From: Chun-Yi Lee <jlee@xxxxxxxx> This patch is against CVE-2023-6270. The description of cve is: A flaw was found in the ATA over Ethernet (AoE) driver in the Linux kernel. The aoecmd_cfg_pkts() function improperly updates the refcnt on `struct net_device`, and a use-after-free can be triggered by racing between the free on the struct and the access through the `skbtxq` global queue. This could lead to a denial of service condition or potential code execution. In aoecmd_cfg_pkts(), it always calls dev_put(ifp) when skb initial code is finished. But the net_device ifp will still be used in later tx()->dev_queue_xmit() in kthread. Which means that the dev_put(ifp) should NOT be called in the success path of skb initial code in aoecmd_cfg_pkts(). Otherwise tx() may run into use-after-free because the net_device is freed. This patch removed the dev_put(ifp) in the success path in aoecmd_cfg_pkts(), and added dev_put() after skb xmit in tx(). Link: https://nvd.nist.gov/vuln/detail/CVE-2023-6270 Fixes: 7562f876cd93 ("[NET]: Rework dev_base via list_head (v3)") Signed-off-by: Chun-Yi Lee <jlee@xxxxxxxx> --- drivers/block/aoe/aoecmd.c | 12 ++++++------ drivers/block/aoe/aoenet.c | 1 + 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c index d7317425be51..cc9077b588d7 100644 --- a/drivers/block/aoe/aoecmd.c +++ b/drivers/block/aoe/aoecmd.c @@ -419,13 +419,16 @@ aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff_head *qu rcu_read_lock(); for_each_netdev_rcu(&init_net, ifp) { dev_hold(ifp); - if (!is_aoe_netif(ifp)) - goto cont; + if (!is_aoe_netif(ifp)) { + dev_put(ifp); + continue; + } skb = new_skb(sizeof *h + sizeof *ch); if (skb == NULL) { printk(KERN_INFO "aoe: skb alloc failure\n"); - goto cont; + dev_put(ifp); + continue; } skb_put(skb, sizeof *h + sizeof *ch); skb->dev = ifp; @@ -440,9 +443,6 @@ aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff_head *qu h->major = cpu_to_be16(aoemajor); h->minor = aoeminor; h->cmd = AOECMD_CFG; - -cont: - dev_put(ifp); } rcu_read_unlock(); } diff --git a/drivers/block/aoe/aoenet.c b/drivers/block/aoe/aoenet.c index c51ea95bc2ce..923a134fd766 100644 --- a/drivers/block/aoe/aoenet.c +++ b/drivers/block/aoe/aoenet.c @@ -63,6 +63,7 @@ tx(int id) __must_hold(&txlock) pr_warn("aoe: packet could not be sent on %s. %s\n", ifp ? ifp->name : "netif", "consider increasing tx_queue_len"); + dev_put(ifp); spin_lock_irq(&txlock); } return 0; -- 2.35.3
