[RFC PATCH 2/2] integrity: double check iint_cache was initialized
penguin-kernel at i-love.sakura.ne.jp
Mon Mar 22 07:10:59 UTC 2021
On 2021/03/20 5:03, Mimi Zohar wrote:
> The integrity's "iint_cache" is initialized at security_init(). Only
> after an IMA policy is loaded, which is initialized at late_initcall,
> is a file's integrity status stored in the "iint_cache".
> All integrity_inode_get() callers first verify that the IMA policy has
> been loaded, before calling it. Yet for some reason, it is still being
> called, causing a NULL pointer dereference.
> As reported by Dmitry Vyukov:
> in qemu:
> qemu-system-x86_64 -enable-kvm -machine q35,nvdimm -cpu
> max,migratable=off -smp 4 -m 4G,slots=4,maxmem=16G -hda
> wheezy.img -kernel arch/x86/boot/bzImage -nographic -vga std
> -soundhw all -usb -usbdevice tablet -bt hci -bt device:keyboard
> -net user,host=10.0.2.10,hostfwd=tcp::10022-:22 -net
> nic,model=virtio-net-pci -object
> -device nvdimm,id=nvdimm1,memdev=pmem1 -append "console=ttyS0
> root=/dev/sda earlyprintk=serial rodata=n oops=panic panic_on_warn=1
> panic=86400 lsm=smack numa=fake=2 nopcid dummy_hcd.num=8" -pidfile
> vm_pid -m 2G -cpu host
I tried similar command line (without "-enable-kvm" and without "-cpu host"
as I'm running from VMware, without "-soundhw all", without "-machine q35,nvdimm"
and "-device nvdimm,id=nvdimm1,memdev=pmem1" etc.) on 5.12-rc4. While I was finally
able to hit similar crash when I used "-smp 1" instead of "-smp 4", I suspect
this is not a integrity module's problem but a memory initialization/corruption
problem, for I got various different crashes (INT3) at memory allocation when
I was trimming command line options trying to reproduce the same crash.
Dmitry, do you get different crashes by changing command line arguments?
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