high CVSS 7.1

CVE-2024-26672·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix variable 'mca_funcs' dereferenced before NULL check in 'amdgpu_mca_smu_get_mca_entry()' Fixes the below: drivers/gpu/drm/amd/amdgpu/amdgpu_mca.c:377 amdgpu_mca_smu_get_mca_entry() warn: variable dereferenced before check 'mca_funcs' (see line 368) 357 int amdgpu_mca_smu_get_mca_entry(struct amdgpu_device *adev, enum amdgpu_mca_error_type type, 358 int idx, struct mca_bank_entry *entry) 359 { 360 const struct amdgpu_mca_smu_funcs *mca_funcs = adev->mca.mca_funcs; 361 int count; 362 363 switch (type) { 364 case AMDGPU_MCA_ERROR_TYPE_UE: 365 count = mca_funcs->max_ue_count; mca_funcs is dereferenced here. 366 break; 367 case AMDGPU_MCA_ERROR_TYPE_CE: 368 count = mca_funcs->max_ce_count; mca_funcs is dereferenced here. 369 break; 370 default: 371 return -EINVAL; 372 } 373 374 if (idx >= count) 375 return -EINVAL; 376 377 if (mca_funcs && mca_funcs->mca_get_mca_entry) ^^^^^^^^^ Checked too late!

Severity
high
Software
Kernel
Fixed in
6.7.4
Published
2024-04-02

Affected versions

Until: 6.7.4

Fixed in: 6.7.4

How to fix this CVE

Update your Linux kernel to version 6.7.4 or later to resolve a null pointer dereference vulnerability in the AMD GPU MCA (Machine Check Architecture) error handling code. This flaw could allow local users with kernel access to trigger a kernel crash or information disclosure through improper pointer validation in the amdgpu_mca_smu_get_mca_entry() function. Apply the update immediately to systems running vulnerable kernel versions.

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 | grep -oE '^[0-9]+\.[0-9]+\.[0-9]+' and confirm it is below 6.7.4
  2. Step 2: Verify AMD GPU drivers are loaded with: lsmod | grep amdgpu to determine if the vulnerable code path is active on your system
  3. Step 3: Search kernel logs for null pointer dereference errors related to amdgpu_mca: sudo grep -i 'amdgpu_mca\|NULL pointer\|mca_funcs' /var/log/kern.log or journalctl -k | grep -i amdgpu_mca
  4. Step 4: After applying the kernel update, verify with: uname -r and confirm the version is 6.7.4 or higher, then reboot to load the patched kernel

FAQ

What is CVE-2024-26672?

This vulnerability is a null pointer dereference in the AMD GPU MCA error handling subsystem of the Linux kernel where a function pointer is used before being validated as non-null, potentially allowing local attackers to crash the kernel or read sensitive memory.

Is CVE-2024-26672 being actively exploited?

No, this vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are known to be available.

What versions of Kernel are affected by CVE-2024-26672?

Linux kernel versions prior to 6.7.4 are affected. All kernels up to and including 6.7.3 contain this vulnerability in the AMD GPU MCA error handling code.

How do I check if my server is vulnerable to CVE-2024-26672?

Run: uname -r and check if the version is below 6.7.4. Additionally, verify AMD GPU support is compiled in with: grep -i CONFIG_DRM_AMDGPU /boot/config-$(uname -r)

Does Defensia detect CVE-2024-26672?

Yes — Defensia's CVE advisory scanner compares installed kernel package versions against the NVD database. If Linux kernel is installed on a monitored server, CVE-2024-26672 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-2026-64439CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: crypto: krb5 - filter out async aead implementations at alloc krb5_aead_encrypt(), krb5_aead_decrypt() in rfc3961_simplified.c and rfc8009_encrypt(), rfc8009_decrypt() in rfc8009_aes2.c set a NULL completion callback and treat any negative return from crypto_aead_{encrypt,decrypt}() as terminal, falling through to kfree_sensitive(buffer). When the encrypt_name resolves to an async AEAD instance the request returns -EINPROGRESS, the buffer is freed while the backend's worker still holds a pointer, and the worker dereferences the freed slab on completion. KASAN report under UML+SLUB with a synthetic async aead backend bound to krb5->encrypt_name: BUG: KASAN: slab-use-after-free in t5_stub_complete+0x7d/0xc7 The helpers were written synchronously, so filter the async instances out at allocation time instead of plumbing crypto_wait_req() through every call site. Reachable via net/rxrpc/rxgk.c, fs/afs/cm_security.c and net/ceph/crypto.c on systems with an async AEAD provider bound to the krb5 enctype name.
CVE-2026-64066CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: netfs: Fix netfs_read_to_pagecache() to pause on subreq failure Fix netfs_read_to_pagecache() so that it pauses the generation of new subrequests if an already-issued subrequest fails.
CVE-2026-64383CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time. Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.
CVE-2026-64067CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: netfs: Fix missing barriers when accessing stream->subrequests locklessly The list of subrequests attached to stream->subrequests is accessed without locks by netfs_collect_read_results() and netfs_collect_write_results(), and then they access subreq->flags without taking a barrier after getting the subreq pointer from the list. Relatedly, the functions that build the list don't use any sort of write barrier when constructing the list to make sure that the NETFS_SREQ_IN_PROGRESS flag is perceived to be set first if no lock is taken. Fix this by: (1) Add a new list_add_tail_release() function that uses a release barrier to set the pointer to the new member of the list. (2) Add a new list_first_entry_or_null_acquire() function that uses an acquire barrier to read the pointer to the first member in a list (or return NULL). (3) Use list_add_tail_release() when adding a subreq to ->subrequests. (4) Use list_first_entry_or_null_acquire() when initially accessing the front of the list (when an item is removed, the pointer to the new front iterm is obtained under the same lock).

References

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