On Thu, 8 Feb 2024 10:56:00, Greg KH wrote: > > The input_add_uevent_modalias_var()->input_print_modalias() will add 1684 bytes > > of data to env, which will result in insufficient memory allocated to the buf > > members of env. > > What is "env"? And can you wrap your lines at 72 columns please? env is an instance of struct kobj_uevent_env. > > > Reported-and-tested-by: syzbot+8e41bb0c055b209ebbf4@xxxxxxxxxxxxxxxxxxxxxxxxx > > Signed-off-by: Edward Adam Davis <eadavis@xxxxxx> > > --- > > include/linux/kobject.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/include/linux/kobject.h b/include/linux/kobject.h > > index c30affcc43b4..74b37b6459cd 100644 > > --- a/include/linux/kobject.h > > +++ b/include/linux/kobject.h > > @@ -30,7 +30,7 @@ > > > > #define UEVENT_HELPER_PATH_LEN 256 > > #define UEVENT_NUM_ENVP 64 /* number of env pointers */ > > -#define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */ > > +#define UEVENT_BUFFER_SIZE 2560 /* buffer for the variables */ > > That's an odd number, why that? Why not just a page? What happens if > some other path wants more? An increase of 512 bytes is sufficient for the current issue. Do not consider the problem of hypothetical existence. > > And what's causing the input stack to have so many variables all of a > sudden, what changed to cause this? Is this a bugfix for a specific > commit that needs to be backported to older kernels? Why did this > buffer size all of a sudden be too small? The result of my analysis is that several members of struct input_dev are too large, such as its member keybit. thanks, edward.
