In the Linux kernel, the following vulnerability has been resolved: btrfs: do proper folio cleanup when cow_file_range() failed [BUG] When testing with COW fixup marked as BUG_ON() (this is involved with the new pin_user_pages*() change, which should not result new out-of-band dirty pages), I hit a crash triggered by the BUG_ON() from hitting COW fixup path. This BUG_ON() happens just after a failed btrfs_run_delalloc_range(): BTRFS error (device dm-2): failed to run delalloc range, root 348 ino 405 folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28 ------------[ cut here ]------------ kernel BUG at fs/btrfs/extent_io.c:1444! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 0 UID: 0 PID: 434621 Comm: kworker/u24:8 Tainted: G OE 6.12.0-rc7-custom+ #86 Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] pc : extent_writepage_io+0x2d4/0x308 [btrfs] lr : extent_writepage_io+0x2d4/0x308 [btrfs] Call trace: extent_writepage_io+0x2d4/0x308 [btrfs] extent_writepage+0x218/0x330 [btrfs] extent_write_cache_pages+0x1d4/0x4b0 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190 filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x180/0x3b0 [btrfs] btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8 [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408 worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: aa1403e1 9402f3ef aa1403e0 9402f36f (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] That failure is mostly from cow_file_range(), where we can hit -ENOSPC. Although the -ENOSPC is already a bug related to our space reservation code, let's just focus on the error handling. For example, we have the following dirty range [0, 64K) of an inode, with 4K sector size and 4K page size: 0 16K 32K 48K 64K |///////////////////////////////////////| |#######################################| Where |///| means page are still dirty, and |###| means the extent io tree has EXTENT_DELALLOC flag. - Enter extent_writepage() for page 0 - Enter btrfs_run_delalloc_range() for range [0, 64K) - Enter cow_file_range() for range [0, 64K) - Function btrfs_reserve_extent() only reserved one 16K extent So we created extent map and ordered extent for range [0, 16K) 0 16K 32K 48K 64K |////////|//////////////////////////////| |<- OE ->|##############################| And range [0, 16K) has its delalloc flag cleared. But since we haven't yet submit any bio, involved 4 pages are still dirty. - Function btrfs_reserve_extent() returns with -ENOSPC Now we have to run error cleanup, which will clear all EXTENT_DELALLOC* flags and clear the dirty flags for the remaining ranges: 0 16K 32K 48K 64K |////////| | | | | Note that range [0, 16K) still has its pages dirty. - Some time later, writeback is triggered again for the range [0, 16K) since the page range still has dirty flags. - btrfs_run_delalloc_range() will do nothing because there is no EXTENT_DELALLOC flag. - extent_writepage_io() finds page 0 has no ordered flag Which falls into the COW fixup path, triggering the BUG_ON(). Unfortunately this error handling bug dates back to the introduction of btrfs. Thankfully with the abuse of COW fixup, at least it won't crash the kernel. [FIX] Instead of immediately unlocking the extent and folios, we keep the extent and folios locked until either erroring out or the whole delalloc range finished. When the whole delalloc range finished without error, we just unlock the whole range with PAGE_SET_ORDERED (and PAGE_UNLOCK for !keep_locked cases) ---truncated---

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2025-994 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: do proper folio cleanup when cow_file_range() failed (CVE-2024-57976)

    In the Linux kernel, the following vulnerability has been resolved:

    kernel: be more careful about dup_mmap() failures and uprobe registering (CVE-2025-21709)

    In the Linux kernel, the following vulnerability has been resolved:

    block: fix queue freeze vs limits lock order in sysfs store methods (CVE-2025-21807)

    In the Linux kernel, the following vulnerability has been resolved:

    block: mark GFP_NOIO around sysfs ->store() (CVE-2025-21817)

    In the Linux kernel, the following vulnerability has been resolved:

    iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE (CVE-2025-21833)

    In the Linux kernel, the following vulnerability has been resolved:

    net: better track kernel sockets lifetime (CVE-2025-21884)

    In the Linux kernel, the following vulnerability has been resolved:

    bnxt_en: Mask the bd_cnt field in the TX BD properly (CVE-2025-22108)

    In the Linux kernel, the following vulnerability has been resolved:

    ext4: goto right label 'out_mmap_sem' in ext4_setattr() (CVE-2025-22120)

    In the Linux kernel, the following vulnerability has been resolved:

    net_sched: hfsc: Fix a UAF vulnerability in class handling (CVE-2025-37797)

    In the Linux kernel, the following vulnerability has been resolved:

    vmxnet3: Fix malformed packet sizing in vmxnet3_process_xdp (CVE-2025-37799)

    In the Linux kernel, the following vulnerability has been resolved:

    driver core: fix potential NULL pointer dereference in dev_uevent() (CVE-2025-37800)

    In the Linux kernel, the following vulnerability has been resolved:

    fs/ntfs3: Keep write operations atomic (CVE-2025-37806)

    In the Linux kernel, the following vulnerability has been resolved:

    bpf: Fix kmemleak warning for percpu hashmap (CVE-2025-37807)

    In the Linux kernel, the following vulnerability has been resolved:

    crypto: null - Use spin lock instead of mutex (CVE-2025-37808)

    In the Linux kernel, the following vulnerability has been resolved:

    usb: typec: class: Fix NULL pointer access (CVE-2025-37809)

    In the Linux kernel, the following vulnerability has been resolved:

    usb: xhci: Fix invalid pointer dereference in Etron workaround (CVE-2025-37813)

    In the Linux kernel, the following vulnerability has been resolved:

    tty: Require CAP_SYS_ADMIN for all usages of TIOCL_SELMOUSEREPORT (CVE-2025-37814)

    In the Linux kernel, the following vulnerability has been resolved:

    irqchip/gic-v2m: Prevent use after free of gicv2m_get_fwnode() (CVE-2025-37819)

    In the Linux kernel, the following vulnerability has been resolved:

    xen-netfront: handle NULL returned by xdp_convert_buff_to_frame() (CVE-2025-37820)

    In the Linux kernel, the following vulnerability has been resolved:

    sched/eevdf: Fix se->slice being set to U64_MAX and resulting crash (CVE-2025-37821)

    In the Linux kernel, the following vulnerability has been resolved:

    net_sched: hfsc: Fix a potential UAF in hfsc_dequeue() too (CVE-2025-37823)

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: zoned: return EIO on RAID1 block group write pointer mismatch (CVE-2025-37827)

    In the Linux kernel, the following vulnerability has been resolved:

    mm/vmscan: don't try to reclaim hwpoison folio (CVE-2025-37834)

    In the Linux kernel, the following vulnerability has been resolved:

    netfs: Only create /proc/fs/netfs with CONFIG_PROC_FS (CVE-2025-37876)

    In the Linux kernel, the following vulnerability has been resolved:

    iommu: Clear iommu-dma ops on cleanup (CVE-2025-37877)

    In the Linux kernel, the following vulnerability has been resolved:

    perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init (CVE-2025-37878)

    In the Linux kernel, the following vulnerability has been resolved:

    usb: xhci: Fix isochronous Ring Underrun/Overrun event handling (CVE-2025-37882)

    In the Linux kernel, the following vulnerability has been resolved:

    bpf: Fix deadlock between rcu_tasks_trace and event_mutex. (CVE-2025-37884)

    In the Linux kernel, the following vulnerability has been resolved:

    KVM: x86: Reset IRTE to host control if *new* route isn't postable (CVE-2025-37885)

    In the Linux kernel, the following vulnerability has been resolved:

    net/mlx5: Fix null-ptr-deref in mlx5_create_{inner_,}ttc_table() (CVE-2025-37888)

    In the Linux kernel, the following vulnerability has been resolved:

    net_sched: hfsc: Fix a UAF vulnerability in class with netem as child qdisc (CVE-2025-37890)

    In the Linux kernel, the following vulnerability has been resolved:

    net: use sock_gen_put() when sk_state is TCP_TIME_WAIT (CVE-2025-37894)

    In the Linux kernel, the following vulnerability has been resolved:

    iommu: Fix two issues in iommu_copy_struct_from_user() (CVE-2025-37900)

    In the Linux kernel, the following vulnerability has been resolved:

    mm, slab: clean up slab->obj_exts always (CVE-2025-37908)

    In the Linux kernel, the following vulnerability has been resolved:

    net_sched: qfq: Fix double list add in class with netem as child qdisc (CVE-2025-37913)

    In the Linux kernel, the following vulnerability has been resolved:

    net_sched: ets: Fix double list add in class with netem as child qdisc (CVE-2025-37914)

    In the Linux kernel, the following vulnerability has been resolved:

    net_sched: drr: Fix double list add in class with netem as child qdisc (CVE-2025-37915)

    In the Linux kernel, the following vulnerability has been resolved:

    xsk: Fix race condition in AF_XDP generic RX path (CVE-2025-37920)

    In the Linux kernel, the following vulnerability has been resolved:

    vxlan: vnifilter: Fix unlocked deletion of default FDB entry (CVE-2025-37921)

    In the Linux kernel, the following vulnerability has been resolved:

    tracing: Fix oob write in trace_seq_to_buffer() (CVE-2025-37923)

    In the Linux kernel, the following vulnerability has been resolved:

    iommu/amd: Fix potential buffer overflow in parse_ivrs_acpihid (CVE-2025-37927)

    In the Linux kernel, the following vulnerability has been resolved:

    dm-bufio: don't schedule in atomic context (CVE-2025-37928)

    In the Linux kernel, the following vulnerability has been resolved:

    arm64: errata: Add missing sentinels to Spectre-BHB MIDR arrays (CVE-2025-37929)

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: adjust subpage bit start based on sectorsize (CVE-2025-37931)

    In the Linux kernel, the following vulnerability has been resolved:

    sch_htb: make htb_qlen_notify() idempotent (CVE-2025-37932)

    In the Linux kernel, the following vulnerability has been resolved:

    perf/x86/intel: KVM: Mask PEBS_ENABLE loaded for guest with vCPU's value. (CVE-2025-37936)

    In the Linux kernel, the following vulnerability has been resolved:

    tracing: Verify event formats that have %*p.. (CVE-2025-37938)

    In the Linux kernel, the following vulnerability has been resolved:

    arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs (CVE-2025-37948)

    In the Linux kernel, the following vulnerability has been resolved:

    xenbus: Use kref to track req lifetime (CVE-2025-37949)

    In the Linux kernel, the following vulnerability has been resolved:

    smb: client: Avoid race in open_cached_dir with lease breaks (CVE-2025-37954)

    In the Linux kernel, the following vulnerability has been resolved:

    virtio-net: free xsk_buffs on error in virtnet_xsk_pool_enable() (CVE-2025-37955)

    In the Linux kernel, the following vulnerability has been resolved:

    KVM: SVM: Forcibly leave SMM mode on SHUTDOWN interception (CVE-2025-37957)

    In the Linux kernel, the following vulnerability has been resolved:

    mm/huge_memory: fix dereferencing invalid pmd migration entry (CVE-2025-37958)

    In the Linux kernel, the following vulnerability has been resolved:

    bpf: Scrub packet on bpf_redirect_peer (CVE-2025-37959)

    In the Linux kernel, the following vulnerability has been resolved:

    memblock: Accept allocated memory before use in memblock_double_array() (CVE-2025-37960)

    In the Linux kernel, the following vulnerability has been resolved:

    ipvs: fix uninit-value for saddr in do_output_route4 (CVE-2025-37961)

    In the Linux kernel, the following vulnerability has been resolved:

    arm64: bpf: Only mitigate cBPF programs loaded by unprivileged users (CVE-2025-37963)

    In the Linux kernel, the following vulnerability has been resolved:

    x86/mm: Eliminate window where TLB flushes may be inadvertently skipped (CVE-2025-37964)

    In the Linux kernel, the following vulnerability has been resolved:

    usb: typec: class: Invalidate USB device pointers on partner unregistration (CVE-2025-37986)

    In the Linux kernel, the following vulnerability has been resolved:

    fix a couple of races in MNT_TREE_BENEATH handling by do_move_mount() (CVE-2025-37988)

    In the Linux kernel, the following vulnerability has been resolved:

    net: phy: leds: fix memory leak (CVE-2025-37989)

    In the Linux kernel, the following vulnerability has been resolved:

    module: ensure that kobject_put() is safe for module type kobjects (CVE-2025-37995)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: ipset: fix region locking in hash types (CVE-2025-37997)

    In the Linux kernel, the following vulnerability has been resolved:

    openvswitch: Fix unsafe attribute parsing in output_userspace() (CVE-2025-37998)

    In the Linux kernel, the following vulnerability has been resolved:

    fs/erofs/fileio: call erofs_onlinefolio_split() after bio_add_folio() (CVE-2025-37999)

    In the Linux kernel, the following vulnerability has been resolved:

    sch_hfsc: make hfsc_qlen_notify() idempotent (CVE-2025-38177)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2025-984 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: do proper folio cleanup when cow_file_range() failed (CVE-2024-57976)

    In the Linux kernel, the following vulnerability has been resolved:

    kernel: be more careful about dup_mmap() failures and uprobe registering (CVE-2025-21709)

    In the Linux kernel, the following vulnerability has been resolved:

    block: fix queue freeze vs limits lock order in sysfs store methods (CVE-2025-21807)

    In the Linux kernel, the following vulnerability has been resolved:

    block: mark GFP_NOIO around sysfs ->store() (CVE-2025-21817)

    In the Linux kernel, the following vulnerability has been resolved:

    iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE (CVE-2025-21833)

    In the Linux kernel, the following vulnerability has been resolved:

    net: better track kernel sockets lifetime (CVE-2025-21884)

    In the Linux kernel, the following vulnerability has been resolved:

    bnxt_en: Mask the bd_cnt field in the TX BD properly (CVE-2025-22108)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - btrfs: do proper folio cleanup when cow_file_range() failed [BUG] When testing with COW fixup marked as     BUG_ON() (this is involved with the new pin_user_pages*() change, which should not result new out-of-band     dirty pages), I hit a crash triggered by the BUG_ON() from hitting COW fixup path. This BUG_ON() happens     just after a failed btrfs_run_delalloc_range(): BTRFS error (device dm-2): failed to run delalloc range,     root 348 ino 405 folio 65536 submit_bitmap 6-15 start 90112 len 106496: -28 ------------[ cut here     ]------------ kernel BUG at fs/btrfs/extent_io.c:1444! Internal error: Oops - BUG: 00000000f2000800 [#1]     SMP CPU: 0 UID: 0 PID: 434621 Comm: kworker/u24:8 Tainted: G OE 6.12.0-rc7-custom+ #86 Hardware name: QEMU     KVM Virtual Machine, BIOS unknown 2/2/2022 Workqueue: events_unbound btrfs_async_reclaim_data_space     [btrfs] pc : extent_writepage_io+0x2d4/0x308 [btrfs] lr : extent_writepage_io+0x2d4/0x308 [btrfs] Call     trace: extent_writepage_io+0x2d4/0x308 [btrfs] extent_writepage+0x218/0x330 [btrfs]     extent_write_cache_pages+0x1d4/0x4b0 [btrfs] btrfs_writepages+0x94/0x150 [btrfs] do_writepages+0x74/0x190     filemap_fdatawrite_wbc+0x88/0xc8 start_delalloc_inodes+0x180/0x3b0 [btrfs]     btrfs_start_delalloc_roots+0x174/0x280 [btrfs] shrink_delalloc+0x114/0x280 [btrfs] flush_space+0x250/0x2f8     [btrfs] btrfs_async_reclaim_data_space+0x180/0x228 [btrfs] process_one_work+0x164/0x408     worker_thread+0x25c/0x388 kthread+0x100/0x118 ret_from_fork+0x10/0x20 Code: aa1403e1 9402f3ef aa1403e0     9402f36f (d4210000) ---[ end trace 0000000000000000 ]--- [CAUSE] That failure is mostly from     cow_file_range(), where we can hit -ENOSPC. Although the -ENOSPC is already a bug related to our space     reservation code, let's just focus on the error handling. For example, we have the following dirty range     [0, 64K) of an inode, with 4K sector size and 4K page size: 0 16K 32K 48K 64K     |///////////////////////////////////////| |#######################################| Where |///| means page     are still dirty, and |###| means the extent io tree has EXTENT_DELALLOC flag. - Enter extent_writepage()     for page 0 - Enter btrfs_run_delalloc_range() for range [0, 64K) - Enter cow_file_range() for range [0,     64K) - Function btrfs_reserve_extent() only reserved one 16K extent So we created extent map and ordered     extent for range [0, 16K) 0 16K 32K 48K 64K |////////|//////////////////////////////| |<- OE
    ->|##############################| And range [0, 16K) has its delalloc flag cleared. But since we haven't     yet submit any bio, involved 4 pages are still dirty. - Function btrfs_reserve_extent() returns with
    -ENOSPC Now we have to run error cleanup, which will clear all EXTENT_DELALLOC* flags and clear the dirty     flags for the remaining ranges: 0 16K 32K 48K 64K |////////| | | | | Note that range [0, 16K) still has     its pages dirty. - Some time later, writeback is triggered again for the range [0, 16K) since the page     range still has dirty flags. - btrfs_run_delalloc_range() will do nothing because there is no     EXTENT_DELALLOC flag. - extent_writepage_io() finds page 0 has no ordered flag Which falls into the COW     fixup path, triggering the BUG_ON(). Unfortunately this error handling bug dates back to the introduction     of btrfs. Thankfully with the abuse of COW fixup, at least it won't crash the kernel. [FIX] Instead of     immediately unlocking the extent and folios, we keep the extent and folios locked until either erroring     out or the whole delalloc range finished. When the whole delalloc range finished without error, we just     unlock the whole range with PAGE_SET_ORDERED (and PAGE_UNLOCK for !keep_locked cases) ---truncated---     (CVE-2024-57976)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
238280	Amazon Linux 2023 : bpftool, kernel6.12, kernel6.12-modules-extra (ALAS2023-2025-994)	Nessus	Amazon Linux Local Security Checks	medium
237679	Amazon Linux 2023 : bpftool, kernel6.12, kernel6.12-modules-extra (ALAS2023-2025-984)	Nessus	Amazon Linux Local Security Checks	medium
230350	Linux Distros Unpatched Vulnerability : CVE-2024-57976	Nessus	Misc.	medium

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CVE-2024-57976

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Tenable Plugins

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medium

medium