cbcvebase.
CVE-2021-47632
published 2025-02-26

CVE-2021-47632: In the Linux kernel, the following vulnerability has been resolved: powerpc/set_memory: Avoid spinlock recursion in change_page_attr() Commit 1f9ad21c3b38…

PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.18%
8.1th percentile
In the Linux kernel, the following vulnerability has been resolved: powerpc/set_memory: Avoid spinlock recursion in change_page_attr() Commit 1f9ad21c3b38 ("powerpc/mm: Implement set_memory() routines") included a spin_lock() to change_page_attr() in order to safely perform the three step operations. But then commit 9f7853d7609d ("powerpc/mm: Fix set_memory_*() against concurrent accesses") modify it to use pte_update() and do the operation safely against concurrent access. In the meantime, Maxime reported some spinlock recursion. [ 15.351649] BUG: spinlock recursion on CPU#0, kworker/0:2/217 [ 15.357540] lock: init_mm+0x3c/0x420, .magic: dead4ead, .owner: kworker/0:2/217, .owner_cpu: 0 [ 15.366563] CPU: 0 PID: 217 Comm: kworker/0:2 Not tainted 5.15.0+ #523 [ 15.373350] Workqueue: events do_free_init [ 15.377615] Call Trace: [ 15.380232] [e4105ac0] [800946a4] do_raw_spin_lock+0xf8/0x120 (unreliable) [ 15.387340] [e4105ae0] [8001f4ec] change_page_attr+0x40/0x1d4 [ 15.393413] [e4105b10] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.400009] [e4105b60] [80169620] free_pcp_prepare+0x1e4/0x4a0 [ 15.406045] [e4105ba0] [8016c5a0] free_unref_page+0x40/0x2b8 [ 15.411979] [e4105be0] [8018724c] kasan_depopulate_vmalloc_pte+0x6c/0x94 [ 15.418989] [e4105c00] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.425451] [e4105c50] [80187834] kasan_release_vmalloc+0xbc/0x134 [ 15.431898] [e4105c70] [8015f7a8] __purge_vmap_area_lazy+0x4e4/0xdd8 [ 15.438560] [e4105d30] [80160d10] _vm_unmap_aliases.part.0+0x17c/0x24c [ 15.445283] [e4105d60] [801642d0] __vunmap+0x2f0/0x5c8 [ 15.450684] [e4105db0] [800e32d0] do_free_init+0x68/0x94 [ 15.456181] [e4105dd0] [8005d094] process_one_work+0x4bc/0x7b8 [ 15.462283] [e4105e90] [8005d614] worker_thread+0x284/0x6e8 [ 15.468227] [e4105f00] [8006aaec] kthread+0x1f0/0x210 [ 15.473489] [e4105f40] [80017148] ret_from_kernel_thread+0x14/0x1c Remove the read / modify / write sequence to make the operation atomic and remove the spin_lock() in change_p

Affected

12 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 5.17.3-1 (bookworm)linux 5.17.3-1 (bookworm)
linuxlinux
linuxlinux>= 1f9ad21c3b384a8f16d8c46845a48a01d281a603 < 6def4eaf0391f24be541633a954c0e4876858b1e6def4eaf0391f24be541633a954c0e4876858b1e
linuxlinux>= 1f9ad21c3b384a8f16d8c46845a48a01d281a603 < 96917107e67846f1d959ed03be281048efad14c596917107e67846f1d959ed03be281048efad14c5
linuxlinux>= 1f9ad21c3b384a8f16d8c46845a48a01d281a603 < 6ebe5ca2cbe438a688f2ae238ef5a0b0b5f3468a6ebe5ca2cbe438a688f2ae238ef5a0b0b5f3468a
linuxlinux>= 1f9ad21c3b384a8f16d8c46845a48a01d281a603 < a4c182ecf33584b9b2d1aa9dad073014a504c01fa4c182ecf33584b9b2d1aa9dad073014a504c01f
linuxlinux_kernel< 5.15.345.15.34
linuxlinux_kernel>= 0 < 5.17.3-15.17.3-1
linuxlinux_kernel>= 0 < 5.17.3-15.17.3-1
linuxlinux_kernel>= 0 < 5.17.3-15.17.3-1
linuxlinux_kernel>= 5.16 < 5.16.205.16.20
linuxlinux_kernel>= 5.17 < 5.17.35.17.3

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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