CVE-2026-68086
UnknownSummary
A vulnerability in the Linux kernel's khugepaged mechanism can lead to data loss. Specifically, when a file is written, closed, then subjected to MADV_COLLAPSE, and later reopened for writing, dirty folios may be permanently discarded. The issue occurs when khugepaged interacts with previous writes, resulting in data loss.
Risk Assessment
Organizations may experience unexpected data loss in filesystems when using transparent huge pages (THP) and file write/read operations. A local attacker could potentially exploit this vulnerability to deliberately delete data, compromising data integrity.
Recommendation
Apply kernel patches that address this issue as soon as they are available. In the meantime, consider disabling khugepaged for filesystems where data loss risk is unacceptable.
Other vulnerabilities in Linux kernel
See all- CVE-2026-80577Unknown
In the Linux kernel's drm/panthor driver, panthor_fw_load_section_entry() skips BO creation for zero-sized firmware sections but adds them to the section list, leading to NULL pointer dereference in later paths. The fix skips adding such sections to the list.
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In the Linux kernel powerpc/pseries papr-phy-attest, missing validation of cmd.length could lead to buffer overflow. The fix adds length checks and fixes memory leaks on error paths.
- CVE-2026-80567Unknown
In the Linux kernel Synaptics RMI4 driver (F54), worker errors were not propagated to the V4L2 queue, causing stale or uninitialized data to be delivered to userspace. The fix adds error checking and marks buffers as error state.
- CVE-2026-80566Unknown
In the Linux kernel, the hynitron_cstxxx driver improperly validated touch count and finger IDs. This can lead to corrupted touch state or out-of-bounds buffer access.
- CVE-2026-80564Unknown
In the Linux kernel, the gve driver lacks an implementation of adjfine, leading to a NULL pointer dereference when triggered from userspace, e.g., via testptp.
- CVE-2026-80563Unknown
A use-after-free vulnerability was found in the Linux kernel's gpio-sloppy-logic-analyzer driver. The 'trigger' debugfs file lacked proper protection, allowing a write to freed memory during device unbind. The issue was fixed by using debugfs_create_file() instead of debugfs_create_file_unsafe().
- CVE-2026-80543Unknown
In the Linux kernel, the xcrb_msg_to_type6cprb_msgx() and xcrb_msg_to_type6_ep11cprb_msgx() functions for s390/zcrypt copy a user space message into a kernel buffer based on length, but further processing assumes 4-byte alignment. As a result, up to 3 bytes of uninitialized kernel memory are forwarded to further processing, potentially exposing kernel memory to the crypto card firmware.
- CVE-2026-80542Unknown
In the Linux kernel, the amdgpu driver for AMD Display has a NULL pointer dereference in amdgpu_dm_crtc_set_vblank() when vblank is enabled or queried before a stream is attached to acrtc_state->stream. This can lead to a system crash.
- CVE-2026-80535Unknown
In the Linux kernel XFS filesystem, during directory tree repair, a self-referential directory may be detected. In such a case, the repair code attempts to lock the same inode twice (double iolock/ilock), leading to a deadlock. The fix detects this corner case and handles it appropriately.
- CVE-2026-80533Unknown
In the Linux kernel XFS filesystem, during AGI repair, the function xrep_iunlink_walk_ondisk_bucket may attempt to use the pointer sc->sa.agi_bp, which can be null if the buffer verifier fails. The fix uses ragi->agi_bp instead, which skips verifier checks, to avoid walking off the end of memory.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: write all dirty file folios when collapsing [There is no upstream commit, as this code was removed by upstream commit 044925f9b565 ("mm: fs: remove filemap_nr_thps*() functions and their users")] As-is, khugepaged and writable-file opening exclude each other. A file cannot be open writeable and have THPs (because the filesystem is not aware of them). khugepaged will never collapse file pages for files that are opened writeable. On an open(O_RDWR/O_WRONLY), the page cache for that particular file is dropped. This is fine because nothing could've been dirtied. However, there is an edge-case: collapse_file() might not be able to coexist with concurrent writers, but it can coexist with dirty folios (from previous writers). Therefore, the following can happen: open(file, O_RDWR) write(file) close(file) madvise(file_mapping, MADV_COLLAPSE, some non-dirty range) open(file, O_RDWR) nr_thps > 0 truncate_inode_pages() /* THPs are cleared out, but so are the dirty folios */ When this edge-case happens, there is data loss, as the dirty folios are fully discarded. Fix it by fully writing back the page cache (and waiting) when collapsing file THPs. Doing so provides the guarantee that no dirty folio will be observed while there are active THPs. To fully ensure this is safe, the invalidate_lock needs to be held while doing the writeout, so that do_dentry_open()'s page cache truncation excludes this write-and-wait. As a side effect, move the nr_thps counter bumping outside the i_pages lock. This is correct since the counter itself is an atomic_t and the producer <-> consumer correctness is provided by a full memory barrier: smp_mb() in collapse_file()/memory barrier implied by full ordering in get_write_access() -> atomic_inc_unless_negative().