Search Results (23566 CVEs found)

CVE Vendors Products Updated CVSS v3.1
CVE-2026-89759 1 Linux 1 Linux Kernel 2026-09-12 4.7 Medium
In the Linux kernel, the following vulnerability has been resolved: mm/kmemleak: avoid soft lockup when scanning task stacks Patch series "mm/kmemleak: avoid soft lockup when scanning task", v3. kmemleak_scan() scans every task stack under one rcu_read_lock() with no reschedule point, which can trip the soft lockup watchdog on hosts with very many threads. That prints the following message, depending on the workload+host configuration: watchdog: BUG: soft lockup - CPU#35 stuck for 22s! [kmemleak:537] scan_block kmemleak_scan kmemleak_scan_thread kthread Patch 1 walks the tasks with find_ge_pid() so the scan reschedules between tasks Patches 2-3 let the scan loops stop early once a scan is interrupted. This patch (of 3): kmemleak_scan() walks every thread and scans its kernel stack under a single rcu_read_lock() with no reschedule point. On a host with very many threads -- amplified by KASAN/lockdep in debug builds -- this loop can hog a CPU long enough to trip the soft lockup watchdog: watchdog: BUG: soft lockup - CPU#35 stuck for 22s! [kmemleak:537] scan_block kmemleak_scan kmemleak_scan_thread kthread A cond_resched() cannot be added directly: the loop runs inside an RCU read-side critical section. Walk the tasks one PID at a time with find_ge_pid(), taking the RCU read lock only to look up and pin each task. The stack is then scanned with no lock held, so cond_resched() runs between tasks and the scan stops early on scan_should_stop(). This follows the next_tgid()/task_seq_get_next() iteration pattern and keeps each RCU critical section short.
CVE-2026-89764 1 Linux 1 Linux Kernel 2026-09-12 5.3 Medium
In the Linux kernel, the following vulnerability has been resolved: rust: devres: fix race between concurrent revokers There is a potential race condition when two paths try to revoke a Devres concurrently. The driver core's devres_release_all() calls Revocable::revoke() via the release callback, while Devres::drop() calls revoke_nosync() on another CPU. The revoker that does not claim the is_available swap returns immediately, but the revoker that did may still be executing drop_in_place() on the inner data. This can cause a use-after-free when the other revoker's caller proceeds to drop adjacent resources that drop_in_place() still references (e.g., Devres<DmaMappedSgt> racing with SGTable freeing the backing sg_table and pages). Fix this by adding a Completion. The release callback signals the Completion after revoke() finishes, and Devres::drop() waits for it when it loses the is_available swap. This ensures the wrapped object is fully torn down before Devres::drop() returns.
CVE-2026-89594 1 Linux 1 Linux Kernel 2026-09-12 4.1 Medium
In the Linux kernel, the following vulnerability has been resolved: hsi: omap_ssi_core: fix missing DMA mask setup for SSI controller device The OMAP SSI driver uses a synthetic HSI controller device allocated via hsi_alloc_controller(), which does not go through the normal OF/platform device initialization path. As a result, the embedded struct device does not have a DMA mask initialized by default. After recent DMA API hardening changes, dma_map_sg() and related helpers now require a valid dma_mask to be present, otherwise the driver may crash or trigger warnings when attempting DMA mapping operations. Fix this by explicitly initializing the DMA mask for the SSI controller device and setting a 32-bit DMA mask, which matches the hardware capabilities.
CVE-2026-89607 1 Linux 1 Linux Kernel 2026-09-12 6.3 Medium
In the Linux kernel, the following vulnerability has been resolved: ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet parse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body without bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When encrypted_key_size > 64, decrypt_passphrase_encrypted_session_key() sets decrypted_key_size = encrypted_key_size and performs two out-of-bounds writes: 1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into decrypted_key[64] via scatterlist, overflowing into the parent ecryptfs_auth_tok struct. 2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes into crypt_stat->key[64], corrupting root_iv, keysig_list, and mutexes in ecryptfs_crypt_stat. Only AES-192 (cipher code 0x08) enables this because it sets crypt_stat->key_size = 24 independently of encrypted_key_size, allowing crypto_skcipher_setkey() to succeed while encrypted_key_size exceeds ECRYPTFS_MAX_KEY_BYTES. The PKI decryption path (parse_tag_65_packet) already validates decrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path omits this check. Bound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also protects the 512-byte encrypted_key[] buffer, so the former 512-byte check is removed as redundant. [tyhicks: Adjust the code comment to refer to macros representing the buffer sizes rather than mentioning the buffer size values since they may change in the future]
CVE-2026-89656 1 Linux 1 Linux Kernel 2026-09-12 5.9 Medium
In the Linux kernel, the following vulnerability has been resolved: libceph: reject buckets with mismatched CRUSH ids crush_decode() stores bucket data by array slot, and the mapper later derives the per-bucket workspace index from the decoded bucket id. A malformed map can therefore make one bucket reuse another bucket's workspace by encoding an id different from -1 - slot. For uniform buckets, the second replica selection expands the source bucket's permutation into that aliased workspace buffer. If the source bucket is larger than the aliased bucket, the write runs past the smaller permutation array and can escape the kvmalloc'd CRUSH workspace. KASAN reports a slab OOB write of 4 bytes in bucket_perm_choose(). Reject buckets whose encoded id does not match their array slot. Valid CRUSH maps already use the canonical negative id corresponding to the bucket slot, so this restores the invariant expected by work->work[-1 - in->id] without changing valid map behavior.
CVE-2026-89674 1 Linux 1 Linux Kernel 2026-09-12 7.5 High
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix XDR length calculation in nfsd4_ff_encode_layoutget The XDR buffer size calculation in nfsd4_ff_encode_layoutget() has multiple errors that can result in either an out-of-bounds write or leaking uninitialized kernel memory to the client: - fh_len doesn't account for XDR padding on the file handle data - uid and gid lengths use "8 + len" but xdr_encode_opaque() actually writes "4 + xdr_align_size(len)" bytes - ds_len omits the flags and stats_collect_hint fields (8 bytes), while len's header constant overestimates by 8 bytes -- these partially cancel but leave a net mismatch The worst case occurs with short strings (e.g. uid=0, gid=0 with an odd-sized file handle), where the function writes up to 5 bytes past the reserved XDR buffer. Conversely, when string lengths happen to be 4-byte aligned, the reservation is too large and stale buffer content is sent to the client. Fix this by breaking out every encoded field explicitly in the ds_len calculation, using xdr_align_size() for all variable-length opaque fields, and correcting the header constants.
CVE-2026-89681 1 Linux 1 Linux Kernel 2026-09-12 5.3 Medium
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix layout fence worker double-reference race The workqueue core clears WORK_STRUCT_PENDING before the callback is invoked, so delayed_work_pending() in lm_breaker_timedout() can return false while the fence worker is already running. This lets the breaker take a duplicate sc_count reference and schedule a new worker that coalesces with the in-progress one. The extra reference is never put, leaking the layout stateid. Replace the racy delayed_work_pending() check with an ls_fence_inflight boolean set atomically with refcount_inc_not_zero() under ls_lock, and cleared under ls_lock before the final nfs4_put_stid() on the dispose path; the retry path intentionally retains it. Remove the self-rearm mod_delayed_work() at the top of the worker.
CVE-2026-89539 1 Linux 1 Linux Kernel 2026-09-12 N/A
In the Linux kernel, the following vulnerability has been resolved: SUNRPC: reject duplicate CREDS_VALUE options gssx_dec_option_array() walks the wire-supplied option array and, for every entry whose name matches CREDS_VALUE, calls gssx_dec_linux_creds() on the same struct svc_cred. That helper unconditionally installs a fresh groups_alloc() result into creds->cr_group_info without releasing whatever pointer was already there: for (i = 0; i < count; i++) { ... decode name ... if (length == sizeof(CREDS_VALUE) && memcmp(p, CREDS_VALUE, sizeof(CREDS_VALUE)) == 0) { err = gssx_dec_linux_creds(xdr, creds); ... } } A reply that carries two CREDS_VALUE entries therefore overwrites cr_group_info on the second iteration and orphans the group_info allocated by the first call. The earlier free_creds path only releases the last cr_group_info via free_svc_cred(), so the first allocation's refcount stays at one and its kvmalloc-backed storage is leaked. No in-tree caller of gssp_accept_sec_context_upcall() expects more than one CREDS_VALUE per reply. Fix by tracking whether a CREDS_VALUE option has already been decoded and returning -EINVAL on any subsequent match, so the free_creds path releases the single group_info that was installed.
CVE-2026-89549 1 Linux 1 Linux Kernel 2026-09-12 5.9 Medium
In the Linux kernel, the following vulnerability has been resolved: sunrpc: route to a populated pool in svc_pool_for_cpu() svc_set_num_threads() spreads the requested threads evenly across the service's pools (base = nrservs / sv_nrpools). When a service runs fewer threads than it has pools -- e.g. an nfsd configured with fewer threads than the host has NUMA nodes while running in "pernode" or "percpu" mode -- the trailing pools are left with no threads at all. svc_xprt_enqueue() selects a pool from the CPU servicing the transport, queues the transport on that pool's sp_xprts, and only wakes a thread from the same pool. Each thread services exclusively its own pool, so a transport that lands on a threadless pool is enqueued on sp_xprts and never picked up: the connection hangs indefinitely. Have svc_pool_for_cpu() skip pools that currently have no threads, falling back to the next populated pool. This trades NUMA locality for a guarantee that the work is actually serviced. sp_nrthreads is only updated under the service mutex; the lockless read here is a best-effort routing hint, so annotate it with data_race().
CVE-2026-80788 1 Linux 1 Linux Kernel 2026-09-12 6.2 Medium
In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: Do not WARN on remotely-controlled oversized SGL allocations When fuzzing the nvme target code, I tripped a kernel warning in nvmet_tcp_map_data() because the length passed into the allocator is controlled by the remote initiator. A remote initiator that sends a command with an SGL claiming a huge number, can create a scatterlist and iovec allocation of over 1 million entries, which causes the backing kmalloc call to exceed MAX_PAGE_ORDER and then the page allocator will trip on a WARN_ON_ONCE_GFP() message: WARNING: mm/page_alloc.c:5280 __alloc_frozen_pages_noprof Workqueue: nvmet_tcp_wq nvmet_tcp_io_work ... sgl_alloc_order nvmet_tcp_map_data nvmet_tcp_try_recv_pdu As it's never good to trip a kernel warning remotely due to many systems having panic-on-warn enabled, let's silence it by just add GFP_NOWARN to the allocation flags.
CVE-2026-89773 1 Linux 1 Linux Kernel 2026-09-11 5.5 Medium
In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Skip Update HDCP Config In Transition State Transition state does not have a valid dm_stream_ctx that should skip configuring HDCP routine. The routine is valid to go through only when a valid stream is created.
CVE-2026-89772 1 Linux 1 Linux Kernel 2026-09-11 6.3 Medium
In the Linux kernel, the following vulnerability has been resolved: btrfs: write-protect folios during data writeback commit 095be159f3eb ("btrfs: unify folio dirty flag clearing") replaced the folio_clear_dirty_for_io() call in extent_write_cache_pages() with a plain folio_test_dirty() check. Besides clearing the dirty flag, folio_clear_dirty_for_io() also calls folio_mkclean(), which write-protects the shared mmap PTEs mapping the folio. Note that we still do call folio_clear_dirty_for_io() later in submit_one_sector() when we clear dirty on the last sector of the folio (the only sector for non-subpage cases). But we lost this early call in extent_write_cache_pages(). Without the extra write-protection, a process with the file mmap-ed can modify a sector while it is being used by writeback in a way that expects a stable folio (checksumming, compressing, copying, etc...) without faulting, which manifests as a handful of concrete bugs. 1. For large folios or subpage sectorsize, it is possible to submit a bio which does not cover the whole folio. When this happens, we will have a bio in flight for a folio that we have *not* called folio_clear_dirty_for_io() on. If a task with an existing mmap-ed PTE writes (without faulting..) in this window, it can result in corruptions. If the write arrives while the checksumming or writing itself is underway, this can result in an invalid checksum and later corruption reports on read. If the write arrives after checksumming/writing is done but before the last sector dirty is cleared, then the write is present in page cache but doesn't affect the dirty tracking and will be lost when the folio is fully finished being submitted and the dirty bit is cleared. This results in losing the write even if fsync() is called. 2. For zoned submissions which are done in batch separate from the main extent_writepage() loop, we also risk csum violations for those submissions. Zoned writes are clamped to max_zone_append_size and are not aligned with folios, so a submission can span two folios. The first folio being processed in extent_write_cache_pages() will call extent_write_locked_range() which will submit the partial range of the next folio, while the rest of that folio could still be dirty. So clearing dirty on the submitted sectors doesn't call folio_clear_dirty_for_io() and we have the same issue. Since extent_write_cache_pages() skips these batch submitted folios (they are already marked for writeback from submission by the preceding folio), we must add the extra write protection in lock_delalloc_folios(). 3. For inline extents this will subtly risk losing writes that happen after/while we copy the inline extent but before we clear dirty on the folio. 4. For folios spanning EOF, mmap could tamper with the zeroed bytes past EOF and cause them to be persisted where future faults would improperly see them instead of zeros. 5. Finally, for compressed extents, we risk modifying the folios while we work on compressing them which will result in corrupted compressed data. Specifically, in run_delalloc_compressed() we queue up work to do compress_file_range() in BTRFS_COMPRESSION_CHUNK_SIZE (512K) chunks which will call btrfs_folio_clamp_clear_dirty() on the range. For non-subpage, this will always clear the whole folio, safely. For subpage, we risk a partial clear here as well. In particular, imagine a 2M folio broken up into 512K chunks of work which might start compression work on one chunk before all the chunks compress_file_range() workers have gotten far enough to finish clearing all the dirty bitmaps of the folio and getting to folio_clear_dirty_for_io(). Large folios on the edges of submission ranges are similarly at risk to be only partly cleared. This particular gap was introduced by a second patch in the same series: commit a4ef54dbb576 ("btrfs: make extent_range_clear_dirty_for_io() to handle sector size < page size cases") We cannot simply restore the call to folio_clear ---truncated---
CVE-2026-89771 1 Linux 1 Linux Kernel 2026-09-11 4.7 Medium
In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix subbuf resize race with ring buffer readers trace_buffer subbuf_size is read lockless in ring_buffer_read_page() and ring_buffer_read_start(), while it can simultaneously be resized with ring_buffer_subbuf_order_set(). Instead of trace_buffer::subbuf_size, use bpage::order in ring_buffer_read_start() and ring_buffer_read_page(). In ring_buffer_read_start(), even with resize_disabled, there is still a possibility of a race with a buffer modification. Hold the trace_buffer mutex to synchronise with any pending ring buffer order modification. trace_buffer::subbuf_size is now actually useless, remove it. Also, create accessors rb_subbuf_capacity() and rb_page_capacity() which return the actual size available for storing events, while rb_subbuf_size() returns the actual subbuf page-size.
CVE-2026-89769 1 Linux 1 Linux Kernel 2026-09-11 7.5 High
In the Linux kernel, the following vulnerability has been resolved: clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path When cpuhp_setup_state fails after pit_clockevent_per_cpu_init has successfully called request_irq, the error handling jumps directly to out_pit_clocksource_unregister without freeing the registered IRQ. This leaks the IRQ line and, since kfree(pit) follows, leaves a dangling pointer registered as the interrupt handler's dev_id, potentially leading to a use-after-free if the IRQ fires afterwards. Fix it by calling pit_clockevent_per_cpu_exit to properly release the IRQ before falling through to the existing cleanup chain.
CVE-2026-89768 1 Linux 1 Linux Kernel 2026-09-11 2.3 Low
In the Linux kernel, the following vulnerability has been resolved: fs: fix user path of nested backing files backing_file_open() derives the path to be stored in the new backing file from user_file->f_path. This is incorrect when user_file itself is a backing file, which is the case for nested stacking filesystems, e.g. overlayfs mounts where the lowerdir of one overlayfs is the merged directory of another. Since commit def3ae83da02 ("fs: store real path instead of fake path in backing file f_path") the f_path of a backing file holds the real path of the intermediate layer, not the path that the user opened. Commit 924577e4f6ca ("ovl: Fix nested backing file paths") fixed this for such configurations by passing file_user_path() from ovl_open_realfile(). However, commit 6af36aeb147a ("lsm: add backing_file LSM hooks") changed the first argument of backing_file_open() from the user path back to the user file and derived the path from user_file->f_path again, silently re-introducing the problem. As a result, files mapped through a nested overlayfs show the wrong path in /proc/<pid>/maps and in perf/ftrace mmap records. For example, with two nested overlayfs mounts: mkdir -p /ovl/{lower,upper,work,merged} /ovl/nested echo hello > /ovl/lower/foo mount -t overlay overlay \ -o lowerdir=/ovl/lower,upperdir=/ovl/upper,workdir=/ovl/work \ /ovl/merged # at least two lowerdirs are needed when upperdir is nonexistent mount -t overlay overlay \ -o lowerdir=/ovl/merged:/ovl/lower /ovl/nested mapping /ovl/nested/foo shows a disconnected path instead of the user path: # readlink /proc/self/fd/3 /ovl/nested/foo # grep foo /proc/self/maps 7f6e2c100000-7f6e2c101000 r--s 00000000 00:24 15813027 /foo The bogus path is derived from the f_path of the intermediate backing file, whose mount is a private clone that d_path() cannot resolve. Fix this by using file_user_path(), which returns the outermost user-visible path for backing files and falls back to &user_file->f_path for regular files. This restores the behavior of commit 924577e4f6ca ("ovl: Fix nested backing file paths") for overlayfs and also fixes the same problem for the other backing_file_open() callers, fuse passthrough and erofs ishare, when their user file is itself a backing file. backing_tmpfile_open() has the same pattern but is not affected: it is only called by ovl_create_tmpfile() for the upper layer, and another overlayfs is rejected as upperdir by the DCACHE_OP_REAL check in ovl_mount_dir_check(), so its user_file can never be a backing file.
CVE-2026-89766 1 Linux 1 Linux Kernel 2026-09-11 2.5 Low
In the Linux kernel, the following vulnerability has been resolved: pidfd: hold exec_update_lock around namespace ioctl The PIDFD_GET_*_NAMESPACE ioctls in pidfd_ioctl() perform a filesystem credentials ptrace access check before handing out a namespace file descriptor. The accompanying comment states that the code "mirrors nsfs behavior", but, unlike the corresponding procfs paths, it does so without holding the target task's exec_update_lock. proc_ns_get_link() and proc_ns_readlink() both take exec_update_lock for reading around the ptrace check and the namespace lookup, so that the credentials used for the access decision match those of the task when its namespace is read. Without it, a caller can pass the check against the target's old credentials and then read the namespace after the target has execve()'d a setuid binary and committed new credentials -- accessing namespace information it should have been denied. Hold exec_update_lock for reading around the ptrace check and the namespace lookup so that pidfd truly mirrors nsfs behavior, as the comment already claims. open_namespace() itself runs outside the lock: once a namespace reference is obtained it carries its own refcount and is opened with the caller's own credentials, so a concurrent execve() on the target can no longer affect the outcome.
CVE-2026-89765 1 Linux 1 Linux Kernel 2026-09-11 5.3 Medium
In the Linux kernel, the following vulnerability has been resolved: timers/itimer: Zero-init old itimerval before copy to userspace On native sparc64, struct __kernel_old_timeval contains a four-byte hole after tv_usec because tv_sec is 64-bit while __kernel_suseconds_t is 32-bit. put_itimerval() fills only the named fields in a stack-allocated __kernel_old_itimerval and copies the entire object to userspace, so getitimer() can expose the two padding holes. Zero-initialize the aggregate before assigning the fields so implicit padding is deterministic before it crosses the user/kernel boundary.
CVE-2026-89763 1 Linux 1 Linux Kernel 2026-09-11 6.0 Medium
In the Linux kernel, the following vulnerability has been resolved: KEYS: trusted: Fix TPM teardown ordering trusted_tpm_exit() drops the TPM chip reference and frees the digest array before unregistering the trusted key type. key_type_lookup() holds key_types_sem for reading until the key operation finishes, while unregister_key_type() takes it for writing. It therefore provides the synchronization point that must precede backend teardown. The current order permits this interleaving: CPU 0 CPU 1 trusted_tpm_exit() key_type_lookup("trusted") put_device(&chip->dev) trusted_tpm_seal() kfree(digests) pcrlock() unregister_key_type() tpm_pcr_extend(..., digests) CPU 1 can consequently dereference the freed digest array. The chip can also be released before callbacks stop using it. KASAN reported: BUG: KASAN: slab-use-after-free in tpm_pcr_extend+0x1f0/0x200 Read of size 2 at addr ffff88810872d000 by task poc/89 Call Trace: tpm_pcr_extend+0x1f0/0x200 pcrlock+0x42/0x70 [trusted] trusted_tpm_seal+0x1b6/0x570 [trusted] trusted_instantiate+0x293/0x340 [trusted] __key_instantiate_and_link+0xb2/0x2b0 __key_create_or_update+0x61e/0xb50 __do_sys_add_key+0x1b8/0x310 Allocated by task 88: __kmalloc_noprof+0x1a7/0x490 do_one_initcall+0xa1/0x390 do_init_module+0x2df/0x840 Freed by task 90: kfree+0x131/0x3c0 trusted_tpm_exit+0x59/0xa0 [trusted] __do_sys_delete_module+0x346/0x510 Move unregister_key_type() before releasing either resource. This stops new lookups and waits for in-flight key operations to finish before the backend state is destroyed.
CVE-2026-89761 1 Linux 1 Linux Kernel 2026-09-11 6.5 Medium
In the Linux kernel, the following vulnerability has been resolved: apparmor: fix out-of-bounds write when null terminating a label vec aa_vec_unique() null terminates at vec[n - dups] when VEC_FLAG_TERMINATE is passed. If the components are all distinct no duplicates are dropped, dups is 0 and the terminator goes to vec[n], so the caller has to provide room for n + 1 entries. aa_label_strn_parse() sets up its vector with vec_setup(profile, vec, len, gfp) and then calls aa_vec_unique(vec, len, VEC_FLAG_TERMINATE), but vec_setup() does not reserve the terminator entry. Up to LOCAL_VEC_ENTRIES it uses the local array of LOCAL_VEC_ENTRIES pointers, above that it allocates exactly len pointers. The terminator therefore lands one entry past the end of the local array when len is LOCAL_VEC_ENTRIES, and one entry past the end of the allocation when len is larger. len comes from the number of "//&" separated components in the label name and label_count_strn_entries() does not bound it. An unprivileged task reaches the parse by writing to /proc/self/attr/apparmor/current or through lsm_set_self_attr(2), both of which go through do_setattr(), and the name is parsed before the change_profile permission is checked. The query_label() path behind the securityfs .access file, which is mode 0666, performs no permission check at all. Every component has to resolve to a loaded profile, so a system with policy loaded is required. The other two VEC_FLAG_TERMINATE users work on a label vec that aa_label_alloc() has already sized with "+ 1 for null terminator entry on vec". Reserve the same entry in vec_setup() and DEFINE_VEC(). Passing len + 1 from the caller instead would move len == LOCAL_VEC_ENTRIES out of the local array and into kzalloc().
CVE-2026-89760 1 Linux 1 Linux Kernel 2026-09-11 5.7 Medium
In the Linux kernel, the following vulnerability has been resolved: mm, swap: don't free a hibernation slot that is in the swap cache A slot with a folio in the swap cache is freed when the folio leaves the cache, not when its count drops. swap_put_entries_cluster() follows that rule. swap_free_hibernation_slot() does not, it calls __swap_cluster_free_entries() whether or not a folio sits on the slot. Cluster readahead can put one there. It walks a raw page_cluster sized window of offsets around the faulting entry, and a hibernation slot passes __swap_cache_add_check() because it is not a folio and its count is not zero. Freeing the slot then clears the entry under that folio. The folio is now unreachable from the swap table, and the offset goes back to the allocator. The folio is still on the LRU though, so reclaim can pick it up later. It then takes the old offset out of folio->swap and overwrites the table entry there, which by then may belong to someone else. This bug can trigger silent memory corruption, process crashes, or data instability across completely unrelated userspace applications - typically occurring when uswsusp is preparing the hibernation image. I found this while working on giving hibernation slots their own marker in the swap table, which I had discussed with Kairui. (https://lore.kernel.org/linux-mm/abp7aDgYLrxF3Me8@KASONG-MC4/) As far as I know there are no reports, so there is no Reported-by/Closes to add. Check for a cached folio before freeing. The slot is then left in the ordinary state where only the swap cache holds it, and it is freed when the folio leaves the cache, either through the reclaim below or through normal reclaim later.