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

Lee, Chun-Yi
2024-05-14T05:42:22Z

From: Chun-Yi Lee <jlee@suse.com>

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

But 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.

This patch adds dev_hold() to those functions and also uses dev_put()
when the skb_clone() returns NULL.

v2:
- Base on submitting-patches.rst document to improve patch description.
- Used curly brackets in the if-else blocks.

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>
---
drivers/block/aoe/aoecmd.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index cc9077b588d7..d1f4ddc57645 100644
--- 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;
}
--
2.35.3