CVE-2026-98226
Low risk· EPSS 6%Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
In the Linux kernel, a collision exists between the SWAP_USAGE_OFFLIST_BIT flag and the real swap usage counter. The flag is defined as bit 30, which on systems with 4 KiB pages collides with the usage count once it reaches 4 TiB. This can cause underreporting of swap usage, premature swapoff leading to lost pages, and corruption of the counter and plist.
Risk Assessment
On systems with large swap usage (4 TiB or more), data loss may occur due to premature swapoff, and internal kernel structures may be corrupted. Incorrect swap usage reporting can also lead to poor administrative decisions.
Recommendation
Update the Linux kernel to a version containing the fix that changes SWAP_USAGE_OFFLIST_BIT to be based on atomic_long_t. Monitor swap usage and avoid configurations with extremely large swap until patched.
Other vulnerabilities in Linux kernel
See all- CVE-2026-99216Unknown
In the Linux kernel, the Hyper-V (hv) driver incorrectly forces the VMBus connection state to DISCONNECTED before calling vmbus_disconnect(). As a result, vmbus_initiate_unload() does not unload the connection because it only acts when the state is CONNECTED, so the Hyper-V host may continue sending messages or posting VMBus interrupts.
- CVE-2026-99215Unknown
In the Linux kernel power supply subsystem, a use-after-free vulnerability exists. If a power supply is unregistered while its external_power_changed() callback is still running, the driver may free data that the callback is still accessing, leading to a kernel crash (NULL pointer dereference).
- CVE-2026-99214Unknown
In the Linux kernel, the drm/vc4 HDMI driver has an ordering issue with Packet RAM enabling. When audio is triggered by the HPD handler before video is restored, vc4_hdmi_write_infoframe() may attempt to store an infoframe while Packet RAM is disabled, causing a kernel warning (splat). The fix moves Packet RAM enable/disable into the Runtime PM hooks.
- CVE-2026-99213Unknown
In the Linux kernel vsock subsystem, the TCP_ESTABLISHED to TCP_CLOSING transition on OP_RST can race with the connect loop. Resetting a socket still present in connected_table can lead to memory corruption, including a double list add and a kernel BUG.
- CVE-2026-99212Unknown
In the Linux kernel net/rds module, rds_rdma_cm_event_handler_cmn() returns the result of rdma_resolve_route() directly to rdma_cm on RDMA_CM_EVENT_ADDR_RESOLVED. A synchronous failure causes the id ic->i_cm_id to be destroyed while RDS still owns it, leading to use of a freed id during connection shutdown.
- CVE-2026-99211Unknown
In the Linux kernel netlink subsystem, socket filters can use SKF_NET_OFF and SKF_LL_OFF to read relative to an skb's network and MAC headers. Netlink producers may reserve headroom without resetting those headers, allowing a receiving socket's filter to read data before the initialized message and disclose memory contents.
- CVE-2026-99210Unknown
In the Linux kernel accel/rocket driver, rocket_probe() stores the return value of rocket_device_init() in the file-scoped rdev pointer before checking whether it is an error pointer. On failure rdev remains an ERR_PTR, and a later probe can skip initialization and dereference the error pointer when reading rdev->num_cores.
- CVE-2026-99209Unknown
In the Linux kernel drm/xe driver, xe_evict_flags() reads tbo->resource->mem_type, but a BO can reach eviction with no ttm.resource, e.g. an imported dma-buf whose resource was freed during teardown. This causes a NULL pointer dereference and a kernel fault.
- CVE-2026-99208Unknown
In the Linux kernel drm/xe/oa driver, ttm_bo_type_kernel BOs are not guaranteed to be zeroed on allocation and may contain data from previously freed pages. Since the OA buffer is mmap'able by userspace, this can expose stale kernel memory contents.
- CVE-2026-99207Unknown
In the Linux kernel's scsi: target subsystem, target_do_delayed_work() acquired delayed_cmd_lock with a plain spin_lock() without disabling interrupts, while all other acquisition sites use spin_lock_irqsave(). Since commands can now complete in interrupt context (complete_type=1 with direct_compl_supp), this can cause a deadlock when a completion arrives on the same CPU where the work item holds the lock.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: mm, swap: fix SWAP_USAGE_OFFLIST_BIT collision with real usage count SWAP_USAGE_OFFLIST_BIT is embedded in the si->inuse_pages usage counter, and is meant to sit above any value that counter can reach. However, it is defined from BITS_PER_TYPE(atomic_t), so it is bit 30. On a system with 4 KiB pages the flag collides with the usage count once that count reaches 4 TiB. swap_usage_in_pages() masks bit 30 out, so whenever the real count has that bit set, every caller of it reads 4 TiB low: * /proc/swaps understates Used by 4 TiB. * A raw count of exactly 2^30 masks to zero, so try_to_unuse() takes its "if (!swap_usage_in_pages(si)) goto success;" early exit and swapoff tears the device down while pages are still swapped out. Nothing in the rest of swapoff aborts the teardown, so those pages are lost. Independently of swapoff, the collision also corrupts the counter and the plist. On a device in normal use, a free that leaves bit 30 set in the count makes swap_usage_sub() see the flag where there is only count, and call add_to_avail_list(). It clears the bit with fetch_and(~SWAP_USAGE_OFFLIST_BIT), leaving the stored count 4 TiB below the real one, and calls plist_add() on a device that is already listed, tripping the WARN_ON(!plist_node_empty(node)) in plist_add() and linking the node a second time. Change the definition of SWAP_USAGE_OFFLIST_BIT to be based on atomic_long_t instead. Note that the usage counter field itself is of this same type, so it is still a valid bit.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS