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Linux KernelOperating system · Linux

CVE-2026-46251

HIGH · 8.4 CVSS v3.1 Published 2026-06-03
Fix available
A fix is available. Upgrade to 6.1.165 / 6.6.128 or later.
See remediation →
89/100
Remediation priority · High
No privileges 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: btrfs: fix block_group_tree dirty_list corruption When the incompat flag EXTENT_TREE_V2 is set, we unconditionally add the block group tree to the switch_commits list before calling switch_commit_roots, as we do for the tree root and the chunk root. However, the block group tree uses normal root dirty tracking and in any transaction that does an allocation and dirties a block group, the block group root will already be linked to a list by the dirty_list field and this use of list_add_tail() is invalid and corrupts the prev/next members of block_group_root->dirty_list. This is apparent on a subsequent list_del on the prev if we enable CONFIG_DEBUG_LIST: [32.1571] ------------[ cut here ]------------ [32.1572] list_del corruption. next->prev should beffff958890202538, but was ffff9588992bd538. (next=ffff958890201538) [32.1575] WARNING: lib/list_debug.c:65 at 0x0, CPU#3: sync/607 [32.1583] CPU: 3 UID: 0 PID: 607 Comm: sync Not tainted 6.18.0 #24PREEMPT(none) [32.1585] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS1.17.0-4.fc41 04/01/2014 [32.1587] RIP: 0010:__list_del_entry_valid_or_report+0x108/0x120 [32.1593] RSP: 0018:ffffaa288287fdd0 EFLAGS: 00010202 [32.1594] RAX: 0000000000000001 RBX: ffff95889326e800 RCX:ffff958890201538 [32.1596] RDX: ffff9588992bd538 RSI: ffff958890202538 RDI:ffffffff82a41e00 [32.1597] RBP: ffff958890202538 R08: ffffffff828fc1e8 R09:00000000ffffefff [32.1599] R10: ffffffff8288c200 R11: ffffffff828e4200 R12:ffff958890201538 [32.1601] R13: ffff95889326e958 R14: ffff958895c24000 R15:ffff958890202538 [32.1603] FS: 00007f0c28eb5740(0000) GS:ffff958af2bd2000(0000)knlGS:0000000000000000 [32.1605] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [32.1607] CR2: 00007f0c28e8a3cc CR3: 0000000109942005 CR4:0000000000370ef0 [32.1609] Call Trace: [32.1610] <TASK> [32.1611] switch_commit_roots+0x82/0x1d0 [btrfs] [32.1615] btrfs_commit_transaction+0x968/0x1550 [btrfs] [32.1618] ? btrfs_attach_transaction_barrier+0x23/0x60 [btrfs] [32.1621] __iterate_supers+0xe8/0x190 [32.1622] ? __pfx_sync_fs_one_sb+0x10/0x10 [32.1623] ksys_sync+0x63/0xb0 [32.1624] __do_sys_sync+0xe/0x20 [32.1625] do_syscall_64+0x73/0x450 [32.1626] entry_SYSCALL_64_after_hwframe+0x76/0x7e [32.1627] RIP: 0033:0x7f0c28d05d2b [32.1632] RSP: 002b:00007ffc9d988048 EFLAGS: 00000246 ORIG_RAX:00000000000000a2 [32.1634] RAX: ffffffffffffffda RBX: 00007ffc9d988228 RCX:00007f0c28d05d2b [32.1636] RDX: 00007f0c28e02301 RSI: 00007ffc9d989b21 RDI:00007f0c28dba90d [32.1637] RBP: 0000000000000001 R08: 0000000000000001 R09:0000000000000000 [32.1639] R10: 0000000000000000 R11: 0000000000000246 R12:000055b96572cb80 [32.1641] R13: 000055b96572b19f R14: 00007f0c28dfa434 R15:000055b96572b034 [32.1643] </TASK> [32.1644] irq event stamp: 0 [32.1644] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [32.1646] hardirqs last disabled at (0): [<ffffffff81298817>]copy_process+0xb37/0x2260 [32.1648] softirqs last enabled at (0): [<ffffffff81298817>]copy_process+0xb37/0x2260 [32.1650] softirqs last disabled at (0): [<0000000000000000>] 0x0 [32.1652] ---[ end trace 0000000000000000 ]--- Furthermore, this list corruption eventually (when we happen to add a new block group) results in getting the switch_commits and dirty_cowonly_roots lists mixed up and attempting to call update_root on the tree root which can't be found in the tree root, resulting in a transaction abort: [87.8269] BTRFS critical (device nvme1n1): unable to find root key (1 0 0) in tree 1 [87.8272] ------------[ cut here ]------------ [87.8274] BTRFS: Transaction aborted (error -117) [87.8275] WARNING: fs/btrfs/root-tree.c:153 at 0x0, CPU#4: sync/703 [87.8285] CPU: 4 UID: 0 PID: 703 Comm: sync Not tainted 6.18.0 #25 PREEMPT(none) [87.8287] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.17.0-4.fc41 0 ---truncated---

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:>= 6.0.19, < 6.1.165>= 6.2, < 6.6.128>= 6.7, < 6.12.75>= 6.13, < 6.18.14>= 6.19, < 6.19.4

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 6.1.165 / 6.6.128 / 6.12.75 or later
Fixed in 6.1.1656.6.1286.12.75
Vendor patch git.kernel.org →
Recommended fix High confidence

Upgrade to kernel 6.1.165+, 6.6.128+, 6.12.75+, or 6.18.14+ (depending on your desired stable branch)

  1. Identify your current Linux kernel version using 'uname -r'
  2. Download and install a kernel version that includes the fix: 6.1.165+, 6.6.128+, 6.12.75+, or 6.18.14+
  3. For distribution-specific systems, use your package manager to upgrade (e.g., 'apt update && apt upgrade' for Debian/Ubuntu, 'yum update' for RHEL/CentOS, or 'dnf upgrade' for Fedora)
  4. Reboot the system to load the new kernel
  5. Verify the kernel version after reboot with 'uname -r' to confirm the fix is applied

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 $1,950. 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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