Messages in this thread Patch in this message | | | From | Lin Ma <> | Subject | [PATCH v1] xfrm: add forgotten nla_policy for XFRMA_MTIMER_THRESH | Date | Sun, 23 Jul 2023 15:41:10 +0800 |
| |
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(+)
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); -- 2.17.1
| |