Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: tun: zero the whole vnet header in tun_put_user() tun_put_user() declares an on-stack struct virtio_net_hdr_v1_hash_tunnel without zeroing it. For a non-tunnel skb, virtio_net_hdr_tnl_from_skb() only initializes the first 10 bytes (sizeof(struct virtio_net_hdr)), leaving bytes 10..23 (num_buffers and the hash/tunnel fields) as stack garbage. An unprivileged user can set the vnet header size to 24 with TUNSETVNETHDRSZ, so __tun_vnet_hdr_put() copies all 24 bytes of the partially-initialized struct to userspace, leaking 14 bytes of kernel stack on every read of a non-tunnel packet. Fix it the same way tun_get_user() already does by zeroing the whole header right after declaration.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 288f30435132d2f9e7a29ec9b9745a4f9dc7fd37 before 5fd1fa5a4254bfdd70571c77f5e3bcb4e43738d5; affected 288f30435132d2f9e7a29ec9b9745a4f9dc7fd37 before 585cb85e9a29185be05f326369573c2663cf4380; affected 288f30435132d2f9e7a29ec9b9745a4f9dc7fd37 before 7f2fcff15e99bb852f6967396ed12b38376e2c8d |
| Linux / Linux | affected 6.17; unaffected 0 before 6.17; unaffected 6.18.36 through 6.18.*; unaffected 7.0.13 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.