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SUSE: CVE-2021-47454: SUSE Linux Security Advisory

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SUSE: CVE-2021-47454: SUSE Linux Security Advisory

Severity
4
CVSS
(AV:L/AC:M/Au:N/C:P/I:P/A:P)
Published
05/22/2024
Created
08/16/2024
Added
08/09/2024
Modified
08/09/2024

Description

In the Linux kernel, the following vulnerability has been resolved: powerpc/smp: do not decrement idle task preempt count in CPU offline With PREEMPT_COUNT=y, when a CPU is offlined and then onlined again, we get: BUG: scheduling while atomic: swapper/1/0/0x00000000 no locks held by swapper/1/0. CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.15.0-rc2+ #100 Call Trace: dump_stack_lvl+0xac/0x108 __schedule_bug+0xac/0xe0 __schedule+0xcf8/0x10d0 schedule_idle+0x3c/0x70 do_idle+0x2d8/0x4a0 cpu_startup_entry+0x38/0x40 start_secondary+0x2ec/0x3a0 start_secondary_prolog+0x10/0x14 This is because powerpc's arch_cpu_idle_dead() decrements the idle task's preempt count, for reasons explained in commit a7c2bb8279d2 ("powerpc: Re-enable preemption before cpu_die()"), specifically "start_secondary() expects a preempt_count() of 0." However, since commit 2c669ef6979c ("powerpc/preempt: Don't touch the idle task's preempt_count during hotplug") and commit f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled"), that justification no longer holds. The idle task isn't supposed to re-enable preemption, so remove the vestigial preempt_enable() from the CPU offline path. Tested with pseries and powernv in qemu, and pseries on PowerVM.

Solution(s)

  • suse-upgrade-cluster-md-kmp-64kb
  • suse-upgrade-cluster-md-kmp-azure
  • suse-upgrade-cluster-md-kmp-default
  • suse-upgrade-cluster-md-kmp-rt
  • suse-upgrade-dlm-kmp-64kb
  • suse-upgrade-dlm-kmp-azure
  • suse-upgrade-dlm-kmp-default
  • suse-upgrade-dlm-kmp-rt
  • suse-upgrade-dtb-allwinner
  • suse-upgrade-dtb-altera
  • suse-upgrade-dtb-amazon
  • suse-upgrade-dtb-amd
  • suse-upgrade-dtb-amlogic
  • suse-upgrade-dtb-apm
  • suse-upgrade-dtb-apple
  • suse-upgrade-dtb-arm
  • suse-upgrade-dtb-broadcom
  • suse-upgrade-dtb-cavium
  • suse-upgrade-dtb-exynos
  • suse-upgrade-dtb-freescale
  • suse-upgrade-dtb-hisilicon
  • suse-upgrade-dtb-lg
  • suse-upgrade-dtb-marvell
  • suse-upgrade-dtb-mediatek
  • suse-upgrade-dtb-nvidia
  • suse-upgrade-dtb-qcom
  • suse-upgrade-dtb-renesas
  • suse-upgrade-dtb-rockchip
  • suse-upgrade-dtb-socionext
  • suse-upgrade-dtb-sprd
  • suse-upgrade-dtb-xilinx
  • suse-upgrade-gfs2-kmp-64kb
  • suse-upgrade-gfs2-kmp-azure
  • suse-upgrade-gfs2-kmp-default
  • suse-upgrade-gfs2-kmp-rt
  • suse-upgrade-kernel-64kb
  • suse-upgrade-kernel-64kb-devel
  • suse-upgrade-kernel-64kb-extra
  • suse-upgrade-kernel-64kb-livepatch-devel
  • suse-upgrade-kernel-64kb-optional
  • suse-upgrade-kernel-azure
  • suse-upgrade-kernel-azure-devel
  • suse-upgrade-kernel-azure-extra
  • suse-upgrade-kernel-azure-livepatch-devel
  • suse-upgrade-kernel-azure-optional
  • suse-upgrade-kernel-azure-vdso
  • suse-upgrade-kernel-debug
  • suse-upgrade-kernel-debug-devel
  • suse-upgrade-kernel-debug-livepatch-devel
  • suse-upgrade-kernel-debug-vdso
  • suse-upgrade-kernel-default
  • suse-upgrade-kernel-default-base
  • suse-upgrade-kernel-default-base-rebuild
  • suse-upgrade-kernel-default-devel
  • suse-upgrade-kernel-default-extra
  • suse-upgrade-kernel-default-livepatch
  • suse-upgrade-kernel-default-livepatch-devel
  • suse-upgrade-kernel-default-optional
  • suse-upgrade-kernel-default-vdso
  • suse-upgrade-kernel-devel
  • suse-upgrade-kernel-devel-azure
  • suse-upgrade-kernel-devel-rt
  • suse-upgrade-kernel-docs
  • suse-upgrade-kernel-docs-html
  • suse-upgrade-kernel-kvmsmall
  • suse-upgrade-kernel-kvmsmall-devel
  • suse-upgrade-kernel-kvmsmall-livepatch-devel
  • suse-upgrade-kernel-kvmsmall-vdso
  • suse-upgrade-kernel-macros
  • suse-upgrade-kernel-obs-build
  • suse-upgrade-kernel-obs-qa
  • suse-upgrade-kernel-rt
  • suse-upgrade-kernel-rt-devel
  • suse-upgrade-kernel-rt-extra
  • suse-upgrade-kernel-rt-livepatch
  • suse-upgrade-kernel-rt-livepatch-devel
  • suse-upgrade-kernel-rt-optional
  • suse-upgrade-kernel-rt-vdso
  • suse-upgrade-kernel-rt_debug
  • suse-upgrade-kernel-rt_debug-devel
  • suse-upgrade-kernel-rt_debug-livepatch-devel
  • suse-upgrade-kernel-rt_debug-vdso
  • suse-upgrade-kernel-source
  • suse-upgrade-kernel-source-azure
  • suse-upgrade-kernel-source-rt
  • suse-upgrade-kernel-source-vanilla
  • suse-upgrade-kernel-syms
  • suse-upgrade-kernel-syms-azure
  • suse-upgrade-kernel-syms-rt
  • suse-upgrade-kernel-zfcpdump
  • suse-upgrade-kselftests-kmp-64kb
  • suse-upgrade-kselftests-kmp-azure
  • suse-upgrade-kselftests-kmp-default
  • suse-upgrade-kselftests-kmp-rt
  • suse-upgrade-ocfs2-kmp-64kb
  • suse-upgrade-ocfs2-kmp-azure
  • suse-upgrade-ocfs2-kmp-default
  • suse-upgrade-ocfs2-kmp-rt
  • suse-upgrade-reiserfs-kmp-64kb
  • suse-upgrade-reiserfs-kmp-azure
  • suse-upgrade-reiserfs-kmp-default
  • suse-upgrade-reiserfs-kmp-rt

References

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