high CVSS 7.8

CVE-2024-50130·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: netfilter: bpf: must hold reference on net namespace BUG: KASAN: slab-use-after-free in __nf_unregister_net_hook+0x640/0x6b0 Read of size 8 at addr ffff8880106fe400 by task repro/72= bpf_nf_link_release+0xda/0x1e0 bpf_link_free+0x139/0x2d0 bpf_link_release+0x68/0x80 __fput+0x414/0xb60 Eric says: It seems that bpf was able to defer the __nf_unregister_net_hook() after exit()/close() time. Perhaps a netns reference is missing, because the netns has been dismantled/freed already. bpf_nf_link_attach() does : link->net = net; But I do not see a reference being taken on net. Add such a reference and release it after hook unreg. Note that I was unable to get syzbot reproducer to work, so I do not know if this resolves this splat.

Severity
high
Software
Kernel
Fixed in
6.11.6
Published
2024-11-05

Affected versions

From: 6.7

Until: 6.11.6

Fixed in: 6.11.6

How to fix this CVE

Update your Linux kernel to version 6.11.6 or later to resolve a use-after-free vulnerability in the netfilter BPF subsystem. This flaw allows improper memory access when BPF programs interact with network namespaces that have been deallocated. Kernel maintainers have backported the fix to stable branches; ensure your system receives the patched kernel image and reboot to activate the security update.

sudo dnf update kernel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Run 'uname -r' to retrieve your current kernel version and confirm it is earlier than 6.11.6
  2. Check if BPF netfilter hooks are loaded by running 'lsmod | grep -i nf_bpf' or examining /proc/modules for netfilter BPF modules
  3. Review kernel logs with 'sudo dmesg | grep -i "use-after-free\|kasan\|nf_unregister_net_hook"' to detect past exploitation attempts
  4. After patching, reboot the system and run 'uname -r' again to verify the kernel version is 6.11.6 or newer

FAQ

What is CVE-2024-50130?

CVE-2024-50130 is a use-after-free vulnerability in the Linux kernel's netfilter BPF subsystem where network namespace references are not properly retained, leading to memory corruption when BPF programs interact with deallocated namespaces.

Is CVE-2024-50130 being actively exploited?

No, CVE-2024-50130 is not listed on CISA's Known Exploited Vulnerabilities catalog and no public exploits are available. However, the high CVSS score of 7.8 indicates significant risk to local attackers with kernel access.

What versions of Kernel are affected by CVE-2024-50130?

Linux kernel versions 6.7 through 6.11.5 are vulnerable. The fix is available in kernel 6.11.6 and later stable releases.

How do I check if my server is vulnerable to CVE-2024-50130?

Run 'uname -r' and compare your kernel version against the affected range (6.7–6.11.5). If your version falls within this range, your system is vulnerable and requires a kernel update.

Does Defensia detect CVE-2024-50130?

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-2024-50130 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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