Bug 2348271 (CVE-2022-49709)

Summary: CVE-2022-49709 kernel: cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-26 03:23:38 UTC
In the Linux kernel, the following vulnerability has been resolved:

cfi: Fix __cfi_slowpath_diag RCU usage with cpuidle

RCU_NONIDLE usage during __cfi_slowpath_diag can result in an invalid
RCU state in the cpuidle code path:

  WARNING: CPU: 1 PID: 0 at kernel/rcu/tree.c:613 rcu_eqs_enter+0xe4/0x138
  ...
  Call trace:
    rcu_eqs_enter+0xe4/0x138
    rcu_idle_enter+0xa8/0x100
    cpuidle_enter_state+0x154/0x3a8
    cpuidle_enter+0x3c/0x58
    do_idle.llvm.6590768638138871020+0x1f4/0x2ec
    cpu_startup_entry+0x28/0x2c
    secondary_start_kernel+0x1b8/0x220
    __secondary_switched+0x94/0x98

Instead, call rcu_irq_enter/exit to wake up RCU only when needed and
disable interrupts for the entire CFI shadow/module check when we do.

Comment 1 Avinash Hanwate 2025-02-26 11:31:19 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022630-CVE-2022-49709-f834@gregkh/T

Comment 4 Avinash Hanwate 2025-02-26 16:00:11 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022630-CVE-2022-49709-f834@gregkh/T