On Fri, Feb 14, 2020 at 09:32:30AM +0100, Borislav Petkov wrote:
On Fri, Feb 14, 2020 at 09:28:01AM +0100, Borislav Petkov wrote:
From: Thomas Gleixner tglx@linutronix.de
Accessing the MCA thresholding controls in sysfs concurrently with CPU hotplug can lead to a couple of KASAN-reported issues:
BUG: KASAN: use-after-free in sysfs_file_ops+0x155/0x180 Read of size 8 at addr ffff888367578940 by task grep/4019
and
BUG: KASAN: use-after-free in show_error_count+0x15c/0x180 Read of size 2 at addr ffff888368a05514 by task grep/4454
for example. Both result from the fact that the threshold block creation/teardown code frees the descriptor memory itself instead of defining proper ->release function and leaving it to the driver core to take care of that, after all sysfs accesses have completed.
Do that and get rid of the custom freeing code, fixing the above UAFs in the process.
[ bp: write commit message. ]
Fixes: 95268664390b ("[PATCH] x86_64: mce_amd support for family 0x10 processors") Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Borislav Petkov bp@suse.de Cc: stable@vger.kernel.org
Damn git-send-email: it read out Cc: stable and added it to the Cc list. I've added
suppresscc = bodycc
to my .gitconfig.
Sorry stable guys.
Does not bother me at all, it's fine to see stuff come by that will end up in future trees, it's not noise at all. So no need to suppress stable@vger if you don't want to.
thanks,
greg k-h