| Message ID | 20230723074110.3705047-1-linma@zju.edu.cn (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v1] xfrm: add forgotten nla_policy for XFRMA_MTIMER_THRESH | expand |
On Sun, Jul 23, 2023 at 03:41:10PM +0800, Lin Ma wrote: > The previous commit 4e484b3e969b ("xfrm: rate limit SA mapping change > message to user space") added one additional attribute named > XFRMA_MTIMER_THRESH and described its type at compat_policy > (net/xfrm/xfrm_compat.c). > > However, the author forgot to also describe the nla_policy at > xfrma_policy (net/xfrm/xfrm_user.c). Hence, this suppose NLA_U32 (4 > bytes) value can be faked as empty (0 bytes) by a malicious user, which > leads to 4 bytes overflow read and heap information leak when parsing > nlattrs. > > To exploit this, one malicious user can spray the SLUB objects and then > leverage this 4 bytes OOB read to leak the heap data into > x->mapping_maxage (see xfrm_update_ae_params(...)), and leak it to > userspace via copy_to_user_state_extra(...). > > The above bug is assigned CVE-2023-3773. To fix it, this commit just > completes the nla_policy description for XFRMA_MTIMER_THRESH, which > enforces the length check and avoids such OOB read. > > Fixes: 4e484b3e969b ("xfrm: rate limit SA mapping change message to user space") > Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Simon Horman <simon.horman@corigine.com>
On Sun, Jul 23, 2023 at 03:41:10PM +0800, Lin Ma wrote: > The previous commit 4e484b3e969b ("xfrm: rate limit SA mapping change > message to user space") added one additional attribute named > XFRMA_MTIMER_THRESH and described its type at compat_policy > (net/xfrm/xfrm_compat.c). > > However, the author forgot to also describe the nla_policy at > xfrma_policy (net/xfrm/xfrm_user.c). Hence, this suppose NLA_U32 (4 > bytes) value can be faked as empty (0 bytes) by a malicious user, which > leads to 4 bytes overflow read and heap information leak when parsing > nlattrs. > > To exploit this, one malicious user can spray the SLUB objects and then > leverage this 4 bytes OOB read to leak the heap data into > x->mapping_maxage (see xfrm_update_ae_params(...)), and leak it to > userspace via copy_to_user_state_extra(...). > > The above bug is assigned CVE-2023-3773. This CVE is a joke, you need to be root to execute this attack. Anyway change is ok. Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Hello Leon, > > This CVE is a joke, you need to be root to execute this attack. > Not really, this call routine only checks if (!netlink_net_capable(skb, CAP_NET_ADMIN)) return -EPERM; and any users in most vendor kernel can create a network namespace to get such privilege and trigger this bug. > Anyway change is ok. > Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Regards Lin
On Wed, Jul 26, 2023 at 09:32:43PM +0800, Lin Ma wrote: > Hello Leon, > > > > > This CVE is a joke, you need to be root to execute this attack. > > > > Not really, this call routine only checks > > if (!netlink_net_capable(skb, CAP_NET_ADMIN)) > return -EPERM; > > and any users in most vendor kernel can create a network namespace to > get such privilege and trigger this bug. ok, fair enough. > > > Anyway change is ok. > > Reviewed-by: Leon Romanovsky <leonro@nvidia.com> > > Regards > Lin
On Sun, Jul 23, 2023 at 03:41:10PM +0800, Lin Ma wrote: > The previous commit 4e484b3e969b ("xfrm: rate limit SA mapping change > message to user space") added one additional attribute named > XFRMA_MTIMER_THRESH and described its type at compat_policy > (net/xfrm/xfrm_compat.c). > > However, the author forgot to also describe the nla_policy at > xfrma_policy (net/xfrm/xfrm_user.c). Hence, this suppose NLA_U32 (4 > bytes) value can be faked as empty (0 bytes) by a malicious user, which > leads to 4 bytes overflow read and heap information leak when parsing > nlattrs. > > To exploit this, one malicious user can spray the SLUB objects and then > leverage this 4 bytes OOB read to leak the heap data into > x->mapping_maxage (see xfrm_update_ae_params(...)), and leak it to > userspace via copy_to_user_state_extra(...). > > The above bug is assigned CVE-2023-3773. To fix it, this commit just > completes the nla_policy description for XFRMA_MTIMER_THRESH, which > enforces the length check and avoids such OOB read. > > Fixes: 4e484b3e969b ("xfrm: rate limit SA mapping change message to user space") > Signed-off-by: Lin Ma <linma@zju.edu.cn> Also applied, thanks Lin!
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index c34a2a06ca94..ab0e73c1e352 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -3035,6 +3035,7 @@ const struct nla_policy xfrma_policy[XFRMA_MAX+1] = { [XFRMA_SET_MARK] = { .type = NLA_U32 }, [XFRMA_SET_MARK_MASK] = { .type = NLA_U32 }, [XFRMA_IF_ID] = { .type = NLA_U32 }, + [XFRMA_MTIMER_THRESH] = { .type = NLA_U32 }, }; EXPORT_SYMBOL_GPL(xfrma_policy);
The previous commit 4e484b3e969b ("xfrm: rate limit SA mapping change message to user space") added one additional attribute named XFRMA_MTIMER_THRESH and described its type at compat_policy (net/xfrm/xfrm_compat.c). However, the author forgot to also describe the nla_policy at xfrma_policy (net/xfrm/xfrm_user.c). Hence, this suppose NLA_U32 (4 bytes) value can be faked as empty (0 bytes) by a malicious user, which leads to 4 bytes overflow read and heap information leak when parsing nlattrs. To exploit this, one malicious user can spray the SLUB objects and then leverage this 4 bytes OOB read to leak the heap data into x->mapping_maxage (see xfrm_update_ae_params(...)), and leak it to userspace via copy_to_user_state_extra(...). The above bug is assigned CVE-2023-3773. To fix it, this commit just completes the nla_policy description for XFRMA_MTIMER_THRESH, which enforces the length check and avoids such OOB read. Fixes: 4e484b3e969b ("xfrm: rate limit SA mapping change message to user space") Signed-off-by: Lin Ma <linma@zju.edu.cn> --- net/xfrm/xfrm_user.c | 1 + 1 file changed, 1 insertion(+)