Read the docs
TI-2026-52354 Aliases CVE-2026-74571GHSA-2vh7-793m-f7hf

btrfs: skip global block reserve accounting for rescue mounts

Priority LOW 22Published · Updated

Key facts

Attack vector
—
Privileges required
—
User interaction
—
Attack complexity
—
Impact type
—
Confidentiality · integrity · availability
—
Fix status
Partial Red Hat: 2 without a fix

No CVSS vector from any source. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: btrfs: skip global block reserve accounting for rescue mounts [BUG] Mounting with rescue=ibadroots after corrupting the block group tree root triggers a NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 0000000000000100 RIP: 0010:btrfs_update_global_block_rsv+0x9d/0x1c0 [btrfs] Call Trace: fill_dummy_bgs+0xd4/0x120 [btrfs] open_ctree+0xc6e/0x1ca0 [btrfs] btrfs_get_tree+0x50d/0xa40 [btrfs] The same crash occurs with a corrupted raid stripe tree root, via btrfs_read_block_groups() instead of fill_dummy_bgs(). [CAUSE] With rescue=ibadroots, btrfs_read_roots() allows the mount to continue when either root cannot be read, leaving the corresponding root pointer NULL while its on-disk feature bit remains set. btrfs_update_global_block_rsv() then dereferences the missing root based on the feature bit alone. [FIX] Rescue mounts are fully read-only and cannot start transactions, so the global reserve is never consumed. Under btrfs_is_full_ro(), mark the reserve as full and return before performing the accounting. And since we need to check if the fs is mount fully RO, export fs_is_full_ro() as btrfs_is_full_ro(), and move it to fs.h. [ Squash the fs_is_full_ro() export commit into this one. ]

Why it matters now

EPSS 0.00204 10th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.1.191, 6.5, 6.6.160 +4Red Hat: 2 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.1.43 to before 6.1.191; 6.4.8 to before 6.56.1.191, 6.5Patch availableCNA
LinuxLinux6.5 and later6.1.191, 6.6.160, 6.12.114, 6.18.57, 7.1.8, 7.2Patch availableCNA
  • Linux VendorLinux Affected 6.1.43 to before 6.1.191; 6.4.8 to before 6.5 Fixed in 6.1.191, 6.5 Patch available CNA
  • Linux VendorLinux Affected 6.5 and later Fixed in 6.1.191, 6.6.160, 6.12.114, 6.18.57, 7.1.8, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*——Linux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.5
  • Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.114, 6.18.57, 7.1.8, 7.2

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Not affected: 3 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-74571
  2. 2026-10-03 Alias added: GHSA-2vh7-793m-f7hf
  3. 2026-10-16 Fix available: Linux/[email protected], Linux/Linux@969a96479add6bd42d7f7241f99f27b31571a953 · CNA
  4. 2026-10-16 1 new reference · CNA
  5. 2026-10-21 Fix available: Linux/Linux@3a69fae2371a5ee190d4c4bbe5304a753558c1c6, Linux/[email protected], Linux/[email protected] +1 · CNA
  6. 2026-10-21 2 new references · CNA
  7. 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@aa72cc4675240ab6b01ec72ac6a1fe832e715569 · CNA
  8. 2026-10-30 1 new reference · CNA

References

Other 6

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences