fastrpc_map_find into fastrpc_map_lookup which allows us to both protect the maps list by also taking the &fl->lock spinlock and the reference count, since the spinlock will be released only after. Add take_ref argument to make this suitable for all callers.

Severity
high
Software
Kernel
Fixed in
6.1.8
Published
2024-08-21

Affected versions

From: 5.18

Until: 6.1.8

Fixed in: 6.1.8

How to fix this CVE

Update your Linux kernel to version 6.1.8 or later to resolve a critical race condition in the fastrpc subsystem that allows local privilege escalation. This vulnerability affects kernel versions 5.18 through 6.1.7 and requires immediate patching on systems where untrusted local users have access. Apply the kernel update and reboot your system to complete remediation.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Check installed kernel version: uname -r — ensure version is 6.1.8 or later (not in range 5.18.0-6.1.7)
  2. Verify fastrpc module is loaded: lsmod | grep fastrpc — this indicates the vulnerable component is active
  3. Search system logs for use-after-free or kernel panic messages: grep -i 'use.after.free\|fastrpc\|general protection fault' /var/log/kern.log /var/log/messages
  4. Confirm kernel was built with fastrpc support: grep CONFIG_FASTRPC /boot/config-$(uname -r) — should return CONFIG_FASTRPC=m or =y

FAQ

What is CVE-2022-48874?

This vulnerability is a race condition in the Linux kernel's fastrpc (Fast RPC) subsystem that occurs when multiple threads access the same memory structure without proper synchronization, leading to use-after-free and potential local privilege escalation.

Is CVE-2022-48874 being actively exploited?

No, this vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog and no public exploits are currently available, though local attackers with system access could potentially leverage it.

What versions of Kernel are affected by CVE-2022-48874?

Linux kernel versions 5.18.0 through 6.1.7 are vulnerable. Version 6.1.8 and later include the fix.

How do I check if my server is vulnerable to CVE-2022-48874?

Run 'uname -r' to check your kernel version — if it reports between 5.18 and 6.1.7, your system is vulnerable. Confirm fastrpc is loaded with 'lsmod | grep fastrpc'.

Does Defensia detect CVE-2022-48874?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2022-48874 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

Track CVEs across your fleet automatically

Defensia scans your Linux servers and tells you exactly which ones are running vulnerable versions — including CVE-2022-48874. Free for 1 server.

Get started free