Commit fdb69d40 authored by Jiakai Xu's avatar Jiakai Xu Committed by Anup Patel
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RISC-V: KVM: Fix NULL pointer dereference in SBI v0.1 SEND_IPI handler 



The SBI v0.1 SEND_IPI handler iterates over the hart mask and calls
kvm_get_vcpu_by_id() to find the target vcpu for each set bit. When a
guest provides a hart mask containing bits for non-existent vcpu_ids,
kvm_get_vcpu_by_id() returns NULL, which is then unconditionally
dereferenced by kvm_riscv_vcpu_set_interrupt(), causing a kernel crash.

Fix this by adding a NULL check before dereferencing the return value.
If the target vcpu is not found, skip it and continue processing the
remaining valid harts.

Fixes: a046c2d8 ("RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own file")
Signed-off-by: default avatarJiakai Xu <jiakaiPeanut@gmail.com>
Signed-off-by: default avatarJiakai Xu <xujiakai2025@iscas.ac.cn>
Assisted-by: OpenClaw:DeepSeek-V3.2
Reviewed-by: default avatarAnup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260517124414.420919-1-xujiakai2025@iscas.ac.cn


Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
parent 0e9d0e7a

arch/riscv/kvm/vcpu_sbi_v01.c

+2 −0
Original line number Diff line number Diff line
@@ -55,6 +55,8 @@ static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, 


		for_each_set_bit(i, &hmask, BITS_PER_LONG) {

			rvcpu = kvm_get_vcpu_by_id(vcpu->kvm, i);

			if (!rvcpu)

				continue;

			ret = kvm_riscv_vcpu_set_interrupt(rvcpu, IRQ_VS_SOFT);

			if (ret < 0)

				break;