aoe: fix the potential use-after-free problem in more places

For fixing CVE-2023-6270, f98364e92662 ("aoe: fix the potential
use-after-free problem in aoecmd_cfg_pkts") makes tx() calling dev_put()
instead of doing in aoecmd_cfg_pkts(). It avoids that the tx() runs
into use-after-free.

Then Nicolai Stange found more places in aoe have potential use-after-free
problem with tx(). e.g. revalidate(), aoecmd_ata_rw(), resend(), probe()
and aoecmd_cfg_rsp(). Those functions also use aoenet_xmit() to push
packet to tx queue. So they should also use dev_hold() to increase the
refcnt of skb->dev.

On the other hand, moving dev_put() to tx() causes that the refcnt of
skb->dev be reduced to a negative value, because corresponding
dev_hold() are not called in revalidate(), aoecmd_ata_rw(), resend(),
probe(), and aoecmd_cfg_rsp(). This patch fixed this issue.

Cc: stable@vger.kernel.org
Link: https://nvd.nist.gov/vuln/detail/CVE-2023-6270
Fixes: f98364e92662 ("aoe: fix the potential use-after-free problem in aoecmd_cfg_pkts")
Reported-by: Nicolai Stange <nstange@suse.com>
Signed-off-by: Chun-Yi Lee <jlee@suse.com>
Link: https://lore.kernel.org/stable/20240624064418.27043-1-jlee%40suse.com
Link: https://lore.kernel.org/r/20241002035458.24401-1-jlee@suse.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index cc9077b588d7e7af30401ab03c826a358b2a232c..d1f4ddc576451a8814a0a27c7101e56c99d3d32a 100644 (file)
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -361,6 +361,7 @@ ata_rw_frameinit(struct frame *f)
        }
 
        ah->cmdstat = ATA_CMD_PIO_READ | writebit | extbit;
+       dev_hold(t->ifp->nd);
        skb->dev = t->ifp->nd;
 }
 
@@ -401,6 +402,8 @@ aoecmd_ata_rw(struct aoedev *d)
                __skb_queue_head_init(&queue);
                __skb_queue_tail(&queue, skb);
                aoenet_xmit(&queue);
+       } else {
+               dev_put(f->t->ifp->nd);
        }
        return 1;
 }
@@ -483,10 +486,13 @@ resend(struct aoedev *d, struct frame *f)
        memcpy(h->dst, t->addr, sizeof h->dst);
        memcpy(h->src, t->ifp->nd->dev_addr, sizeof h->src);
 
+       dev_hold(t->ifp->nd);
        skb->dev = t->ifp->nd;
        skb = skb_clone(skb, GFP_ATOMIC);
-       if (skb == NULL)
+       if (skb == NULL) {
+               dev_put(t->ifp->nd);
                return;
+       }
        f->sent = ktime_get();
        __skb_queue_head_init(&queue);
        __skb_queue_tail(&queue, skb);
@@ -617,6 +623,8 @@ probe(struct aoetgt *t)
                __skb_queue_head_init(&queue);
                __skb_queue_tail(&queue, skb);
                aoenet_xmit(&queue);
+       } else {
+               dev_put(f->t->ifp->nd);
        }
 }
 
@@ -1395,6 +1403,7 @@ aoecmd_ata_id(struct aoedev *d)
        ah->cmdstat = ATA_CMD_ID_ATA;
        ah->lba3 = 0xa0;
 
+       dev_hold(t->ifp->nd);
        skb->dev = t->ifp->nd;
 
        d->rttavg = RTTAVG_INIT;
@@ -1404,6 +1413,8 @@ aoecmd_ata_id(struct aoedev *d)
        skb = skb_clone(skb, GFP_ATOMIC);
        if (skb)
                f->sent = ktime_get();
+       else
+               dev_put(t->ifp->nd);
 
        return skb;
 }