CVE-2026-99229
UnknownSummary
In the Linux kernel, a spin in io_cqring_wait_schedule() was fixed when IO_CHECK_CQ_OVERFLOW_BIT is set and the overflow list cannot be flushed. The task spins in the kernel and cannot be killed, e.g. with IORING_SETUP_CQE_MIXED or when the application moves the CQ head.
Risk Assessment
An application thread can hang in the kernel without being killable, even by SIGKILL, causing denial of service. It affects applications using io_uring.
Recommendation
Update the Linux kernel to a version containing the fix that returns to the application when the list cannot be flushed. Schedule updates for systems using io_uring.
Other vulnerabilities in Linux kernel
See all- CVE-2026-58942High
In do_fault_around of memory.c, there is a possible use after free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58847Unknown
In kvm_vfio_pviommu_attach of vfio.c, there is a possible double free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
- CVE-2026-58829High
In fuse_backing_mmap of backing.c, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58828High
In multiple functions of base.c, there is a possible use-after-free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58827High
In multiple functions of dma-buf.c, there is a possible use after free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58826High
In ksys_unshare of fork.c, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-58825High
In multiple functions of fork.c, there is a possible use after free due to a logic error in the code. This could lead to local escalation of privilege with no additional execution privileges needed.
- CVE-2026-99242Unknown
In the Linux kernel, a race between fallocate and mmap reads in NTFS was fixed. Fallocate only took invalidate_lock for punch hole, collapse range and insert range operations, and during standard allocation new clusters were mapped before being zeroed, allowing concurrent mmap page faults to read uninitialized disk data.
- CVE-2026-99241Unknown
In the Linux kernel, a missing lock in ntfs_filemap_page_mkwrite() was fixed; it called iomap_page_mkwrite() without holding mapping->invalidate_lock. A concurrent truncate or fallocate could be invalidating pagecache and rewriting the runlist while the write fault mapped blocks and dirtied the folio.
- CVE-2026-99240Unknown
In the Linux kernel, the DAMON subsystem (mm/damon/core) has a division-by-zero bug when a DAMOS quota goal has a target_value of zero. The fix moves handling of this corner case to the core layer by adding validation in damos_commit_quota_goal(), which now returns an error for zero target values.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: io_uring/wait: don't spin on a stuck overflow list As long as IO_CHECK_CQ_OVERFLOW_BIT is set, io_cqring_wait_schedule() returns right away, before it gets to look at signals or arms the timeout, for io_cqring_wait() to flush the overflow list. If that doesn't empty the list, and the CQ ring doesn't hold the number of events the caller wants, the loop starts over, with the same result. The task spins in the kernel, and can't be killed. The assumption is that this can't happen: if CQEs can't be flushed, the ring is full, and min_events is capped to the size of the ring. But: - With IORING_SETUP_CQE_MIXED a 32b CQE needs two contiguous entries. It is stuck on the list if a single one is free, and then the ring holds less than cq_entries events. A single threaded application that asks for as many events as the ring has entries never gets out of io_uring_enter(). - Whether the ring is full is up to the CQ head, which the application can write to. While one thread waits for events on an empty ring, another one can move the head back so that the ring looks full and have a CQE overflow. The waiter can't be stopped any more, not even by SIGKILL. Only the application can make room in the CQ ring. Return to it if the list could not be flushed.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS