high CVSS 7.8

CVE-2021-47614·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: RDMA/irdma: Fix a user-after-free in add_pble_prm When irdma_hmc_sd_one fails, 'chunk' is freed while its still on the PBLE info list. Add the chunk entry to the PBLE info list only after successful setting of the SD in irdma_hmc_sd_one.

Severity: high
Software: Kernel
Fixed in: 5.15.10
Published: 2024-06-19

Affected versions

From: 5.14

Until: 5.15.10

Fixed in: 5.15.10

How to fix this CVE

Update your Linux kernel to version 5.15.10 or later to patch a memory management vulnerability in the RDMA/irdma driver. This flaw can allow local attackers with low privileges to trigger a use-after-free condition, potentially leading to system crashes or privilege escalation. Systems running kernel versions 5.14 through 5.15.9 should prioritize this update.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

Step 1: Check your kernel version by running: uname -r. Vulnerable versions are 5.14.0 through 5.15.9.
Step 2: Verify if RDMA/irdma driver is loaded by running: lsmod | grep irdma. If output is empty, the driver is not active.
Step 3: Search kernel logs for memory errors or page faults related to irdma by running: sudo journalctl -xe | grep -i 'irdma\|use.after.free\|memory'.
Step 4: After patching, reboot and confirm the new kernel version with: uname -r. Ensure it is 5.15.10 or later.

FAQ

What is CVE-2021-47614?

CVE-2021-47614 is a use-after-free vulnerability in the Linux kernel's RDMA/irdma driver. During memory allocation for page-based list entries, if the SD (Scatter Descriptor) setup fails, the chunk structure is prematurely freed while still referenced in the PBLE list, enabling potential denial of service or code execution.

Is CVE-2021-47614 being actively exploited?

No. This vulnerability is not listed on CISA's Known Exploited Vulnerabilities (KEV) catalog, and no public exploits are currently available.

What versions of Kernel are affected by CVE-2021-47614?

Linux kernel versions 5.14 through 5.15.9 are vulnerable. The fix is included in kernel 5.15.10 and all later versions.

How do I check if my server is vulnerable to CVE-2021-47614?

Run 'uname -r' and compare your kernel version. If it shows 5.14.x through 5.15.9, you are vulnerable. Also verify irdma is loaded with 'lsmod | grep irdma'.

Does Defensia detect CVE-2021-47614?

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-2021-47614 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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