critical CVSS 9.8

CVE-2024-47408·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: net/smc: check smcd_v2_ext_offset when receiving proposal msg When receiving proposal msg in server, the field smcd_v2_ext_offset in proposal msg is from the remote client and can not be fully trusted. Once the value of smcd_v2_ext_offset exceed the max value, there has the chance to access wrong address, and crash may happen. This patch checks the value of smcd_v2_ext_offset before using it.

Severity
critical
Software
Kernel
Fixed in
6.12.7
Published
2025-01-11

Affected versions

From: 6.7

Until: 6.12.7

Fixed in: 6.12.7

How to fix this CVE

Update your Linux kernel to version 6.12.7 or later to patch the SMC (Shared Memory Communications) protocol validation flaw. This critical vulnerability allows remote attackers to trigger memory access violations through malicious proposal messages. Perform a kernel update immediately followed by a system reboot to ensure the fix is active.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Run 'uname -r' to check your current kernel version and compare against 6.12.7—if your version is between 6.7 and 6.12.6, you are vulnerable.
  2. Check if SMC protocol is enabled in your kernel with 'grep CONFIG_SMC /boot/config-$(uname -r)' and confirm it shows CONFIG_SMC=m or CONFIG_SMC=y.
  3. Monitor kernel logs with 'sudo journalctl -u kernel --no-pager | grep -i "smc\|smcd\|crash\|oops"' for any SMC-related memory faults or panics.
  4. After patching, verify the new kernel is active by running 'uname -r' and confirming the version is 6.12.7 or later.

FAQ

What is CVE-2024-47408?

This vulnerability exists in the Linux kernel's SMC protocol implementation where the smcd_v2_ext_offset field in proposal messages received from remote clients is not properly validated, potentially allowing memory access violations and system crashes when the offset exceeds safe bounds.

Is CVE-2024-47408 being actively exploited?

No, this vulnerability is not currently listed in CISA's Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available, though the critical CVSS score of 9.8 warrants immediate patching.

What versions of Kernel are affected by CVE-2024-47408?

Linux kernel versions 6.7 through 6.12.6 are affected; kernel 6.12.7 and later contain the fix.

How do I check if my server is vulnerable to CVE-2024-47408?

Run 'uname -r' and if the output shows a version between 6.7 and 6.12.6, your system is vulnerable; additionally confirm SMC is compiled in with 'grep CONFIG_SMC /boot/config-$(uname -r)'.

Does Defensia detect CVE-2024-47408?

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-2024-47408 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2026-100075CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: RDMA/srpt: Fix srpt_alloc_rw_ctxs() unwind counters When srpt_alloc_rw_ctxs() fails partway through a multi-buffer indirect descriptor, the unwind path destroys RDMA contexts but leaves stale n_rw_ctx and n_rdma values (and a dangling rw_ctxs pointer). Later sq_wr_avail accounting in srpt_queue_response() or srpt_write_pending() can then subtract the wrong number of send queue credits. Reset the counters and clear rw_ctxs after freeing the heap allocation before returning an error.
CVE-2026-64035CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: igc: set tx buffer type for SMD frames Sashiko pointed out that igc_fpe_init_smd_frame() initializes igc_tx_buffer fields for an SMD skb, but does not set the buffer type: https://sashiko.dev/#/patchset/20260415025226.114115-1-kohei%40enjuk.jp Since igc_tx_buffer entries are reused, a stale XDP or XSK type can remain and make TX completion use the wrong cleanup path. Set the buffer type to IGC_TX_BUFFER_TYPE_SKB.
CVE-2026-64033CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: RDMA/rtrs: Fix use-after-free in path file creation cleanup In the error path of rtrs_srv_create_path_files(), the sysfs root folders may already have been created and srv_path->kobj may already have been initialized. If a later step fails, the cleanup currently calls kobject_put(&srv_path->kobj) before rtrs_srv_destroy_once_sysfs_root_folders(srv_path). kobject_put() may drop the last reference to srv_path->kobj and invoke the release callback, rtrs_srv_release(), which frees srv_path. The following call to rtrs_srv_destroy_once_sysfs_root_folders(srv_path) then dereferences srv_path internally to access srv_path->srv, resulting in a use-after-free. This failure path is reached before rtrs_srv_create_path_files() returns success, so the successful-path lifetime handling is not involved. Fix this by destroying the sysfs root folders before calling kobject_put(&srv_path->kobj), so srv_path is still valid while the helper accesses it. This issue was found by a static analysis tool I am developing.
CVE-2026-64037CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mld: fix TSO segmentation explosion when AMSDU is disabled When the TLC notification disables AMSDU for a TID, the MLD driver sets max_tid_amsdu_len to the sentinel value 1. The TSO segmentation path in iwl_mld_tx_tso_segment() checks for zero but not for this sentinel, allowing it to reach the num_subframes calculation: num_subframes = (max_tid_amsdu_len + pad) / (subf_len + pad) = (1 + 2) / (1534 + 2) = 0 This zero propagates to iwl_tx_tso_segment() which sets: gso_size = num_subframes * mss = 0 Calling skb_gso_segment() with gso_size=0 creates over 32000 tiny segments from a single GSO skb. This floods the TX ring with ~1024 micro-frames (the rest are purged), creating a massive burst of TX completion events that can lead to memory corruption and a subsequent use-after-free in TCP's retransmit queue (refcount underflow in tcp_shifted_skb, NULL deref in tcp_rack_detect_loss). The MVM driver is immune because it checks mvmsta->amsdu_enabled before reaching the num_subframes calculation. The MLD driver has no equivalent bitmap check and relies solely on max_tid_amsdu_len, which does not catch the sentinel value. Fix this by detecting the sentinel value (max_tid_amsdu_len == 1) at the existing check and falling back to non-AMSDU TSO segmentation. Also add a WARN_ON_ONCE guard after the num_subframes division as defense-in-depth to catch any future code paths that produce zero through a different mechanism.
CVE-2026-64000CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: net: hsr: fix potential OOB access in supervision frame handling Ensure the entire TLV header is linearized before access by adding sizeof(struct hsr_sup_tlv) to the pskb_may_pull() calls. Without this, a truncated frame could cause an out-of-bounds access.

References

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