of_numa: fix uninitialized memory nodes causing kernel panic
commit ee4d098cbc upstream.
When there are memory-only nodes (nodes without CPUs), these nodes are not
properly initialized, causing kernel panic during boot.
of_numa_init
of_numa_parse_cpu_nodes
node_set(nid, numa_nodes_parsed);
of_numa_parse_memory_nodes
In of_numa_parse_cpu_nodes, numa_nodes_parsed gets updated only for nodes
containing CPUs. Memory-only nodes should have been updated in
of_numa_parse_memory_nodes, but they weren't.
Subsequently, when free_area_init() attempts to access NODE_DATA() for
these uninitialized memory nodes, the kernel panics due to NULL pointer
dereference.
This can be reproduced on ARM64 QEMU with 1 CPU and 2 memory nodes:
qemu-system-aarch64 \
-cpu host -nographic \
-m 4G -smp 1 \
-machine virt,accel=kvm,gic-version=3,iommu=smmuv3 \
-object memory-backend-ram,size=2G,id=mem0 \
-object memory-backend-ram,size=2G,id=mem1 \
-numa node,nodeid=0,memdev=mem0 \
-numa node,nodeid=1,memdev=mem1 \
-kernel $IMAGE \
-hda $DISK \
-append "console=ttyAMA0 root=/dev/vda rw earlycon"
[ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x481fd010]
[ 0.000000] Linux version 6.17.0-rc1-00001-gabb4b3daf18c-dirty (yintirui@local) (gcc (GCC) 12.3.1, GNU ld (GNU Binutils) 2.41) #52 SMP PREEMPT Mon Aug 18 09:49:40 CST 2025
[ 0.000000] KASLR enabled
[ 0.000000] random: crng init done
[ 0.000000] Machine model: linux,dummy-virt
[ 0.000000] efi: UEFI not found.
[ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '')
[ 0.000000] printk: legacy bootconsole [pl11] enabled
[ 0.000000] OF: reserved mem: Reserved memory: No reserved-memory node in the DT
[ 0.000000] NODE_DATA(0) allocated [mem 0xbfffd9c0-0xbfffffff]
[ 0.000000] node 1 must be removed before remove section 23
[ 0.000000] Zone ranges:
[ 0.000000] DMA [mem 0x0000000040000000-0x00000000ffffffff]
[ 0.000000] DMA32 empty
[ 0.000000] Normal [mem 0x0000000100000000-0x000000013fffffff]
[ 0.000000] Movable zone start for each node
[ 0.000000] Early memory node ranges
[ 0.000000] node 0: [mem 0x0000000040000000-0x00000000bfffffff]
[ 0.000000] node 1: [mem 0x00000000c0000000-0x000000013fffffff]
[ 0.000000] Initmem setup node 0 [mem 0x0000000040000000-0x00000000bfffffff]
[ 0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0
[ 0.000000] Mem abort info:
[ 0.000000] ESR = 0x0000000096000004
[ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits
[ 0.000000] SET = 0, FnV = 0
[ 0.000000] EA = 0, S1PTW = 0
[ 0.000000] FSC = 0x04: level 0 translation fault
[ 0.000000] Data abort info:
[ 0.000000] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[ 0.000000] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[ 0.000000] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[ 0.000000] [00000000000000a0] user address but active_mm is swapper
[ 0.000000] Internal error: Oops: 0000000096000004 [#1] SMP
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.17.0-rc1-00001-g760c6dabf762-dirty #54 PREEMPT
[ 0.000000] Hardware name: linux,dummy-virt (DT)
[ 0.000000] pstate: 800000c5 (Nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 0.000000] pc : free_area_init+0x50c/0xf9c
[ 0.000000] lr : free_area_init+0x5c0/0xf9c
[ 0.000000] sp : ffffa02ca0f33c00
[ 0.000000] x29: ffffa02ca0f33cb0 x28: 0000000000000000 x27: 0000000000000000
[ 0.000000] x26: 4ec4ec4ec4ec4ec5 x25: 00000000000c0000 x24: 00000000000c0000
[ 0.000000] x23: 0000000000040000 x22: 0000000000000000 x21: ffffa02ca0f3b368
[ 0.000000] x20: ffffa02ca14c7b98 x19: 0000000000000000 x18: 0000000000000002
[ 0.000000] x17: 000000000000cacc x16: 0000000000000001 x15: 0000000000000001
[ 0.000000] x14: 0000000080000000 x13: 0000000000000018 x12: 0000000000000002
[ 0.000000] x11: ffffa02ca0fd4f00 x10: ffffa02ca14bab20 x9 : ffffa02ca14bab38
[ 0.000000] x8 : 00000000000c0000 x7 : 0000000000000001 x6 : 0000000000000002
[ 0.000000] x5 : 0000000140000000 x4 : ffffa02ca0f33c90 x3 : ffffa02ca0f33ca0
[ 0.000000] x2 : ffffa02ca0f33c98 x1 : 0000000080000000 x0 : 0000000000000001
[ 0.000000] Call trace:
[ 0.000000] free_area_init+0x50c/0xf9c (P)
[ 0.000000] bootmem_init+0x110/0x1dc
[ 0.000000] setup_arch+0x278/0x60c
[ 0.000000] start_kernel+0x70/0x748
[ 0.000000] __primary_switched+0x88/0x90
[ 0.000000] Code: d503201f b98093e0 52800016 f8607a93 (f9405260)
[ 0.000000] ---[ end trace 0000000000000000 ]---
[ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---
Link: https://lkml.kernel.org/r/20250819075510.2079961-1-yintirui@huawei.com
Fixes: 767507654c ("arch_numa: switch over to numa_memblks")
Signed-off-by: Yin Tirui <yintirui@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Chen Jun <chenjun102@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
c2daa6eb47