Re: request_module DoS

2022-05-12 Thread Luis Chamberlain
On Thu, May 12, 2022 at 10:07:26PM +1000, Michael Ellerman wrote: > Michael Ellerman writes: > > Luis Chamberlain writes: > ... > > > >> Can someone try this on ppc64le system? At this point I am not convinced > >> this issue is generic. > > > > Does your x86 system have at least 784 CPUs? > > >

Re: request_module DoS

2022-05-12 Thread Michael Ellerman
Michael Ellerman writes: > Luis Chamberlain writes: ... > >> Can someone try this on ppc64le system? At this point I am not convinced >> this issue is generic. > > Does your x86 system have at least 784 CPUs? > > I don't know where the original report came from, but the trace shows > "CPU 784",

Re: request_module DoS

2022-05-12 Thread Michael Ellerman
Luis Chamberlain writes: > On Mon, May 09, 2022 at 09:13:03AM -0700, Luis Chamberlain wrote: >> On Mon, May 09, 2022 at 09:23:39PM +1000, Michael Ellerman wrote: >> > Herbert Xu writes: >> > > Hi: >> > > >> > > There are some code paths in the kernel where you can reliably >> > > trigger a

Re: request_module DoS

2022-05-11 Thread Luis Chamberlain
On Mon, May 09, 2022 at 09:13:03AM -0700, Luis Chamberlain wrote: > On Mon, May 09, 2022 at 09:23:39PM +1000, Michael Ellerman wrote: > > Herbert Xu writes: > > > Hi: > > > > > > There are some code paths in the kernel where you can reliably > > > trigger a request_module of a non-existant

Re: request_module DoS

2022-05-09 Thread Luis Chamberlain
On Mon, May 09, 2022 at 09:23:39PM +1000, Michael Ellerman wrote: > Herbert Xu writes: > > Hi: > > > > There are some code paths in the kernel where you can reliably > > trigger a request_module of a non-existant module. For example, > > if you attempt to load a non-existent crypto algorithm, or

Re: request_module DoS

2022-05-08 Thread Luis Chamberlain
On Sat, May 07, 2022 at 12:14:47PM -0700, Luis Chamberlain wrote: > On Sat, May 07, 2022 at 01:02:20AM -0700, Luis Chamberlain wrote: > > You can try to reproduce by using adding a new test type for crypto-aegis256 > > on lib/test_kmod.c. These tests however can try something similar but other > >

Re: request_module DoS

2022-05-07 Thread Luis Chamberlain
On Sat, May 07, 2022 at 01:02:20AM -0700, Luis Chamberlain wrote: > You can try to reproduce by using adding a new test type for crypto-aegis256 > on lib/test_kmod.c. These tests however can try something similar but other > modules. > > /tools/testing/selftests/kmod/kmod.sh -t 0008 >

Re: request_module DoS

2022-05-07 Thread Luis Chamberlain
On Sat, May 07, 2022 at 07:10:23AM +, Christophe Leroy wrote: > > There are some code paths in the kernel where you can reliably > > trigger a request_module of a non-existant module. For example, > > if you attempt to load a non-existent crypto algorithm, or create > > a socket of a

Re: request_module DoS

2022-05-07 Thread Christophe Leroy
+ linuxppc list Le 07/05/2022 à 05:08, Herbert Xu a écrit : > Hi: > > There are some code paths in the kernel where you can reliably > trigger a request_module of a non-existant module. For example, > if you attempt to load a non-existent crypto algorithm, or create > a socket of a non-existent