On 12.11.21 08:01, Baoquan He wrote:
> On 11/11/21 at 08:18pm, David Hildenbrand wrote:
>> To clear a user buffer we cannot simply use memset, we have to use
>> clear_user(). Using a kernel config based on rawhide Fedora and a
>> virtio-mem device that registers a vmcore_cb, I can easily trigger:
>
On 12.11.21 04:30, Baoquan He wrote:
> On 11/11/21 at 08:22pm, David Hildenbrand wrote:
>> In commit cc5f2704c934 ("proc/vmcore: convert oldmem_pfn_is_ram callback
>> to more generic vmcore callbacks"), we added detection of surprise
>> vmcore_cb unregistration after the vmcore was already opened.
On 11/12/21 at 09:28am, David Hildenbrand wrote:
> On 12.11.21 04:30, Baoquan He wrote:
> > On 11/11/21 at 08:22pm, David Hildenbrand wrote:
> >> In commit cc5f2704c934 ("proc/vmcore: convert oldmem_pfn_is_ram callback
> >> to more generic vmcore callbacks"), we added detection of surprise
> >> vmc
On 11/12/21 at 09:16am, David Hildenbrand wrote:
> On 12.11.21 08:01, Baoquan He wrote:
> > On 11/11/21 at 08:18pm, David Hildenbrand wrote:
> >> To clear a user buffer we cannot simply use memset, we have to use
> >> clear_user(). Using a kernel config based on rawhide Fedora and a
> >> virtio-mem
> > "that allows supervisor mode programs to optionally set user-space
> > memory mappings so that access to those mappings from supervisor mode
> > will cause a trap. This makes it harder for malicious programs to
> > "trick" the kernel into using instructions or data from a user-space
> > program
To clear a user buffer we cannot simply use memset, we have to use
clear_user(). With a virtio-mem device that registers a vmcore_cb and has
some logically unplugged memory inside an added Linux memory block, I can
easily trigger a BUG by copying the vmcore via "cp":
[ 11.327580] systemd[1]: Sta
On 11/12/21 at 10:08am, David Hildenbrand wrote:
> > > "that allows supervisor mode programs to optionally set user-space
> > > memory mappings so that access to those mappings from supervisor mode
> > > will cause a trap. This makes it harder for malicious programs to
> > > "trick" the kernel into
On Mon, Sep 13, 2021 at 05:55:59PM +0200, Joerg Roedel wrote:
> From: Joerg Roedel
>
> GHCB protocol version 2 adds the MSR-based AP-reset-hold VMGEXIT which
> does not need a GHCB. Use that to park APs in 16-bit protected mode on
> the AP Jump Table.
>
> Signed-off-by: Joerg Roedel
> ---
> ar
