medium CVSS 5.5

CVE-2021-47373·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v3-its: Fix potential VPE leak on error In its_vpe_irq_domain_alloc, when its_vpe_init() returns an error, there is an off-by-one in the number of VPEs to be freed. Fix it by simply passing the number of VPEs allocated, which is the index of the loop iterating over the VPEs. [maz: fixed commit message]

Severity
medium
Software
Kernel
Fixed in
5.14.9
Published
2024-05-21

Affected versions

From: 5.11

Until: 5.14.9

Fixed in: 5.14.9

How to fix this CVE

Update your Linux kernel to version 5.14.9 or later to resolve a resource management flaw in the GIC-v3 interrupt controller subsystem. This vulnerability can cause a virtual processor element (VPE) to leak during error handling in the interrupt domain allocation routine, potentially leading to denial of service. Apply the patch immediately if your system is running kernel versions 5.11 through 5.14.8.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Run 'uname -r' to check your currently installed kernel version. If it is between 5.11 and 5.14.8, your system is vulnerable.
  2. Verify the interrupt controller module is loaded by running 'lsmod | grep gic' to confirm the gic_v3_its driver is in use on your ARM64 system.
  3. Check kernel logs for error messages containing 'its_vpe_irq_domain_alloc' or memory allocation failures by running 'dmesg | grep -i its'.
  4. After updating, reboot the system and run 'uname -r' again to confirm the kernel version is 5.14.9 or newer.

FAQ

What is CVE-2021-47373?

This vulnerability is an off-by-one error in the Linux kernel's GIC-v3 interrupt chip driver that causes virtual processor elements (VPEs) to leak during error handling in the interrupt request domain allocation function, potentially exhausting system resources.

Is CVE-2021-47373 being actively exploited?

No, this CVE is not listed in CISA's Known Exploited Vulnerabilities catalog and no public exploits are available. However, it remains a valid denial-of-service vector on affected ARM64 systems.

What versions of Kernel are affected by CVE-2021-47373?

Linux kernel versions 5.11 through 5.14.8 are affected. Version 5.14.9 and later contain the fix.

How do I check if my server is vulnerable to CVE-2021-47373?

Run 'uname -r' and compare your kernel version. If it reports a version between 5.11 and 5.14.8, your system is vulnerable. This primarily affects ARM64-based systems using GIC-v3 interrupt controllers.

Does Defensia detect CVE-2021-47373?

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-2021-47373 will appear in your dashboard with remediation steps.

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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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