Re: [PATCH] ieee802154: hwsim: fix possible null-pointer dereference in mac802154_hwsim.c

From: Stefan Schmidt
Date: Wed Aug 11 2021 - 16:08:47 EST


Hello.

On 11.08.21 04:36, Tuo Li wrote:
In hwsim_new_edge_nl() and hwsim_set_edge_lqi(), if only one of the two
info->attrs is NULL, the functions will not return.
if (!info->attrs[MAC802154_HWSIM_ATTR_RADIO_ID] &&
!info->attrs[MAC802154_HWSIM_ATTR_RADIO_EDGE])
return -EINVAL;

However, both of them may be dereferenced in the function
nla_parse_nested_deprecated(), causing a null-pointer dereference.
To fix this possible null-pointer dereference, the function returns
-EINVAL if any info_attr is NULL.

Similarly, in hwsim_set_edge_lqi(), if only one of the two edge_attrs is
NULL, both nla_get_u32() and nla_get_u8() will be called, causing a
null-pointer dereference.
Also, to fix this possible null-pointer dereference, the function returns
-EINVAL if any edge_attr is NULL.

Fixes: f25da51fdc38 ("ieee802154: hwsim: add replacement for fakelb")
Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
Signed-off-by: Tuo Li <islituo@xxxxxxxxx>

Thanks for your patch. This has already been fixed with patches in the wpan tree.
https://git.kernel.org/pub/scm/linux/kernel/git/sschmidt/wpan.git/

I just sent a pull request including them to get pulled into net.

regards
Stefan Schmidt