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Linux KernelOperating system · Linux

CVE-2026-23219

MEDIUM · 5.5 CVSS v3.1 Published 2026-02-18
Fix available
A fix is available. Upgrade to 6.12.70 / 6.18.10 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: mm/slab: Add alloc_tagging_slab_free_hook for memcg_alloc_abort_single When CONFIG_MEM_ALLOC_PROFILING_DEBUG is enabled, the following warning may be noticed: [ 3959.023862] ------------[ cut here ]------------ [ 3959.023891] alloc_tag was not cleared (got tag for lib/xarray.c:378) [ 3959.023947] WARNING: ./include/linux/alloc_tag.h:155 at alloc_tag_add+0x128/0x178, CPU#6: mkfs.ntfs/113998 [ 3959.023978] Modules linked in: dns_resolver tun brd overlay exfat btrfs blake2b libblake2b xor xor_neon raid6_pq loop sctp ip6_udp_tunnel udp_tunnel ext4 crc16 mbcache jbd2 rfkill sunrpc vfat fat sg fuse nfnetlink sr_mod virtio_gpu cdrom drm_client_lib virtio_dma_buf drm_shmem_helper drm_kms_helper ghash_ce drm sm4 backlight virtio_net net_failover virtio_scsi failover virtio_console virtio_blk virtio_mmio dm_mirror dm_region_hash dm_log dm_multipath dm_mod i2c_dev aes_neon_bs aes_ce_blk [last unloaded: hwpoison_inject] [ 3959.024170] CPU: 6 UID: 0 PID: 113998 Comm: mkfs.ntfs Kdump: loaded Tainted: G W 6.19.0-rc7+ #7 PREEMPT(voluntary) [ 3959.024182] Tainted: [W]=WARN [ 3959.024186] Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 [ 3959.024192] pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 3959.024199] pc : alloc_tag_add+0x128/0x178 [ 3959.024207] lr : alloc_tag_add+0x128/0x178 [ 3959.024214] sp : ffff80008b696d60 [ 3959.024219] x29: ffff80008b696d60 x28: 0000000000000000 x27: 0000000000000240 [ 3959.024232] x26: 0000000000000000 x25: 0000000000000240 x24: ffff800085d17860 [ 3959.024245] x23: 0000000000402800 x22: ffff0000c0012dc0 x21: 00000000000002d0 [ 3959.024257] x20: ffff0000e6ef3318 x19: ffff800085ae0410 x18: 0000000000000000 [ 3959.024269] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 3959.024281] x14: 0000000000000000 x13: 0000000000000001 x12: ffff600064101293 [ 3959.024292] x11: 1fffe00064101292 x10: ffff600064101292 x9 : dfff800000000000 [ 3959.024305] x8 : 00009fff9befed6e x7 : ffff000320809493 x6 : 0000000000000001 [ 3959.024316] x5 : ffff000320809490 x4 : ffff600064101293 x3 : ffff800080691838 [ 3959.024328] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0000d5bcd640 [ 3959.024340] Call trace: [ 3959.024346] alloc_tag_add+0x128/0x178 (P) [ 3959.024355] __alloc_tagging_slab_alloc_hook+0x11c/0x1a8 [ 3959.024362] kmem_cache_alloc_lru_noprof+0x1b8/0x5e8 [ 3959.024369] xas_alloc+0x304/0x4f0 [ 3959.024381] xas_create+0x1e0/0x4a0 [ 3959.024388] xas_store+0x68/0xda8 [ 3959.024395] __filemap_add_folio+0x5b0/0xbd8 [ 3959.024409] filemap_add_folio+0x16c/0x7e0 [ 3959.024416] __filemap_get_folio_mpol+0x2dc/0x9e8 [ 3959.024424] iomap_get_folio+0xfc/0x180 [ 3959.024435] __iomap_get_folio+0x2f8/0x4b8 [ 3959.024441] iomap_write_begin+0x198/0xc18 [ 3959.024448] iomap_write_iter+0x2ec/0x8f8 [ 3959.024454] iomap_file_buffered_write+0x19c/0x290 [ 3959.024461] blkdev_write_iter+0x38c/0x978 [ 3959.024470] vfs_write+0x4d4/0x928 [ 3959.024482] ksys_write+0xfc/0x1f8 [ 3959.024489] __arm64_sys_write+0x74/0xb0 [ 3959.024496] invoke_syscall+0xd4/0x258 [ 3959.024507] el0_svc_common.constprop.0+0xb4/0x240 [ 3959.024514] do_el0_svc+0x48/0x68 [ 3959.024520] el0_svc+0x40/0xf8 [ 3959.024526] el0t_64_sync_handler+0xa0/0xe8 [ 3959.024533] el0t_64_sync+0x1ac/0x1b0 [ 3959.024540] ---[ end trace 0000000000000000 ]--- When __memcg_slab_post_alloc_hook() fails, there are two different free paths depending on whether size == 1 or size != 1. In the kmem_cache_free_bulk() path, we do call alloc_tagging_slab_free_hook(). However, in memcg_alloc_abort_single() we don't, the above warning will be triggered on the next allocation. Therefore, add alloc_tagging_slab_free_hook() to the memcg_alloc_abort_single() path.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 6.10, < 6.12.70>= 6.13, < 6.18.10= 6.19

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.12.70 / 6.18.10 or later
Fixed in 6.12.706.18.10
Vendor patch git.kernel.org →
Recommended fix High confidence

Linux Kernel 6.12.70+ (for 6.12.x), 6.18.10+ (for 6.13-6.18.x), or 6.20+ (for 6.19.x)

  1. 1. Identify the current running kernel version using `uname -r`
  2. 2. Determine the appropriate fixed kernel version for your distribution: For 6.12.x series, upgrade to >= 6.12.70; For 6.13.x through 6.18.x series, upgrade to >= 6.18.10; For 6.19.x, upgrade to a version > 6.19 (or wait for 6.20 stable)
  3. 3. Update the package repository metadata: `sudo apt-get update` (Debian/Ubuntu) or `sudo yum check-update` (RHEL/CentOS)
  4. 4. Install the new kernel package: `sudo apt-get install linux-image-<version>` or `sudo yum install kernel-<version>`
  5. 5. Reboot the system to load the new kernel: `sudo reboot`
  6. 6. After reboot, verify the kernel version is fixed: `uname -r`
  7. 7. Confirm the fix is applied by checking that the warning no longer appears in kernel logs: `dmesg | grep -i 'alloc_tag was not cleared'`
Caveat Kernel upgrades may require system reboot and could have compatibility implications with custom modules or specific hardware drivers; ensure backups and test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,600. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

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Peer-ranked notes from engineers who’ve handled CVE-2026-23219 in production — separate from our analysis above.

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