high CVSS 7.8

CVE-2023-52846·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: hsr: Prevent use after free in prp_create_tagged_frame() The prp_fill_rct() function can fail. In that situation, it frees the skb and returns NULL. Meanwhile on the success path, it returns the original skb. So it's straight forward to fix bug by using the returned value.

Severity
high
Software
Kernel
Fixed in
6.6.2
Published
2024-05-21

Affected versions

From: 6.6

Until: 6.6.2

Fixed in: 6.6.2

How to fix this CVE

Update your Linux kernel to version 6.6.2 or later to resolve this memory safety issue in the HSR/PRP (High-availability Seamless Redundancy) protocol handler. The vulnerability exists in the prp_create_tagged_frame() function where improper error handling can lead to use-after-free conditions. Prioritize this update for systems running kernel 6.6.0–6.6.2 that handle redundant network traffic.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your kernel version with `uname -r` and compare against affected range 6.6.0–6.6.2
  2. Step 2: Verify HSR/PRP module is loaded by running `lsmod | grep hsr` and `lsmod | grep prp`
  3. Step 3: Search kernel logs for memory corruption or oops messages related to prp_create_tagged_frame() using `dmesg | grep -i 'prp\|hsr\|use.after.free'`
  4. Step 4: After updating, confirm new kernel version with `uname -r` and verify it is 6.6.2 or later

FAQ

What is CVE-2023-52846?

This vulnerability is a use-after-free condition in the Linux kernel's HSR/PRP protocol implementation, specifically in the prp_create_tagged_frame() function. When the prp_fill_rct() helper function fails, it frees the network packet buffer (skb) but the calling code may still attempt to use the freed memory, leading to potential system crash or code execution.

Is CVE-2023-52846 being actively exploited?

No, this CVE is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploit code is currently available. However, the high CVSS score (7.8) reflects its potential impact and it should still be prioritized for patching.

What versions of Kernel are affected by CVE-2023-52846?

Linux kernel versions 6.6.0, 6.6.1, and 6.6.2 are affected. The vulnerability was introduced in kernel 6.6.0 and resolved in 6.6.3 and later stable releases.

How do I check if my server is vulnerable to CVE-2023-52846?

Run `uname -r` to display your kernel version. If it shows 6.6.0, 6.6.1, or 6.6.2, your system is vulnerable. You can also check `cat /proc/version` for additional kernel details.

Does Defensia detect CVE-2023-52846?

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-2023-52846 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-2024-39462CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: clk: bcm: dvp: Assign ->num before accessing ->hws Commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with __counted_by") annotated the hws member of 'struct clk_hw_onecell_data' with __counted_by, which informs the bounds sanitizer about the number of elements in hws, so that it can warn when hws is accessed out of bounds. As noted in that change, the __counted_by member must be initialized with the number of elements before the first array access happens, otherwise there will be a warning from each access prior to the initialization because the number of elements is zero. This occurs in clk_dvp_probe() due to ->num being assigned after ->hws has been accessed: UBSAN: array-index-out-of-bounds in drivers/clk/bcm/clk-bcm2711-dvp.c:59:2 index 0 is out of range for type 'struct clk_hw *[] __counted_by(num)' (aka 'struct clk_hw *[]') Move the ->num initialization to before the first access of ->hws, which clears up the warning.
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-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-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-2023-52846. Free for 1 server.

Get started free