high CVSS 7.8

CVE-2024-26988·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: init/main.c: Fix potential static_command_line memory overflow We allocate memory of size 'xlen + strlen(boot_command_line) + 1' for static_command_line, but the strings copied into static_command_line are extra_command_line and command_line, rather than extra_command_line and boot_command_line. When strlen(command_line) > strlen(boot_command_line), static_command_line will overflow. This patch just recovers strlen(command_line) which was miss-consolidated with strlen(boot_command_line) in the commit f5c7310ac73e ("init/main: add checks for the return value of memblock_alloc*()")

Severity
high
Software
Kernel
Fixed in
6.8.8
Published
2024-05-01

Affected versions

From: 6.7

Until: 6.8.8

Fixed in: 6.8.8

How to fix this CVE

Update your Linux kernel to version 6.8.8 or later to resolve a memory buffer overflow vulnerability in the kernel's command-line initialization logic. This issue affects kernel versions 6.7 through 6.8.8 and can lead to kernel memory corruption during boot when certain command-line argument configurations are used. Prioritize this update for production systems to prevent potential denial of service or privilege escalation.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your current kernel version with `uname -r` and compare against the vulnerable range 6.7.x through 6.8.8
  2. Step 2: Verify if your kernel was compiled with the vulnerable init/main.c code by checking `cat /boot/config-$(uname -r) | grep CONFIG_CMDLINE` to see active boot parameters
  3. Step 3: Search system logs for kernel panics or memory corruption errors around boot time with `dmesg | grep -i overflow` or `journalctl -b | grep -i panic`
  4. Step 4: After updating, run `uname -r` to confirm the new kernel version is 6.8.8 or later, then reboot and verify the system boots without memory-related errors

FAQ

What is CVE-2024-26988?

CVE-2024-26988 is a memory buffer overflow vulnerability in the Linux kernel's initialization code where the static_command_line buffer is allocated with an incorrect size calculation, using strlen(boot_command_line) instead of strlen(command_line). When the command-line arguments are longer than expected, this causes a heap overflow that can corrupt kernel memory.

Is CVE-2024-26988 being actively exploited?

No, CVE-2024-26988 is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available at this time.

What versions of Kernel are affected by CVE-2024-26988?

Linux kernel versions from 6.7.0 through 6.8.8 are affected. The vulnerability was introduced in an earlier commit and propagated through these releases.

How do I check if my server is vulnerable to CVE-2024-26988?

Run `uname -r` to check your kernel version. If it shows 6.7.x or 6.8.x (with x less than 8), your system is vulnerable and requires an immediate update.

Does Defensia detect CVE-2024-26988?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2024-26988 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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-2026-100075CVSS 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-2026-64033CVSS 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-2026-64007CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: netfilter: synproxy: refresh tcphdr after skb_ensure_writable synproxy_tstamp_adjust() rewrites the TCP timestamp option in place and then patches the TCP checksum via inet_proto_csum_replace4() on the caller-supplied tcphdr pointer. Both ipv4_synproxy_hook() and ipv6_synproxy_hook() obtain that pointer with skb_header_pointer() before calling in, so it may either alias skb->head directly or point at the caller's on-stack _tcph buffer. Between obtaining the pointer and using it, the function calls skb_ensure_writable(skb, optend), which on a cloned or non-linear skb invokes pskb_expand_head() and frees the old skb->head. After that point the cached th is stale: caller (ipv[46]_synproxy_hook) th = skb_header_pointer(skb, ..., &_tcph) synproxy_tstamp_adjust(skb, protoff, th, ...) skb_ensure_writable(skb, optend) pskb_expand_head() /* kfree(old skb->head) */ ... inet_proto_csum_replace4(&th->check, ...) /* writes into freed head, or into the caller's stack copy leaving the on-wire checksum stale */ The option bytes are written through skb->data and are fine; only the checksum update goes through th and so lands in the wrong place. The result is either a write into freed slab memory or a packet leaving with a checksum that does not match its payload. Fix by re-deriving th from skb->data + protoff immediately after skb_ensure_writable() succeeds, so the subsequent checksum update targets the linear, writable header.
CVE-2026-64025CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: bpf, skmsg: fix verdict sk_data_ready racing with ktls rx sk_psock_strp_data_ready() already checks tls_sw_has_ctx_rx() and defers to psock->saved_data_ready when a TLS RX context is present, avoiding a conflict with the TLS strparser's ownership of the receive queue (commit e91de6afa81c, "bpf: Fix running sk_skb program types with ktls"). sk_psock_verdict_data_ready() has no equivalent guard. When a socket is inserted into a sockmap (BPF_SK_SKB_VERDICT) before TLS RX is configured, tls_sw_strparser_arm() saves sk_psock_verdict_data_ready as rx_ctx->saved_data_ready. On data arrival: tls_data_ready -> tls_strp_data_ready -> tls_rx_msg_ready -> saved_data_ready() = sk_psock_verdict_data_ready() -> tcp_read_skb() drains sk_receive_queue via __skb_unlink() without calling tcp_eat_skb(), so copied_seq is not advanced. tls_strp_msg_load() then finds tcp_inq() >= full_len (stale), calls tcp_recv_skb() on the now-empty queue, hits WARN_ON_ONCE(!first), and returns with rx_ctx->strp.anchor.frag_list pointing at a psock-owned (potentially freed) skb. tls_decrypt_sg() subsequently walks that frag_list: use-after-free. Apply the same fix as sk_psock_strp_data_ready(): if a TLS RX context is present, call psock->saved_data_ready (sock_def_readable) to wake recv() waiters and return immediately, leaving the receive queue untouched. TLS retains sole ownership of the queue and decrypts the record normally through tls_sw_recvmsg().

References

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