| Message ID | 20240912102935.31442-1-jlee@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] aoe: fix the potential use-after-free problem in more places | expand |
> 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. We've tested your patch on our servers and ran into an issue. With heavy I/O load the aoe device had stale I/Os (e.g. rsync waiting indefinetly on one core) that can be "fixed" by running aoe-revalidate on that device. Additionally when trying to shut down the system we see the message: unregister_netdevice: waiting for XXX to become free. Usage Count = XXXXX on aoe devices with a usage count somewhere in the millions. This has been the same as without the patch, i assume the fix is still incomplete. Thanks for your work, Valentin
On Thu, Sep 12, 2024 at 06:29:35PM +0800, Chun-Yi Lee wrote: > 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. > > 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> > --- > Hi, This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him a patch that has triggered this response. He used to manually respond to these common problems, but in order to save his sanity (he kept writing the same thing over and over, yet to different people), I was created. Hopefully you will not take offence and will fix the problem in your patch and resubmit it so that it can be accepted into the Linux kernel tree. You are receiving this message because of the following common error(s) as indicated below: - You have marked a patch with a "Fixes:" tag for a commit that is in an older released kernel, yet you do not have a cc: stable line in the signed-off-by area at all, which means that the patch will not be applied to any older kernel releases. To properly fix this, please follow the documented rules in the Documentation/process/stable-kernel-rules.rst file for how to resolve this. If you wish to discuss this problem further, or you have questions about how to resolve this issue, please feel free to respond to this email and Greg will reply once he has dug out from the pending patches received from other developers. thanks, greg k-h's patch email bot
Hi Valentin, On Thu, Sep 12, 2024 at 12:58:46PM +0200, Valentin Kleibel wrote: > > 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. > > We've tested your patch on our servers and ran into an issue. > With heavy I/O load the aoe device had stale I/Os (e.g. rsync waiting > indefinetly on one core) that can be "fixed" by running aoe-revalidate on > that device. > > Additionally when trying to shut down the system we see the message: > unregister_netdevice: waiting for XXX to become free. Usage Count = XXXXX > on aoe devices with a usage count somewhere in the millions. > This has been the same as without the patch, i assume the fix is still > incomplete. > Thanks for your testing! I will look into it and reproduce issue again for improvement. Joey Lee
Hi Valentin, On Thu, Sep 12, 2024 at 12:58:46PM +0200, Valentin Kleibel wrote: > > 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. > > We've tested your patch on our servers and ran into an issue. > With heavy I/O load the aoe device had stale I/Os (e.g. rsync waiting > indefinetly on one core) that can be "fixed" by running aoe-revalidate on > that device. > > Additionally when trying to shut down the system we see the message: > unregister_netdevice: waiting for XXX to become free. Usage Count = XXXXX > on aoe devices with a usage count somewhere in the millions. > This has been the same as without the patch, i assume the fix is still > incomplete. > For the reference count debugging, I have sent a patch series here: [RFC PATCH 0/2] tracking the references of net_device in aoe https://lore.kernel.org/lkml/20241002040616.25193-1-jlee@suse.com/T/#t Base on my testing, the number of dev_hold(nd) and dev_put(nd) are balance in aoe after the this 'aoe: fix the potential use-after-free problem in more places' patch be applied on v6.11 kernel. I have tested add/modify/delete files in remote target by aoe. My testing is not a heavy I/O testing. But the result is balance. Could you please help to try the above debug patch series for looking at the refcnt value in aoe in your side? Thanks a lot! Joey Lee
Hi Joey, >> We've tested your patch on our servers and ran into an issue. >> With heavy I/O load the aoe device had stale I/Os (e.g. rsync waiting >> indefinetly on one core) that can be "fixed" by running aoe-revalidate on >> that device. [...]> For the reference count debugging, I have sent a patch series here: > > [RFC PATCH 0/2] tracking the references of net_device in aoe > https://lore.kernel.org/lkml/20241002040616.25193-1-jlee@suse.com/T/#t > > Base on my testing, the number of dev_hold(nd) and dev_put(nd) are balance > in aoe after the this 'aoe: fix the potential use-after-free problem in more places' > patch be applied on v6.11 kernel. I have tested add/modify/delete files in remote > target by aoe. My testing is not a heavy I/O testing. But the result is > balance. > > Could you please help to try the above debug patch series for looking at the > refcnt value in aoe in your side? Thanks for your work, i can confirm refcnt value is balanced and the issue is fixed now. However, the I/O waiting issue reported before is still there, and occurs more often now. This problem started with the first patch CVE-2023-6270 applied in commit f98364e92662. This only happens with heavy I/O on our "older" storage systems with spinning disks. Unfortunately we do not know how we could debug this, have you got any hints what we could do? Thanks, Valentin PS: sorry for the delay, I'm now back from a long vacation
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; }
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. 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> --- v2: - Improve patch description - Improved wording - Add oneline summary of the commit f98364e92662 - Used curly brackets in the if-else blocks. drivers/block/aoe/aoecmd.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)