* [PATCH v2] libfc: sanity check cpu number extracted from xid
[not found] ` <20160630070925.ptbgkeq57txs55gf-3LAbnSA0sDC4fIQPS+WK3rNAH6kLmebB@public.gmane.org>
@ 2016-06-30 15:32 ` Chris Leech
[not found] ` <1467300756-7949-1-git-send-email-cleech-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-07-14 1:50 ` Martin K. Petersen
0 siblings, 2 replies; 4+ messages in thread
From: Chris Leech @ 2016-06-30 15:32 UTC (permalink / raw)
To: Johannes Thumshirn
Cc: fcoe-devel-s9riP+hp16TNLxjTenLetw, linux-scsi-u79uwXL29TY76Z2rM5mHXA
In the receive path libfc extracts a cpu number from the ox_id in the
fiber channel header and uses that to do a per_cpu_ptr conversion.
If, for some reason, a frame is received with an invalid ox_id,
per_cpu_ptr will return an invalid pointer and the libfc receive path
will panic the system trying to use it.
I'm currently looking at such a case, and I don't yet know why a
cpu number > nr_cpu_ids is appearing in an exchange id. But adding a
sanity check in libfc prevents a system panic, and seems like good idea
when dealing with frames coming in from the network.
Signed-off-by: Chris Leech <cleech-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
drivers/scsi/libfc/fc_exch.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 30f9ef0..e72673b 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -908,9 +908,17 @@ static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
{
struct fc_exch_pool *pool;
struct fc_exch *ep = NULL;
+ u16 cpu = xid & fc_cpu_mask;
+
+ if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
+ printk_ratelimited(KERN_ERR
+ "libfc: lookup request for XID = %d, "
+ "indicates invalid CPU %d\n", xid, cpu);
+ return NULL;
+ }
if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
- pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
+ pool = per_cpu_ptr(mp->pool, cpu);
spin_lock_bh(&pool->lock);
ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
if (ep) {
--
2.5.5
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] libfc: sanity check cpu number extracted from xid
[not found] ` <1467300756-7949-1-git-send-email-cleech-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
@ 2016-07-01 8:09 ` Johannes Thumshirn
2016-07-14 1:51 ` Martin K. Petersen
0 siblings, 1 reply; 4+ messages in thread
From: Johannes Thumshirn @ 2016-07-01 8:09 UTC (permalink / raw)
To: Chris Leech, Martin K . Petersen
Cc: fcoe-devel-s9riP+hp16TNLxjTenLetw, Johannes Thumshirn,
linux-scsi-u79uwXL29TY76Z2rM5mHXA
On Thu, Jun 30, 2016 at 08:32:36AM -0700, Chris Leech wrote:
> In the receive path libfc extracts a cpu number from the ox_id in the
> fiber channel header and uses that to do a per_cpu_ptr conversion.
> If, for some reason, a frame is received with an invalid ox_id,
> per_cpu_ptr will return an invalid pointer and the libfc receive path
> will panic the system trying to use it.
>
> I'm currently looking at such a case, and I don't yet know why a
> cpu number > nr_cpu_ids is appearing in an exchange id. But adding a
> sanity check in libfc prevents a system panic, and seems like good idea
> when dealing with frames coming in from the network.
>
> Signed-off-by: Chris Leech <cleech-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> ---
> drivers/scsi/libfc/fc_exch.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
> index 30f9ef0..e72673b 100644
> --- a/drivers/scsi/libfc/fc_exch.c
> +++ b/drivers/scsi/libfc/fc_exch.c
> @@ -908,9 +908,17 @@ static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
> {
> struct fc_exch_pool *pool;
> struct fc_exch *ep = NULL;
> + u16 cpu = xid & fc_cpu_mask;
> +
> + if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
> + printk_ratelimited(KERN_ERR
> + "libfc: lookup request for XID = %d, "
> + "indicates invalid CPU %d\n", xid, cpu);
> + return NULL;
> + }
>
> if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
> - pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
> + pool = per_cpu_ptr(mp->pool, cpu);
> spin_lock_bh(&pool->lock);
> ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
> if (ep) {
Acked-by: Johannes Thumshirn <jth-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
@Martin, do you queue the libfc patches as well?
--
Johannes Thumshirn Storage
jthumshirn-l3A5Bk7waGM@public.gmane.org +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] libfc: sanity check cpu number extracted from xid
2016-06-30 15:32 ` [PATCH v2] libfc: sanity check cpu number extracted from xid Chris Leech
[not found] ` <1467300756-7949-1-git-send-email-cleech-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
@ 2016-07-14 1:50 ` Martin K. Petersen
1 sibling, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2016-07-14 1:50 UTC (permalink / raw)
To: Chris Leech; +Cc: Johannes Thumshirn, fcoe-devel, linux-scsi, Vasu Dev
>>>>> "Chris" == Chris Leech <cleech@redhat.com> writes:
Chris> In the receive path libfc extracts a cpu number from the ox_id in
Chris> the fiber channel header and uses that to do a per_cpu_ptr
Chris> conversion. If, for some reason, a frame is received with an
Chris> invalid ox_id, per_cpu_ptr will return an invalid pointer and the
Chris> libfc receive path will panic the system trying to use it.
Applied to 4.8/scsi-queue.
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] libfc: sanity check cpu number extracted from xid
2016-07-01 8:09 ` Johannes Thumshirn
@ 2016-07-14 1:51 ` Martin K. Petersen
0 siblings, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2016-07-14 1:51 UTC (permalink / raw)
To: Johannes Thumshirn
Cc: Chris Leech, Martin K . Petersen, Johannes Thumshirn, fcoe-devel,
linux-scsi, Vasu Dev
>>>>> "Johannes" == Johannes Thumshirn <jthumshirn@suse.de> writes:
Johannes> @Martin, do you queue the libfc patches as well?
Sure.
(Sorry about the delay, been on vacation).
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-07-14 1:51 UTC | newest]
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[not found] ` <20160630070925.ptbgkeq57txs55gf-3LAbnSA0sDC4fIQPS+WK3rNAH6kLmebB@public.gmane.org>
2016-06-30 15:32 ` [PATCH v2] libfc: sanity check cpu number extracted from xid Chris Leech
[not found] ` <1467300756-7949-1-git-send-email-cleech-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-07-01 8:09 ` Johannes Thumshirn
2016-07-14 1:51 ` Martin K. Petersen
2016-07-14 1:50 ` Martin K. Petersen
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