Messages in this thread | | | Date | Tue, 4 Jan 2022 11:50:33 +0800 | From | Li Fei1 <> | Subject | Re: [PATCH] virt: acrn: fix a memory leak bug in acrn_dev_ioctl() |
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On Tue, Jan 04, 2022 at 11:45:01AM +0800, Zhou Qingyang wrote: > In acrn_dev_ioctl(), vm_param is not released or passed out on the > error path of "if ((vm_param->reserved0 | vm_param->reserved1) != 0)", > which could lead to a memory leak. > > Fix this bug by adding a kfree of vm_param on the error path. > > This bug was found by a static analyzer. > > Builds with CONFIG_ACRN_GUEST=y, CONFIG_ACRN_HSM=y show no new warnings, > and our static analyzer no longer warns about this code. > > Fixes: 9c5137aedd11 (“9c5137aedd11 virt: acrn: Introduce VM management interfaces”) > Signed-off-by: Zhou Qingyang <zhou1615@umn.edu> > --- > The analysis employs differential checking to identify inconsistent > security operations (e.g., checks or kfrees) between two code paths > and confirms that the inconsistent operations are not recovered in > the current function or the callers, so they constitute bugs. > > Note that, as a bug found by static analysis, it can be a false > positive or hard to trigger. Multiple researchers have cross-reviewed > the bug. > > Changes in v2: > - Fix the same bug in ACRN_IOCTL_SET_VCPU_REGS. >
Signed-off-by: Fei Li <fei1.li@intel.com>
Thanks a lot.
> drivers/virt/acrn/hsm.c | 24 +++++++++++++++++------- > 1 file changed, 17 insertions(+), 7 deletions(-) > > diff --git a/drivers/virt/acrn/hsm.c b/drivers/virt/acrn/hsm.c > index 5419794fccf1..7a8f722f431c 100644 > --- a/drivers/virt/acrn/hsm.c > +++ b/drivers/virt/acrn/hsm.c > @@ -136,9 +136,11 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd, > if (IS_ERR(vm_param)) > return PTR_ERR(vm_param); > > - if ((vm_param->reserved0 | vm_param->reserved1) != 0) > - return -EINVAL; > - > + if ((vm_param->reserved0 | vm_param->reserved1) != 0) { > + ret = -EINVAL; > + kfree(vm_param); > + break; > + } > vm = acrn_vm_create(vm, vm_param); > if (!vm) { > ret = -EINVAL; > @@ -182,21 +184,29 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd, > return PTR_ERR(cpu_regs); > > for (i = 0; i < ARRAY_SIZE(cpu_regs->reserved); i++) > - if (cpu_regs->reserved[i]) > + if (cpu_regs->reserved[i]) { > + kfree(cpu_regs); > return -EINVAL; > + } > > for (i = 0; i < ARRAY_SIZE(cpu_regs->vcpu_regs.reserved_32); i++) > - if (cpu_regs->vcpu_regs.reserved_32[i]) > + if (cpu_regs->vcpu_regs.reserved_32[i]) { > + kfree(cpu_regs); > return -EINVAL; > + } > > for (i = 0; i < ARRAY_SIZE(cpu_regs->vcpu_regs.reserved_64); i++) > - if (cpu_regs->vcpu_regs.reserved_64[i]) > + if (cpu_regs->vcpu_regs.reserved_64[i]) { > + kfree(cpu_regs); > return -EINVAL; > + } > > for (i = 0; i < ARRAY_SIZE(cpu_regs->vcpu_regs.gdt.reserved); i++) > if (cpu_regs->vcpu_regs.gdt.reserved[i] | > - cpu_regs->vcpu_regs.idt.reserved[i]) > + cpu_regs->vcpu_regs.idt.reserved[i]) { > + kfree(cpu_regs); > return -EINVAL; > + } > > ret = hcall_set_vcpu_regs(vm->vmid, virt_to_phys(cpu_regs)); > if (ret < 0) > -- > 2.25.1 >
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