Linux

Known Exploited Linux Vulnerabilities

The following Linux vulnerabilities have recently been marked by CISA as Known to be Exploited by threat actors.

Of the known exploited vulnerabilities above, 2 are in the top 1%, or the 99th percentile of the EPSS exploit probability rankings. 8 known exploited Linux vulnerabilities are in the top 5% (95th percentile or greater) of the EPSS exploit probability rankings.

Top 10 Riskiest Linux Vulnerabilities

Based on the current exploit probability, these Linux vulnerabilities are on CISA's Known Exploited vulnerabilities list (KEV) and are ranked by the current EPSS exploit probability.

By the Year

In 2026 there have been 5071 vulnerabilities in Linux with an average score of 8.2 out of ten. Last year, in 2025 Linux had 5791 security vulnerabilities published. If vulnerabilities keep coming in at the current rate, it appears that number of security vulnerabilities in Linux in 2026 could surpass last years number. However, the average CVE base score of the vulnerabilities in 2026 is greater by 1.08.

Recent Linux Security Vulnerabilities

CVE	Date	Vulnerability	Products
CVE-2026-80724	Aug 28, 2026	Linux Kernel: PTP VMClock ReadOnly Mapping Escalation (CVE202680724) In the Linux kernel, the following vulnerability has been resolved: ptp: vmclock: prevent read-only mappings from becoming writable vmclock_miscdev_mmap() rejects writable mappings of the shared vmclock ABI page with -EROFS, but leaves VM_MAYWRITE set. Userspace can map the page read-only and then upgrade it to writable with mprotect(), after which the guest can corrupt the host-written timekeeping data (sequence counter, UTC time, TSC offset) that the vmclock ABI defines as read-only. Clear VM_MAYWRITE on the read-only path so the mapping cannot be upgraded, as i915 does for its read-only objects and as fixed in drm/vc4 (CVE-2026-68445) and drm/panthor (CVE-2024-53071).	Linux Kernel
CVE-2026-80722	Aug 28, 2026	Linux Kernel mac80211 TWT Param Validation Flaw (CVE-2026-80722) In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: validate individual TWT params before driver setup ieee80211_process_rx_twt_action() only partially validates a received S1G TWT setup frame before queueing it. An individual agreement can therefore reach ieee80211_s1g_rx_twt_setup() with twt->length too short for the full struct ieee80211_twt_params. The individual path passes twt to drv_add_twt_setup(). Both the tracepoint and the driver callback consume the complete parameters block, not merely req_type. Do not pass a short individual agreement to the driver. Broadcast agreements remain unchanged because they are rejected locally after accessing only req_type. [edit commit message to not overclaim lack of validation nor understate driver impact]	Linux Kernel
CVE-2026-80723	Aug 28, 2026	Linux KERNEL OOB in fdt_scan_reserved_mem for excessive reservedmemory regions In the Linux kernel, the following vulnerability has been resolved: of: reserved_mem: prevent OOB when too many dynamic regions are defined On boot, fdt_scan_reserved_mem() saves each dynamically-placed /reserved-memory subnode into a local array of size MAX_RESERVED_REGIONS. If the device tree defines more than MAX_RESERVED_REGIONS dynamically-placed regions, fdt_scan_reserved_mem() writes past the end of the local array. Add a bounds check that logs an error and skips the excess regions, restoring the original behavior.	Linux Kernel
CVE-2026-80720	Aug 28, 2026	Linux kernel: iomap_split_ioend bio_set exhaustion causes deadlock In the Linux kernel, the following vulnerability has been resolved: iomap: add a separate bio_set for iomap_split_ioend iomap_split_ioend can split bios that already come from iomap_ioend_bioset and thus deadlock when the bioset is exhausted. Add a separate bio_set to avoid this deadlock. Christian Brauner <brauner@kernel.org> says: Mark iomap_ioend_split_bioset static as it is only used in ioend.c, fixing the sparse warning reported by the kernel test robot.	Linux Kernel
CVE-2026-80721	Aug 28, 2026	Linux Kernel Bluetooth ISO: Dangling hcon Ref in iso_conn Del In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: ensure no dangling hcon references in iso_conn After iso_conn_del(), ISO sockets should not dereference the hcon any more. Currently, clearing iso_conn::hcon relies on iso_conn_del() releasing the last reference to the iso_conn. Simplify this by explicitly clearing conn->hcon in iso_conn_del(), to avoid more complex reasoning on races about who holds the last reference.	Linux Kernel
CVE-2026-80719	Aug 28, 2026	Linux Kernel MGLRU stale batch updates cause premature OOMs (CVE-2026-80719) In the Linux kernel, the following vulnerability has been resolved: mm: mglru: fix stale batch updates after memcg reparenting The mglru page table walker batches per-generation size deltas in walk->nr_pages while walking page tables without holding the lruvec lock. The reset_batch_size() later folds those deltas into walk->lruvec under the lruvec lock. The page table walker can run concurrently with the memcg reparenting path as follows: CPU0 CPU1 ==== ==== walk_mm --> walk_page_range --> update_batch_size --> walk->nr_pages += delta mem_cgroup_css_offline --> memcg_reparent_objcgs --> lock lruvec lru_gen_reparent_memcg --> reparent child folios to parent unlock lruvec lock lruvec reset_batch_size --> child lrugen->nr_pages += delta This will trigger the following warning in lru_gen_exit_memcg(): VM_WARN_ON_ONCE(memchr_inv(lruvec->lrugen.nr_pages, 0, sizeof(lruvec->lrugen.nr_pages))); And the user-visible impact of underestimated nr_pages in MGLRU was premature OOMs because MGLRU does not try to reclaim memory when nr_pages reaches zero, but there are still more pages. To fix it, make reset_batch_size() check CSS_DYING under RCU before flushing the pending batch. A non-dying memcg keeps the original lruvec stable against RCU-delayed offlining; a dying memcg redirects the deltas to the first non-dying ancestor.	Linux Kernel
CVE-2026-80718	Aug 28, 2026	Linux Kernel: percpu-km bitmap overflow in pcpu_create_chunk() In the Linux kernel, the following vulnerability has been resolved: mm/percpu-km: fix bitmap overflow and accounting in pcpu_create_chunk() In pcpu_create_chunk(), nr_pages is the total contiguous backing allocation, i.e., nr_units * pcpu_unit_pages, but pcpu_chunk_populated() uses it to set chunk->populated, whose size is pcpu_unit_pages, bitmap. Since bit N in chunk->populated means page offset N inside every unit is backed. When nr_units > 1, the function writes beyond chunk->populated. Fix it by using chunk->nr_pages. It also fixes the global pcpu_nr_empty_pop_pages accounting, since pcpu_balance_free() only iterates up to chunk->nr_pages. Commit a63d4ac4ab609 ("percpu: make percpu-km set chunk->populated bitmap properly") introduced the bitmap overflow issue. Later, commit b539b87fed37f ("percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated") added pcpu_nr_empty_pop_pages and caused the accounting issue.	Linux Kernel
CVE-2026-80717	Aug 28, 2026	Linux Kernel sctp Adaptation Indication Param Length Bypass In the Linux kernel, the following vulnerability has been resolved: sctp: validate Adaptation Indication parameter length The Adaptation Layer Indication parameter contains a fixed 32-bit Adaptation Code Point after its parameter header. However, sctp_verify_param() accepts a header-only parameter because the generic parameter walker only requires the header to be present. sctp_process_param() then reads adaptation_ind beyond the declared parameter. When the malformed parameter is last in an INIT, the read starts at the receive skb tail, and the value is copied into the state cookie returned in the INIT ACK. This may disclose four receive-buffer tail bytes. Require the declared parameter length to match the fixed structure size and abort the association through the existing invalid parameter length path otherwise.	Linux Kernel
CVE-2026-80716	Aug 28, 2026	Linux Kernel ALSA PCM Drain Wait Vulnerability In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: wake linked drain waiters on unlink snd_pcm_drain() on a linked stream parks an on-stack wait entry on the drained peer's runtime->sleep, and after schedule_timeout() removes it only if that peer is still found in the caller's group. If group membership changes during the wait and the sleep ends by signal or timeout (so autoremove_wake_function() does not run), finish_wait() is skipped and snd_pcm_drain() returns with the entry still queued on that stream's sleep list; a later wake_up() then walks a freed stack frame. This is reachable by unlinking either the drained or the draining stream. Unlike the close path (snd_pcm_drop() -> snd_pcm_post_stop()), snd_pcm_unlink() never wakes the sleep queues. Wake every group member under the group lock before the membership change, so a linked drainer is released and drops its entry while the streams are still grouped. The window was opened when snd_pcm_link_rwsem stopped being held across the wait and the removal became conditional on group membership (see Fixes). The later switch to finish_wait() kept that conditional removal, so the signal/timeout case remained.	Linux Kernel
CVE-2026-80715	Aug 28, 2026	Linux kernel igc driver NAPI synchronization bug in XDP zero-copy In the Linux kernel, the following vulnerability has been resolved: igc: remove napi_synchronize() in igc_down() When an AF_XDP zero-copy application is killed abruptly, the XSK pool is torn down but NAPI keeps polling. igc_clean_rx_irq_zc() then returns the full budget on every poll, so napi_complete_done() never clears NAPI_STATE_SCHED. igc_down() calls napi_synchronize() before napi_disable(), so it spins forever waiting for that bit and the interface never goes down. Drop the napi_synchronize() and let napi_disable() do the job -- it sets NAPI_STATE_DISABLE, which forces the stuck poll to complete. Reorder it ahead of igc_set_queue_napi() so the NAPI mapping is cleared only after polling has stopped, matching the recent igb fix b1e067240379.	Linux Kernel
CVE-2026-80714	Aug 28, 2026	Linux Kernel IPVS: Prevent One-Packet Flag Propagation to Synced Connections In the Linux kernel, the following vulnerability has been resolved: ipvs: do not propagate one-packet flag to synced conns Synced connections can be created before their destination exists. When the destination is later added, ip_vs_bind_dest() copies connection flags from the destination into cp->flags. IP_VS_CONN_F_ONE_PACKET connections are not synced. If a synced connection inherits IP_VS_CONN_F_ONE_PACKET while it is already hashed, expiry can treat it as a one-packet connection and skip unlinking the existing conn_tab node, leaving stale hash nodes pointing at a freed struct ip_vs_conn. Drop IP_VS_CONN_F_ONE_PACKET from destination flags when binding synced connections.	Linux Kernel
CVE-2026-80713	Aug 28, 2026	Linux Kernel: Preserve io_uring Task Restrictions Across Exec In the Linux kernel, the following vulnerability has been resolved: io_uring: preserve task restrictions across exec Per-task restrictions apply to all rings created by a task. Once installed, they should not be dropped across exec. For a task that has used io_uring, the exec cancellation path calls __io_uring_free(). This frees both the task context and the per-task restriction, so a ring created after exec is unrestricted. Split task context cleanup into io_uring_free_tctx(), and use it from the exec cancellation path. Keep __io_uring_free() for final task cleanup, where both the context and restriction are released.	Linux Kernel
CVE-2026-80712	Aug 28, 2026	Linux Kernel SPI-NAND Off-by-One SET_FEATURE Write Vulnerability In the Linux kernel, the following vulnerability has been resolved: spi: spi-qpic-snand: write the feature value before executing SET_FEATURE qcom_spi_send_cmdaddr() programs NAND_FLASH_CMD/NAND_EXEC_CMD and submits the descriptors, which makes the controller execute the command immediately. For SPINAND_SET_FEATURE the value to be written is only placed into NAND_FLASH_FEATURES afterwards, by qcom_spi_io_op(), in a second submission - so the chip is programmed with whatever that register happened to hold from a previous operation, and the intended value is only applied by the *next* SET_FEATURE. Measured on a TP-Link Archer AX55 v1 (IPQ5018, ESMT F50L1G41LB): writing 0x40 to the configuration register (0xb0) leaves the chip at 0x00, and the subsequent write of 0x00 leaves it at 0x40 - every write lands one operation late. This stayed unnoticed until v6.18 added SPI-NAND OTP support together with OTP entries for ESMT chips. spinand_otp_rw() enables OTP mode, reads, and disables it again, and mtd_otp_nvmem_add() does this during MTD registration. With the off-by-one, the "disable" write actually applies the previously requested value, so CFG_OTP_ENABLE ends up set: the chip stays in OTP mode, every subsequent array read returns the OTP area instead of the array (UBI reports an empty device) and all writes fail with -EIO because the OTP area is write protected. On this board that makes the whole flash unusable and the device unbootable. Write the feature value into NAND_FLASH_FEATURES as part of the same transaction, before NAND_EXEC_CMD. While at it, copy only the bytes the operation actually carries - the previous code dereferenced a 4-byte pointer on a one-byte buffer (spinand->scratchbuf). With this patch the flash contents read back bit-identical to a known-good dump of the same board taken under the vendor firmware (md5-verified across partitions), and writes work.	Linux Kernel
CVE-2026-80711	Aug 28, 2026	Linux Kernel max17040 Driver Uninitialized Status Leak In the Linux kernel, the following vulnerability has been resolved: power: supply: max17040: handle missing status supplier MAX17040 does not report charger state itself, so the driver forwards POWER_SUPPLY_PROP_STATUS to a supplier power supply. If no supplier is registered, power_supply_get_property_from_supplier() returns -ENODEV and leaves the output value untouched. max17040_get_property() currently ignores that error and returns success, so userspace can read an uninitialized status value from the battery power supply. This happens on systems that use the fuel gauge without a charger supplier relationship in firmware. Return POWER_SUPPLY_STATUS_UNKNOWN when no supplier provides STATUS, and propagate other supplier lookup errors.	Linux Kernel
CVE-2026-80710	Aug 28, 2026	Linux Kernel s390 DASD: Buffer Overwrite in Device Format Check In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Fix undersized format-check buffer fmt_buffer_size in dasd_eckd_check_device_format() is declared as int, even though one of the multiplicands, sizeof(struct eckd_count), is a size_t. The expression trkcount * rpt_max * sizeof(struct eckd_count) is therefore correctly evaluated at 64-bit width, but the result is silently truncated when it is stored back into the 32-bit fmt_buffer_size variable. For a sufficiently large track range (start_unit/stop_unit are caller-controlled) this truncation yields a buffer size far smaller than the number of tracks actually requested. kzalloc() then succeeds with an undersized allocation, while the subsequent channel program build still operates on the untruncated track count and writes past the end of that buffer. Compute the buffer size with check_mul_overflow() and keep it in a size_t, so that a value that no longer fits results in -EINVAL instead of a silently truncated allocation size.	Linux Kernel
CVE-2026-80709	Aug 28, 2026	Linux Kernel s390/zcrypt EP11 CPRB Domain Limit Bypass In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix wrong domain value verification with EP11 CPRBs There is a wrong upper limit check for the domain value when an EP11 CPRB is processed for sending to a crypto card. This check is only active on custom device nodes but may lead to access heap memory behind perms->adm when an administrative CPRB is sent. Add correct limit (AP_DOMAINS = 256) checking to fix this.	Linux Kernel
CVE-2026-80708	Aug 28, 2026	Linux Kernel s390/zcrypt: Missing Mem Scrub on Clear Key Import (CVE202680708) In the Linux kernel, the following vulnerability has been resolved: s390/zcrypt: Fix missing mem scrub at clear key import in cca_clr2cipherkey() The helper function _ip_cprb_helper() uses internal buffer memory for building and processing CPRBs. After use this buffer was never scrubbed which could lead to leaving for example clear key material in memory which could be exposed via tricky reuse of this same memory. Extend the _ip_cprb_helper() function with another parameter 'scrub' used to steer scrubbing of this buffer. So now the caller has the opportunity to decide if scrubbing is needed or not. Extend the clear key to secure key token import process in function cca_clr2cipherkey() to tell the helper function from above to scrub the cprb buffer when the clear key value is part of the request data. Add explicit scrubbing on return from function cca_clr2cipherkey() for the random EXOR buffer and the cprb buffer. Overall this cleans the internal used buffer in case of clear key import to prevent sensitive data to get exposed.	Linux Kernel
CVE-2026-80707	Aug 28, 2026	Linux Kernel: Zero Residual Data in J1939 Session Buffer (CVE-2026-80707) In the Linux kernel, the following vulnerability has been resolved: can: j1939: transport: j1939_session_fresh_new(): initialize receive buffer Zero the allocated buffer in j1939_session_fresh_new() to ensure it contains no residual data. While there is a potential performance impact if users allocate maximum sized ETP buffers, most real-world use cases are not noticeably affected since the maximum known buffer size is typically around 65K. [mkl: add Message-ID]	Linux Kernel
CVE-2026-80706	Aug 28, 2026	Linux Kernel fw_parse OoB: Trunc Rec Causes Read Overflow In the Linux kernel, the following vulnerability has been resolved: can: softing: fw_parse(): validate firmware record spans fw_parse() reads a fixed record header, a firmware-provided payload, and a trailing checksum without knowing the end of the firmware blob. A truncated record can therefore make those reads exceed the blob. The same record also supplies addresses and lengths for writes into DPRAM. The generic loader uses wrap-prone mixed signed arithmetic for its bounds check, while the application loader does not bound the staging copy at all. Pass the firmware end to the parser and validate the full source record. Use a signed wide offset for generic DPRAM records and validate the application staging span against the mapped DPRAM before copying.	Linux Kernel
CVE-2026-80705	Aug 28, 2026	Linux Kernel: DRM_AMD Display Phantom Plane Segfault Prevention In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: check if dml21_add_phantom_plane() is successful Verify that the phantom plane was allocated to avoid a later segfault. (cherry picked from commit 5adb54abe5a8e82cbff7f8806db30a5f4924329f)	Linux Kernel
CVE-2026-80704	Aug 28, 2026	Linux Kernel: drm/amd Driver Null Logger Deref In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: use proper context for logging The same as the rest of the code, get_ss_info_from_atombios() uses calc_pll_cs->ctx->logger for logging. But calc_pll_cs->ctx is initialized only later in calc_pll_max_vco_construct(). Therefore, any output using DC_LOG_SYNC() leads to a NULL pointer deference in get_ss_info_from_atombios(). According to Sashiko, the very same problem exists in dce112_get_pix_clk_dividers() and dcn3_get_pix_clk_dividers() too. To avoid accessing the NULL context, use clk_src->base.ctx->logger everywhere. That context in base is initialized earlier in dce110_clk_src_construct() and dce112_clk_src_construct(). Before get_ss_info_from_atombios() or Sashiko's get_pix_clk_dividers functions above are actually called. This is done by redefining DC_LOGGER to CTX->logger. Before: dce110_clk_src_construct() did: -> sets clk_src->base.ctx = ctx; -> ss_info_from_atombios_create() -> get_ss_info_from_atombios() <- uses calc_pll_cs->ctx # BOOM -> calc_pll_max_vco_construct() <- sets calc_pll_cs->ctx After: dce110_clk_src_construct() does: -> sets clk_src->base.ctx = ctx; -> ss_info_from_atombios_create() -> get_ss_info_from_atombios() <- uses clk_src->base.ctx (cherry picked from commit 6f16fcbb0c46a87e3d9685407e906573d60104b0)	Linux Kernel
CVE-2026-80703	Aug 28, 2026	Linux Kernel KFD_IOC_DBG_TRAP_DISABLE Auth Bypass in amdkfd In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Fix missing authorization check in KFD_IOC_DBG_TRAP_DISABLE Prevent unauthorized termination of active GPU debug sessions. Previously, users with /dev/kfd access could terminate another process's debug session without proper ownership or ptrace authorization. (cherry picked from commit 4db4c5ffd5585b72622ecf6ffedf2da258ee23f5)	Linux Kernel
CVE-2026-80702	Aug 28, 2026	Linux Drm/Vmwgfx: Guest Mem Size Bitfield Reset Causes Dirty-Tracking Leak In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: fix guest_memory_dirty bitfield clobbered as size Two sites in vmwgfx_resource.c assign boolean literals to res->guest_memory_size, which is an unsigned long allocation-size field; the intended target is the adjacent res->guest_memory_dirty bitfield. After the assignments the field holds 0 or 1 instead of the resource's MOB allocation size: - vmw_resource_release() writes 0 (false), and - vmw_resource_unbind_list() writes 1 (true). Subsequent revalidation paths read guest_memory_size when computing the dirty page range (vmw_bo_dirty_transfer_to_res()) and the buffer allocation size (vmw_resource_buf_alloc()), producing zero-length walks or wrap-around ranges that read or write past the MOB bitmap. The dirty-tracking intent of the original code (mark the resource as dirtied since the last sync) is also lost, since guest_memory_dirty is never updated. Rename both assignments to guest_memory_dirty.	Linux Kernel
CVE-2026-80701	Aug 28, 2026	Linux Kernel drm/vmwgfx: block oversized cursor updates abusing MOB In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: enforce cursor size limits for MOB cursors vmw_cursor_plane_atomic_check() bounds cursor width and height only on the legacy update path; the SVGA_CAP2_CURSOR_MOB path -- the default on modern hosts -- accepts any size. When the requested size exceeds SVGA_REG_CURSOR_MAX_DIMENSION or SVGA_REG_MOB_MAX_SIZE, vmw_cursor_mob_get() returns -EINVAL and leaves vps->cursor.mob NULL. Its return value is then discarded in vmw_cursor_plane_prepare_fb(), so the subsequent vmw_cursor_update_mob() calls vmw_bo_map_and_cache(NULL) and oopses inside vmw_bo_map_and_cache_size() on the tbo.base.size load. Reachable from any DRM master via DRM_IOCTL_MODE_CURSOR2 with a sufficiently large width or height (e.g. cursor_max_dim + 1). Reject oversized cursors in atomic_check for both MOB-backed cursor update types. The MOB byte-size limit only applies to the SVGA_CAP2_CURSOR_MOB path (vmw_cursor_mob_size() returns 0 for GB_ONLY); compute the required MOB size in 64-bit to avoid overflow when very large dimensions are requested. In prepare_fb only call vmw_cursor_mob_get()/_map() for VMW_CURSOR_UPDATE_MOB -- the GB_ONLY path uses bo->map.virtual directly and would otherwise be silently downgraded to NONE on hosts without SVGA_CAP2_CURSOR_MOB (where vmw_cursor_mob_get() always returns -EINVAL). Degrade the update to NONE if vmw_cursor_mob_get() or vmw_cursor_mob_map() fails so the update path does not run with a NULL backing MOB.	Linux Kernel
CVE-2026-80700	Aug 28, 2026	Linux Kernel vmwgfx External BO Copy Bounds Overflow In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: validate external BO copy bounds for both stride paths vmw_external_bo_copy() trusts caller-supplied offsets, strides, and heights and operates on imported dma-buf vmaps: - The equal-stride memcpy() bound was clamped after subtracting the offsets from dst_size and src_size; an offset larger than the BO size wraps the unsigned subtraction to a huge value and the resulting memcpy() runs off the end of the vmap. dst_stride * height is also a u32 multiplication that can overflow. - The non-equal-stride row-by-row path had no bound at all. The loop touches bytes through offset + (height - 1) * stride + width_in_bytes, with only a WARN_ON(dst_stride < width_in_bytes), and could likewise step past the end of either mapping. The offsets and strides are derived from STDU/SOU plane state, so a configured CRTC submitting a crafted atomic commit on an imported framebuffer can reach this path. Validate the exact row-copy endpoint against each BO's size up front using check_mul_overflow() and check_add_overflow(). Use the bulk memcpy() path only when width_in_bytes covers the whole stride; otherwise copy one row at a time so partial-row updates near the bottom of a framebuffer remain valid. Also reject zero strides and stride < width_in_bytes, both of which the row-by-row path cannot represent safely.	Linux Kernel
CVE-2026-80699	Aug 28, 2026	Linux Kernel KVM ARM64 VGIC Double-Deactivate CVE-2026-80699 In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: vgic: Avoid double-deactivate of IRQs in the nested context In the nested state, the physical interrupt has already been deactivated through the HW bit in the LR. The extra deactivation would be harmless but can hit an errata case on AmpereOne, so avoid it here. On AmpereOne, deactivating a physical interrupt through ICC_DIR_EL1 or ICC_EOIR1_EL1 (depending on EOImode) which is not active, but is the highest priority pending interrupt causes the cpu to lose the interrupt pending state and also prevents the delivery of future interrupts.	Linux Kernel
CVE-2026-80698	Aug 28, 2026	Double Free in idxd DMA ENGINE release callbacks CVE-2026-80698 In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix double free of wq, engine, and group structs The release callbacks for wq, engine, and group devices (idxd_conf_wq_release, idxd_conf_engine_release, idxd_conf_group_release) each call kfree() on the enclosing struct. The setup error paths and cleanup functions also call kfree() explicitly after put_device(), producing a double free whenever put_device() drops the reference count to zero and fires the release. In the setup functions, device_initialize() is called before device_add(), so the reference count is exactly 1 at the error sites. put_device() unconditionally fires the release, which frees the struct; the subsequent explicit kfree() then operates on freed memory. For idxd_setup_wqs(), the wq release callback also owns opcap_bmap and wqcfg. The error unwind additionally freed those fields explicitly before calling put_device(), causing further double frees on both. Remove the redundant explicit kfree() calls from all setup error paths and cleanup functions for wq, engine, and group structs, delegating sole ownership of those allocations to the release callbacks.	Linux Kernel
CVE-2026-80697	Aug 28, 2026	Linux Kernel erofs: Null PTR Deref via page cache sharing In the Linux kernel, the following vulnerability has been resolved: erofs: ensure valid f_path for page cache sharing Previously, backing files for page cache sharing were set up with f_path left as NULL (only f_inode was valid). It worked, but a recent mincore fix relies on f_path.mnt and crashes (found by "erofs/028" on 7.2-rc4): BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy) Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 RIP: 0010:__do_sys_mincore+0xc0/0x2c0 ... Specify valid paths using valid disconnected dentries together with erofs_ishare_mnt instead of leaving f_path empty, so they are more like real backing files in a pseudo filesystem and standard backing_file_open() can be used directly.	Linux Kernel
CVE-2026-80696	Aug 28, 2026	Linux Kernel ltc4282 HWMON OOB read of min alarm voltage In the Linux kernel, the following vulnerability has been resolved: hwmon: (ltc4282) Fix reading the minimum alarm voltage Coverity reports an out-of-bounds access when reading the minimum alarm voltage for the VGPIO channel. Add the missing return statement to fix the problem.	Linux Kernel
CVE-2026-80695	Aug 28, 2026	Linux Kernel sht3x hwmon Unaligned Access -> Alignment Fault on ARM/SPARC In the Linux kernel, the following vulnerability has been resolved: hwmon: (sht3x) Fix unaligned accesses Sashiko reports: In sht3x_update_client(), the 16-bit temperature and humidity values are extracted from a stack-allocated byte array using be16_to_cpup(). The pointers passed to this function are calculated as buf and buf + 3. Since the difference between the two pointers is an odd number of bytes, at least one of them is guaranteed to be at an unaligned offset. This will trigger an alignment fault on strict-alignment architectures such as ARMv5 or SPARC, resulting in a kernel panic. Fix the problem by using get_unaligned_be16() instead of be16_to_cpup(), and put_unaligned_be16() instead of cpu_to_be16().	Linux Kernel
CVE-2026-80694	Aug 28, 2026	Linux Kernel: mtk_eth_soc Poll Controller Crash via Wrong IRQ In the Linux kernel, the following vulnerability has been resolved: net: ethernet: mtk_eth_soc: pass eth to mtk_handle_irq_rx in poll_controller mtk_handle_irq_rx expects a struct mtk_eth * (matching the request_irq cookie), but mtk_poll_controller incorrectly passed the net_device *. Calling ndo_poll_controller with CONFIG_NET_POLL_CONTROLLER enabled would then crash.	Linux Kernel
CVE-2026-80693	Aug 28, 2026	Linux Kernel idpf Driver OOB Write via VIRTCHNL2 Alloc Vectors Reply In the Linux kernel, the following vulnerability has been resolved: idpf: bound interrupt-vector register fill to the allocated array idpf_get_reg_intr_vecs() fills the caller-allocated reg_vals[] array from the VIRTCHNL2_OP_ALLOC_VECTORS reply in adapter->req_vec_chunks, bounding its inner loop only by the per-chunk num_vectors. The array is sized separately: idpf_intr_reg_init() allocates kzalloc_objs(struct idpf_vec_regs, total_vecs) from caps.num_allocated_vectors and only checks the returned count after the fill. The sum of per-chunk num_vectors is never reconciled against total_vecs, so a reply with a small num_allocated_vectors but chunks summing higher writes past the end of reg_vals[]. Impact: a control plane (a PF or hypervisor device model) that returns a VIRTCHNL2_OP_ALLOC_VECTORS reply whose per-chunk num_vectors sum exceeds num_allocated_vectors writes struct idpf_vec_regs entries past the end of the reg_vals kmalloc allocation (KASAN slab-out-of-bounds write). Bound the fill loop to the array capacity passed in by the callers, mirroring the sibling idpf_vport_get_q_reg(). The existing num_regs < num_vecs check then rejects an undersized reply without the out-of-bounds write happening first.	Linux Kernel
CVE-2026-80692	Aug 28, 2026	Linux Kernel Bluetooth UAF via hci_sync conn freed during ACL/LE sync In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: hold conn in hci_connect_acl/le_sync() callbacks There is theoretical UAF if the conn is freed while the hci_sync task is running. Hold refcount to avoid that.	Linux Kernel
CVE-2026-80691	Aug 28, 2026	Linux Kernel: NULL Pointer Deref in SCSI iblock PR Ops Check In the Linux kernel, the following vulnerability has been resolved: scsi: target: iblock: Fix wrong PR ops NULL check for PREEMPT/RELEASE In the iblock_execute_pr_out() function, PRO_PREEMPT, PRO_PREEMPT_AND_ABORT, and PRO_RELEASE all perform callback capability checks through ops->pr_clear. The error check allows unimplemented hooks to pass through the gate, resulting dereferencing a NULL function pointer. Check whether the hooks that need to be called are supported.	Linux Kernel
CVE-2026-80690	Aug 28, 2026	Linux Kernel: Prevent Null-Ptr Deref in UFS Host RPmb List Init In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Initialize hba->rpmbs list in ufshcd Initialize the hba->rpmbs list in ufshcd_alloc_host() to prevent NULL pointer dereference in the device teardown path if ufs_rpmb_probe() fails.	Linux Kernel
CVE-2026-80689	Aug 28, 2026	Linux Kernel NULL Deref in mmio_trace_array Logging Functions In the Linux kernel, the following vulnerability has been resolved: tracing/mmiotrace: Add NULL check for mmio_trace_array in logging functions mmio_trace_rw() and mmio_trace_mapping() retrieve mmio_trace_array into tr and pass it to __trace_mmiotrace_rw() and __trace_mmiotrace_map(). If these functions are invoked while mmio_trace_array is NULL (e.g. before initialization or after disabled), accessing tr->array_buffer.buffer will result in a NULL pointer dereference crash. Fix this by adding an explicit NULL check for tr at the beginning of __trace_mmiotrace_rw() and __trace_mmiotrace_map().	Linux Kernel
CVE-2026-80688	Aug 28, 2026	Linux RISC-V vec_check_unaligned_access_speed All CPUs Init Bug In the Linux kernel, the following vulnerability has been resolved: riscv: drop __init from vec_check_unaligned_access_speed_all_cpus This function runs within a kthread and need not necessarily finish before system finishes boot and free_initmem() unmaps the .init.text section. This function makes calls to SBI for probing unaligned access speed, and if this is slow for some reason (say some debug prints were added to SBI), the kthread can still be running at this point and result in an instruction page fault when trying to fetch from the freed region. [ 25.642087] Unable to handle kernel paging request at virtual address ffffffff80a04ef8 [ 25.646694] Current vec_check_unali pgtable: 4K pagesize, 48-bit VAs, pgdp=0x00004000316e9000 [ 25.653170] [ffffffff80a04ef8] pgd=000010004be7e401, p4d=000010004be7e401, pud=000010004be7e001, pmd=000010000c3000e3 [ 25.661244] Oops [#1] [ 25.662997] Modules linked in: [ 25.665357] CPU: 3 UID: 0 PID: 42 Comm: vec_check_unali Not tainted 7.0.0-tt-blackhole-asrinivasan-00007-g30ff73f18211 #570 PREEMPTLAZY [ 25.674669] Hardware name: Tenstorrent Blackhole (DT) [ 25.678545] epc : vec_check_unaligned_access_speed_all_cpus+0x18/0x2c [ 25.683458] ra : vec_check_unaligned_access_speed_all_cpus+0x18/0x2c [ 25.688372] epc : ffffffff80a04ef8 ra : ffffffff80a04ef8 sp : ffff8f8000203e20 [ 25.693874] gp : ffffffff814dc168 tp : ffffaf8001ad9900 t0 : 0000000000000000 [ 25.699401] t1 : fffffffffffffff0 t2 : ffffaf8001ad9a10 s0 : ffff8f8000203e30 [ 25.704912] s1 : ffffaf80018dc780 a0 : 0000000000000000 a1 : 0000000000000002 [ 25.710407] a2 : 00000000000001f0 a3 : 0000000000000018 a4 : 0000000000000000 [ 25.715917] a5 : 0000000000000000 a6 : ffffaf8001c03d98 a7 : ffffaf8001c03e30 [ 25.721419] s2 : ffff8f8000023c98 s3 : ffffaf8001aa1240 s4 : ffffffff80a04ee0 [ 25.726937] s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000 [ 25.732450] s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000 [ 25.737944] s11: 0000000000000000 t3 : 0000000000000002 t4 : 0000000000000402 [ 25.743481] t5 : 0000000000000040 t6 : 0000000000000004 ssp : 0000000000000000 [ 25.749024] status: 0000000200000120 badaddr: ffffffff80a04ef8 cause: 000000000000000c [ 25.755060] [<ffffffff80a04ef8>] vec_check_unaligned_access_speed_all_cpus+0x18/0x2c [ 25.760964] [<ffffffff80047a10>] kthread+0xd8/0xfc [ 25.764660] [<ffffffff80010c48>] ret_from_fork_kernel+0x18/0x1c4 [ 25.769220] [<ffffffff80895fe6>] ret_from_fork_kernel_asm+0x16/0x18 [ 25.774018] Code: cccc cccc cccc cccc cccc cccc cccc cccc cccc cccc (cccc) cccc Drop __init from its signature so that this doesn't happen.	Linux Kernel
CVE-2026-80687	Aug 28, 2026	Linux Kernel iommufd/viommu igroup lock deadlock In the Linux kernel, the following vulnerability has been resolved: iommufd/viommu: Release the igroup lock on the vdevice_size error path iommufd_vdevice_alloc_ioctl() takes idev->igroup->lock, then validates the driver's vdevice_size against the core structure size with a WARN_ON_ONCE. On failure that guard jumps to out_put_idev, below out_unlock_igroup, so it skips the mutex_unlock(), leaving the igroup lock held and deadlocking the next vDEVICE operation on that group. Jump to out_unlock_igroup instead.	Linux Kernel
CVE-2026-80686	Aug 28, 2026	Linux Kernel: Guard pte_pfn/pte_dirty on Non-Present PTE In the Linux kernel, the following vulnerability has been resolved: mm: migrate_device: fix pte_pfn/pte_dirty called on non-present PTE pte_pfn() and pte_dirty() have undefined behaviour when called on a non-present PTE. In migrate_vma_collect_pmd(), these functions may be invoked on non-present entries (e.g., device-private entries), leading to potential crashes from pte_pfn() or incorrect dirty folio accounting from pte_dirty(). Fix both by guarding with pte_present() checks.	Linux Kernel
CVE-2026-80685	Aug 28, 2026	Linux kernel folio snapshot_page() read of non-existent __page_2 In the Linux kernel, the following vulnerability has been resolved: mm/util: don't read __page_2 for order-1 folios in snapshot_page() snapshot_page() currently reads __page_2 after checking nr_pages > 1, but it should only do so when nr_pages > 2. If an order-1 folio is allocated at the end of a vmemmap section, __page_2 will not exist and reading it will cause a fault. During DLPAR memory remove on a 22 TB ppc64le LPAR, snapshot_page() oopsed on the page isolation path while reading an order-1 folio's __page_2 from an adjacent absent section (unmapped vmemmap). Fix this to avoid reading memmap that doesn't exist (e.g., a vmemmap hole).	Linux Kernel
CVE-2026-80684	Aug 28, 2026	Linux Kernel KVM s390 PCI NULL Deref on AIBV Allocation Failure In the Linux kernel, the following vulnerability has been resolved: KVM: s390: pci: Fix NULL dereference on AIBV allocation failure The airq_iv_create() can return NULL on failure, but the return value was never checked. If it fails, zdev->aibv will be NULL and fail when dereferenced in kvm_zpci_set_airq(). Add a NULL check and free the previously allocated AISB bit and zdev->aisb on failure.	Linux Kernel
CVE-2026-80683	Aug 28, 2026	Linux Kernel Bluetooth SCO Reference Count Leak In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: give the socket its own sco_conn reference sco_conn_del() drops a reference it does not own. It takes one transient reference via sco_conn_hold_unless_zero() and releases it with the sco_conn_put() that follows sco_sock_hold(); the additional put in the !sk branch releases a second one: conn = sco_conn_hold_unless_zero(conn); ... sk = sco_sock_hold(conn); sco_conn_unlock(conn); sco_conn_put(conn); if (!sk) { sco_conn_put(conn); return; } When close() races the controller's Disconnection Complete, sco_chan_del() clears conn->sk and drops the socket's reference while sco_conn_del() is running. sco_conn_del() then sees sk == NULL, its own put drops the count to zero and frees the conn, and the second put writes to the freed kref: BUG: KASAN: slab-use-after-free in sco_conn_put.part.0+0x1a/0x190 Write of size 4 at addr ffff8881099dec74 by task kworker/u17:3/413 Workqueue: hci1 hci_rx_work Call Trace: sco_conn_put.part.0+0x1a/0x190 hci_disconn_complete_evt+0x1ee/0x3e0 hci_event_packet+0x54a/0x650 hci_rx_work+0x321/0x3d0 Allocated by task 413: sco_conn_add+0x72/0x1a0 sco_connect_cfm+0x88/0x670 Freed by task 413: sco_conn_del.isra.0+0x3f/0xf0 hci_disconn_complete_evt+0x1ee/0x3e0 refcount_t: underflow; use-after-free. The root cause is that the socket stores the connection without holding a reference of its own. __sco_chan_add() does: sco_pi(sk)->conn = conn; so the socket borrows whatever reference its caller happened to hold, and the callers paper over that with ad-hoc holds and puts. Give the socket a counted reference instead: __sco_chan_add() takes one and it is released together with the channel (sco_chan_del()) and in sco_sock_destruct(). With the socket holding its own reference, sco_conn_del() no longer needs the extra put and the redundant hold in sco_conn_ready() goes away. Making the socket own its reference means the connection is now actually freed on the error paths of sco_connect() where it used to leak, which in turn runs sco_conn_free() and its hci_conn_drop(conn->hcon). To keep the hci_conn accounting balanced, make that ownership explicit as well: sco_conn_add() consumes one hci_conn reference and the sco_conn owns it for its lifetime. sco_connect() hands over the reference returned by hci_connect_sco() and no longer drops it on the error paths; sco_connect_cfm(), which is not given a reference, takes one with hci_conn_hold() before handing it to sco_conn_add() (and drops it again if the allocation fails); and the explicit hci_conn_hold() in sco_conn_ready() is removed. Every reference then has a single, clear owner.	Linux Kernel
CVE-2026-80682	Aug 28, 2026	Linux RISCV Kernel: Physical Alignment Bug in vmemmap_start_pfn In the Linux kernel, the following vulnerability has been resolved: riscv/mm: use physical alignment for vmemmap_start_pfn RISC-V computes vmemmap_start_pfn by rounding phys_ram_base down to VMEMMAP_ADDR_ALIGN. That alignment must therefore be expressed in the physical-address domain. Commit 476849b0fba4 ("riscv/mm: align vmemmap to maximal folio size") attempted to account for the maximal folio alignment by feeding MAX_FOLIO_VMEMMAP_ALIGN directly into VMEMMAP_ADDR_ALIGN. However, MAX_FOLIO_VMEMMAP_ALIGN is measured in bytes of struct page storage, whereas VMEMMAP_ADDR_ALIGN is used to align a physical address. The mask-based compound_info encoding requires pfn_to_page(0) to be naturally aligned to MAX_FOLIO_VMEMMAP_ALIGN. Commit 9f94db4c7eaa ("mm/sparse: check memmap alignment for compound_info_has_mask()") added a check for that requirement and exposed the unit mismatch on systems such as QEMU virt, where the DRAM base is not aligned to MAX_FOLIO_NR_PAGES * PAGE_SIZE. Here is the log: [ 0.000000][ C0] ------------[ cut here ]------------ [ 0.000000][ C0] WARNING: mm/sparse.c:365 at sparse_init+0x58a/0x6fe, CPU#0: swapper/0 [ 0.000000][ C0] Modules linked in: [ 0.000000][ C0] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 7.2.0-rc3-g1d8304bdd65f #2 PREEMPT [ 0.000000][ C0] Hardware name: riscv-virtio,qemu (DT) [ 0.000000][ C0] epc : sparse_init+0x58a/0x6fe [ 0.000000][ C0] ra : sparse_init+0x58a/0x6fe [ 0.000000][ C0] epc : ffffffff86851c88 ra : ffffffff86851c88 sp : ffffffff88807a30 [ 0.000000][ C0] gp : ffffffff8a3bf240 tp : ffffffff88842080 t0 : ff600000ffab6000 [ 0.000000][ C0] t1 : 000000017fab6000 t2 : 65203a6573726363 s0 : ffffffff88807bc0 [ 0.000000][ C0] s1 : 000000000e000000 a0 : 0000000000000007 a1 : 0000000000000000 [ 0.000000][ C0] a2 : 0000000000000002 a3 : ffffffff86851c88 a4 : 0000000000000000 [ 0.000000][ C0] a5 : ffffffff88843080 a6 : 0000000000000003 a7 : 0000000000000000 [ 0.000000][ C0] s2 : ff60000000000000 s3 : 0040000000000000 s4 : 0004000000000000 [ 0.000000][ C0] s5 : ffffffff8a4d92e0 s6 : ff600000ffab55e0 s7 : ffffffff88384d00 [ 0.000000][ C0] s8 : 0000000000000003 s9 : ffffffff88384cc1 s10: ffffffff88384cc0 [ 0.000000][ C0] s11: ffffffff8a4daae0 t3 : ffffffff915e8b20 t4 : ffffffff915e8b20 [ 0.000000][ C0] t5 : ffffffff915e8b20 t6 : ffffffff915e8bc8 ssp : 0000000000000000 [ 0.000000][ C0] status: 0000000200000100 badaddr: ffffffff86851c88 cause: 0000000000000003 [ 0.000000][ C0] [<ffffffff86851c88>] sparse_init+0x58a/0x6fe [ 0.000000][ C0] [<ffffffff8683d396>] mm_core_init_early+0x116/0x1e30 [ 0.000000][ C0] [<ffffffff86801edc>] start_kernel+0xd2/0x848 Convert MAX_FOLIO_VMEMMAP_ALIGN to the equivalent physical alignment before using it in VMEMMAP_ADDR_ALIGN. This keeps the existing round_down() logic while making the resulting vmemmap base satisfy the mask-alignment requirement.	Linux Kernel
CVE-2026-80681	Aug 28, 2026	Linux kernel vxlan UAF via stale eth header after route_shortcircuit In the Linux kernel, the following vulnerability has been resolved: vxlan: re-fetch eth header after route_shortcircuit() Before route_shortcircuit(), the eth header pointer is cached from eth_hdr(skb). Inside route_shortcircuit(), pskb_may_pull() can be called, which may reallocate skb->head. In this case, returning to vxlan_xmit() leaves the cached eth pointer pointing to freed memory, leading to a use-after-free when dereferencing eth->h_dest. Fix this by updating eth = eth_hdr(skb) after calling route_shortcircuit().	Linux Kernel
CVE-2026-80680	Aug 28, 2026	Linux Kernel i2c: amd-mp2 Unregister Callback on Adapter Add Failure In the Linux kernel, the following vulnerability has been resolved: i2c: amd-mp2: Unregister callback on adapter add failure amd_mp2_register_cb() stores the platform I2C context in the MP2 PCI driver's callback table before the adapter is registered. If i2c_add_adapter() fails, probe returns and devres frees the context, but the PCI driver can still dereference the stale pointer from its IRQ and system-sleep callbacks. Unregister the callback before returning the adapter registration error.	Linux Kernel
CVE-2026-80679	Aug 28, 2026	Linux Kernel s390 DASD NULL Pointer Deref CVE-2026-80679 In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Fix potential NULL pointer dereference dasd_release_space() checks the implementation of the is_ese() discipline function before calling it to determine if a given device is an ESE DASD. The current usage of the logical AND operator will lead to a NULL pointer dereference as the function is called even if the function pointer is NULL. Fix this by using the logical OR operator.	Linux Kernel
CVE-2026-80678	Aug 28, 2026	Linux kernel: i2c_imx slave registration race & ISR NULL deref fix In the Linux kernel, the following vulnerability has been resolved: i2c: imx: Fix slave registration race and error handling In i2c_imx_reg_slave(), the slave pointer was assigned before pm_runtime_resume_and_get(). If pm_runtime_resume_and_get() failed, the error path returned without clearing i2c_imx->slave, leaving it non-NULL and causing all subsequent registration attempts to fail with -EBUSY. Additionally, because this driver uses a shared IRQ, the interrupt handler i2c_imx_isr() can execute concurrently and, after acquiring slave_lock, dereference i2c_imx->slave. The previous fix attempt added a lockless i2c_imx->slave = NULL on the error path, but that could race with the ISR under the lock and still cause a NULL pointer dereference. Fix both issues by deferring the assignment of i2c_imx->slave and i2c_imx->last_slave_event to after a successful resume, and by performing the assignment inside the slave_lock critical section. This guarantees that the slave pointer is never left stale on the error path and is always valid when observed by the interrupt handler.	Linux Kernel
CVE-2026-80677	Aug 28, 2026	Linux Kernel Dev_Has_Sync_State Read Race via dev->driver In the Linux kernel, the following vulnerability has been resolved: driver core: use READ_ONCE() for dev->driver in dev_has_sync_state() dev_has_sync_state() reads dev->driver twice without holding device_lock() -- once for the NULL check and once to dereference ->sync_state. Some callers only hold device_links_write_lock, which doesn't prevent a concurrent unbind from clearing dev->driver via device_unbind_cleanup(). Fix it by reading dev->driver exactly once with READ_ONCE(), pairing with the WRITE_ONCE() in device_set_driver().	Linux Kernel
CVE-2026-80676	Aug 28, 2026	Linux Kernel UAF via driver_override in hv vmbus driver In the Linux kernel, the following vulnerability has been resolved: Drivers: hv: vmbus: use generic driver_override infrastructure When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1]	Linux Kernel
CVE-2026-80675	Aug 28, 2026	Linux Kernel: libbpf Signed Loader Bypass Non-Exclusive Maps In the Linux kernel, the following vulnerability has been resolved: libbpf: Reject non-exclusive metadata maps in the signed loader The loader verifies map->sha against the metadata hash in its instructions. map->sha is calculated when BPF_OBJ_GET_INFO_BY_FD is called on the frozen map. While the map is frozen, the /signed loader/ must also ensure the map is exclusive, as, without exclusivity (which a hostile host could just omit when loading the loader), another BPF program with map access can mutate the contents afterwards, so the check passes on stale data. With the extra check as part of the signed loader, it now refuses to move on with map->sha validation if the host set it up wrongly.	Linux Kernel