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TI-2026-45368 Aliases CVE-2026-63802GHSA-22rm-57qw-fv2w

blk-cgroup: fix UAF in __blkcg_rstat_flush()

Priority LOW 35CWE-362Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 31 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix UAF in __blkcg_rstat_flush() When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkg's __blkcg_rstat_flush() removes another blkg's iostat entries via llist_del_all(). The second blkg sees an empty list and proceeds to free itself while the first is still iterating over its entries. Move the flush from __blkg_release() (RCU callback) to blkg_release() (before call_rcu). This ensures the RCU grace period waits for any concurrent flush's rcu_read_lock() section to complete before freeing.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00102 0th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.4, 6.6.144, 6.12.95 +3Red Hat: 10 advisoriesRed Hat: 31 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux6.3.9 to before 6.46.4Patch availableCNA
LinuxLinux6.4 and later6.6.144, 6.12.95, 6.18.38, 7.1.3, 7.2Patch availableCNA
  • Linux VendorLinux Affected 6.3.9 to before 6.4 Fixed in 6.4 Patch available CNA
  • Linux VendorLinux Affected 6.4 and later Fixed in 6.6.144, 6.12.95, 6.18.38, 7.1.3, 7.2 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*6.3.9 to before 6.4; 6.4.1 to before 6.6.144; 6.7 to before 6.12.95; 6.13 to before 6.18.38; 6.19 to before 7.1.3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.4:-:*:*:*:*:*:*6.4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.4:rc7:*:*:*:*:*:*6.4 rc7VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.3.9 to before 6.4; 6.4.1 to before 6.6.144; 6.7 to before 6.12.95; 6.13 to before 6.18.38; 6.19 to before 7.1.3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.4:-:*:*:*:*:*:* Versions 6.4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.4:rc7:*:*:*:*:*:* Versions 6.4 rc7 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.4
  • Fix · CNA Linux (Linux) Fixed in 6.6.144, 6.12.95, 6.18.38, 7.1.3, 7.2

Red Hat 10 advisories

  • RHSA-2026:93047 Released 2026-10-30 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt-5.14.0-284.200.1.rt14.485.el9_2, kernel-rt-core-5.14.0-284.200.1.rt14.485.el9_2, kernel-rt-debug-5.14.0-284.200.1.rt14.485.el9_2 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt-5.14.0-284.200.1.rt14.485.el9_2, kernel-rt-core-5.14.0-284.200.1.rt14.485.el9_2, kernel-rt-debug-5.14.0-284.200.1.rt14.485.el9_2 +11
  • RHSA-2026:92993 Released 2026-10-30 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) kernel-64k-debug-devel-5.14.0-284.200.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.200.1.el9_2, kernel-64k-devel-5.14.0-284.200.1.el9_2 +10
    • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool-7.0.0-284.200.1.el9_2, kernel-5.14.0-284.200.1.el9_2, kernel-64k-5.14.0-284.200.1.el9_2 +29
  • RHSA-2026:91492 Released 2026-10-28 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) kernel-tools-libs-devel-5.14.0-570.152.1.el9_6, libperf-5.14.0-570.152.1.el9_6
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) kernel-64k-debug-devel-5.14.0-570.152.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.152.1.el9_6, kernel-64k-devel-5.14.0-570.152.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel-5.14.0-570.152.1.el9_6, kernel-64k-5.14.0-570.152.1.el9_6, kernel-64k-core-5.14.0-570.152.1.el9_6 +28
    • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt-5.14.0-570.152.1.el9_6, kernel-rt-64k-5.14.0-570.152.1.el9_6, kernel-rt-64k-core-5.14.0-570.152.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt-5.14.0-570.152.1.el9_6, kernel-rt-core-5.14.0-570.152.1.el9_6, kernel-rt-debug-5.14.0-570.152.1.el9_6 +11
Show 7 more Red Hat advisories
  • RHSA-2026:91489 Released 2026-10-28 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) kernel-64k-debug-devel-5.14.0-427.158.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.158.1.el9_4, kernel-64k-devel-5.14.0-427.158.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool-7.3.0-427.158.1.el9_4, kernel-5.14.0-427.158.1.el9_4, kernel-64k-5.14.0-427.158.1.el9_4 +29
    • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt-5.14.0-427.158.1.el9_4, kernel-rt-core-5.14.0-427.158.1.el9_4, kernel-rt-debug-5.14.0-427.158.1.el9_4 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt-5.14.0-427.158.1.el9_4, kernel-rt-core-5.14.0-427.158.1.el9_4, kernel-rt-debug-5.14.0-427.158.1.el9_4 +11
  • RHSA-2026:84793 Released 2026-10-19 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bpftool-4.18.0-477.175.1.el8_8, kernel-4.18.0-477.175.1.el8_8, kernel-abi-stablelists-4.18.0-477.175.1.el8_8 +14
    • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bpftool-4.18.0-477.175.1.el8_8, kernel-4.18.0-477.175.1.el8_8, kernel-abi-stablelists-4.18.0-477.175.1.el8_8 +14
  • RHSA-2026:79783 Released 2026-10-09 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bpftool-4.18.0-372.221.1.el8_6, kernel-4.18.0-372.221.1.el8_6, kernel-abi-stablelists-4.18.0-372.221.1.el8_6 +14
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) bpftool-4.18.0-372.221.1.el8_6, kernel-4.18.0-372.221.1.el8_6, kernel-abi-stablelists-4.18.0-372.221.1.el8_6 +14
  • RHSA-2026:71232 Released 2026-09-24 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.51.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.51.1.el9_8, kernel-64k-devel-5.14.0-687.51.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.51.1.el9_8, kernel-64k-5.14.0-687.51.1.el9_8, kernel-64k-core-5.14.0-687.51.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.51.1.el9_8, libperf-5.14.0-687.51.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.51.1.el9_8, kernel-rt-64k-5.14.0-687.51.1.el9_8, kernel-rt-64k-core-5.14.0-687.51.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.51.1.el9_8, kernel-rt-core-5.14.0-687.51.1.el9_8, kernel-rt-debug-5.14.0-687.51.1.el9_8 +9
  • RHSA-2026:71233 Released 2026-09-24 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.59.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.59.1.el10_2, kernel-64k-devel-6.12.0-211.59.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.59.1.el10_2, kernel-64k-6.12.0-211.59.1.el10_2, kernel-64k-core-6.12.0-211.59.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.59.1.el10_2, libperf-6.12.0-211.59.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.59.1.el10_2, kernel-rt-64k-6.12.0-211.59.1.el10_2, kernel-rt-64k-core-6.12.0-211.59.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.59.1.el10_2, kernel-rt-core-6.12.0-211.59.1.el10_2, kernel-rt-debug-6.12.0-211.59.1.el10_2 +9
  • RHSA-2026:67468 Released 2026-09-15 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.163.1.el8_10, kernel-4.18.0-553.163.1.el8_10, kernel-abi-stablelists-4.18.0-553.163.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.163.1.el8_10
  • RHSA-2026:67469 Released 2026-09-15 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-core-4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-debug-4.18.0-553.163.1.rt7.504.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-core-4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-debug-4.18.0-553.163.1.rt7.504.el8_10 +7

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:71233
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:71232
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:92993
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:91489
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:71233
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:67468
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:71232
Red Hat Enterprise Linux BaseOS AUS (v.8.6)Fixed RHSA-2026:79783
Red Hat Enterprise Linux BaseOS E4S (v.8.8)Fixed RHSA-2026:84793
Red Hat Enterprise Linux BaseOS E4S (v.9.2)Fixed RHSA-2026:92993
Red Hat Enterprise Linux BaseOS E4S (v.9.4)Fixed RHSA-2026:91489
Red Hat Enterprise Linux BaseOS EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)Fixed RHSA-2026:79783
Red Hat Enterprise Linux BaseOS TUS (v.8.8)Fixed RHSA-2026:84793
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:67468
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:71233
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:71232
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:67469
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:67469
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:71233
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:71232
Red Hat Enterprise Linux Real Time E4S (v.9.2)Fixed RHSA-2026:93047
Red Hat Enterprise Linux Real Time E4S (v.9.4)Fixed RHSA-2026:91489
Red Hat Enterprise Linux Real Time EUS (v.9.6)Fixed RHSA-2026:91492
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:71233
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:71232
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)Fixed RHSA-2026:93047
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)Fixed RHSA-2026:91489
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)Fixed RHSA-2026:91492
Not affected: 1 product
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63802
  2. 2026-10-03 Alias added: GHSA-22rm-57qw-fv2w
  3. 2026-10-09 Fix available: RHSA-2026:79783 · Red Hat
  4. 2026-10-09 Fix available: Red Hat Enterprise Linux BaseOS AUS (v.8.6), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) · Red Hat
  5. 2026-10-16 CISA SSVC decision points changed
  6. 2026-10-19 Weakness changed · CISA ADP
  7. 2026-10-20 Fix available: RHSA-2026:84793 · Red Hat
  8. 2026-10-20 Fix available: Red Hat Enterprise Linux BaseOS E4S (v.8.8), Red Hat Enterprise Linux BaseOS TUS (v.8.8) · Red Hat
  9. 2026-10-29 Fix available: RHSA-2026:91489 · Red Hat
  10. 2026-10-30 Fix available: RHSA-2026:91492 · Red Hat
  11. 2026-10-30 Fix available: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux AppStream EUS (v.9.6) +6 · Red Hat
  12. 2026-10-30 Fix available: RHSA-2026:93047 · Red Hat
  13. 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2), Red Hat Enterprise Linux Real Time E4S (v.9.2) +1 · Red Hat
  14. 2026-10-31 Fix available: RHSA-2026:92993 · Red Hat

References

Patch 5

  • 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-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
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

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