* [PATCH] resource: Fix integer overflow at reallocation
@ 2018-04-02 7:16 Takashi Iwai
2018-04-02 19:09 ` Ram Pai
2018-04-05 1:34 ` Sasha Levin
0 siblings, 2 replies; 6+ messages in thread
From: Takashi Iwai @ 2018-04-02 7:16 UTC (permalink / raw)
To: Bjorn Helgaas; +Cc: linux-kernel, Michael Henders, Ram Pai
We've got a bug report indicating a kernel panic at booting on an
x86-32 system, and it turned out to be the invalid resource assigned
after reallocation. __find_resource() first aligns the resource start
address and resets the end address with start+size-1 accordingly, then
checks whether it's contained. Here the end address may overflow the
integer, although resource_contains() still returns true because the
function validates only start and end address. So this ends up with
returning an invalid resource (start > end).
There was already an attempt to cover such a problem in the commit
47ea91b4052d ("Resource: fix wrong resource window calculation"), but
this case is an overseen one.
This patch adds the validity check of the newly calculated resource
for avoiding the integer overflow problem.
Bugzilla: http://bugzilla.opensuse.org/show_bug.cgi?id=1086739
Fixes: 23c570a67448 ("resource: ability to resize an allocated resource")
Reported-and-tested-by: Michael Henders <hendersm@shaw.ca>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
Bjorn, I send this to you since the bug hits during PCI init, although
the culprit is in generic resource management.
kernel/resource.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/resource.c b/kernel/resource.c
index e270b5048988..2af6c03858b9 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -651,7 +651,8 @@ static int __find_resource(struct resource *root, struct resource *old,
alloc.start = constraint->alignf(constraint->alignf_data, &avail,
size, constraint->align);
alloc.end = alloc.start + size - 1;
- if (resource_contains(&avail, &alloc)) {
+ if (alloc.start <= alloc.end &&
+ resource_contains(&avail, &alloc)) {
new->start = alloc.start;
new->end = alloc.end;
return 0;
--
2.16.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] resource: Fix integer overflow at reallocation 2018-04-02 7:16 [PATCH] resource: Fix integer overflow at reallocation Takashi Iwai @ 2018-04-02 19:09 ` Ram Pai 2018-04-02 20:35 ` Takashi Iwai 2018-04-05 1:34 ` Sasha Levin 1 sibling, 1 reply; 6+ messages in thread From: Ram Pai @ 2018-04-02 19:09 UTC (permalink / raw) To: Takashi Iwai; +Cc: Bjorn Helgaas, linux-kernel, Michael Henders On Mon, Apr 02, 2018 at 09:16:16AM +0200, Takashi Iwai wrote: > We've got a bug report indicating a kernel panic at booting on an > x86-32 system, and it turned out to be the invalid resource assigned > after reallocation. __find_resource() first aligns the resource start > address and resets the end address with start+size-1 accordingly, then > checks whether it's contained. Here the end address may overflow the > integer, although resource_contains() still returns true because the > function validates only start and end address. So this ends up with > returning an invalid resource (start > end). > > There was already an attempt to cover such a problem in the commit > 47ea91b4052d ("Resource: fix wrong resource window calculation"), but > this case is an overseen one. > > This patch adds the validity check of the newly calculated resource > for avoiding the integer overflow problem. Should we move this check "alloc.start <= alloc.end" into resource_contains()? Doing so will catch all uses of such erroneous (overflowing) resources. RP > > Bugzilla: https://urldefense.proofpoint.com/v2/url?u=http-3A__bugzilla.opensuse.org_show-5Fbug.cgi-3Fid-3D1086739&d=DwIBAg&c=jf_iaSHvJObTbx-siA1ZOg&r=m-UrKChQVkZtnPpjbF6YY99NbT8FBByQ-E-ygV8luxw&m=FoiwlR-LTJ9_EBQsLYSCqXuWrGhU1lXycdvhbaK7wOk&s=clxOtFUIAMlPNwQJZTaKnmIta9pMtJ8XprmwVd-ylvo&e= > Fixes: 23c570a67448 ("resource: ability to resize an allocated resource") > Reported-and-tested-by: Michael Henders <hendersm@shaw.ca> > Cc: <stable@vger.kernel.org> > Signed-off-by: Takashi Iwai <tiwai@suse.de> > --- > > Bjorn, I send this to you since the bug hits during PCI init, although > the culprit is in generic resource management. > > kernel/resource.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/resource.c b/kernel/resource.c > index e270b5048988..2af6c03858b9 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -651,7 +651,8 @@ static int __find_resource(struct resource *root, struct resource *old, > alloc.start = constraint->alignf(constraint->alignf_data, &avail, > size, constraint->align); > alloc.end = alloc.start + size - 1; > - if (resource_contains(&avail, &alloc)) { > + if (alloc.start <= alloc.end && > + resource_contains(&avail, &alloc)) { > new->start = alloc.start; > new->end = alloc.end; > return 0; > -- > 2.16.2 -- Ram Pai ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] resource: Fix integer overflow at reallocation 2018-04-02 19:09 ` Ram Pai @ 2018-04-02 20:35 ` Takashi Iwai 2018-04-05 14:40 ` Takashi Iwai 0 siblings, 1 reply; 6+ messages in thread From: Takashi Iwai @ 2018-04-02 20:35 UTC (permalink / raw) To: Ram Pai; +Cc: Bjorn Helgaas, linux-kernel, Michael Henders On Mon, 02 Apr 2018 21:09:03 +0200, Ram Pai wrote: > > On Mon, Apr 02, 2018 at 09:16:16AM +0200, Takashi Iwai wrote: > > We've got a bug report indicating a kernel panic at booting on an > > x86-32 system, and it turned out to be the invalid resource assigned > > after reallocation. __find_resource() first aligns the resource start > > address and resets the end address with start+size-1 accordingly, then > > checks whether it's contained. Here the end address may overflow the > > integer, although resource_contains() still returns true because the > > function validates only start and end address. So this ends up with > > returning an invalid resource (start > end). > > > > There was already an attempt to cover such a problem in the commit > > 47ea91b4052d ("Resource: fix wrong resource window calculation"), but > > this case is an overseen one. > > > > This patch adds the validity check of the newly calculated resource > > for avoiding the integer overflow problem. > > Should we move this check "alloc.start <= alloc.end" into resource_contains()? > Doing so will catch all uses of such erroneous (overflowing) resources. I thought of it, too. OTOH, it's rather a validity check and doesn't belong to resource_contains() semantics. If the function returns false, you don't know whether it's an invalid resource or it's really not contained. We may return an error code, but I'm not sure whether such an API change is needed. Maybe not. thanks, Takashi > > RP > > > > > Bugzilla: https://urldefense.proofpoint.com/v2/url?u=http-3A__bugzilla.opensuse.org_show-5Fbug.cgi-3Fid-3D1086739&d=DwIBAg&c=jf_iaSHvJObTbx-siA1ZOg&r=m-UrKChQVkZtnPpjbF6YY99NbT8FBByQ-E-ygV8luxw&m=FoiwlR-LTJ9_EBQsLYSCqXuWrGhU1lXycdvhbaK7wOk&s=clxOtFUIAMlPNwQJZTaKnmIta9pMtJ8XprmwVd-ylvo&e= > > Fixes: 23c570a67448 ("resource: ability to resize an allocated resource") > > Reported-and-tested-by: Michael Henders <hendersm@shaw.ca> > > Cc: <stable@vger.kernel.org> > > Signed-off-by: Takashi Iwai <tiwai@suse.de> > > --- > > > > Bjorn, I send this to you since the bug hits during PCI init, although > > the culprit is in generic resource management. > > > > kernel/resource.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/resource.c b/kernel/resource.c > > index e270b5048988..2af6c03858b9 100644 > > --- a/kernel/resource.c > > +++ b/kernel/resource.c > > @@ -651,7 +651,8 @@ static int __find_resource(struct resource *root, struct resource *old, > > alloc.start = constraint->alignf(constraint->alignf_data, &avail, > > size, constraint->align); > > alloc.end = alloc.start + size - 1; > > - if (resource_contains(&avail, &alloc)) { > > + if (alloc.start <= alloc.end && > > + resource_contains(&avail, &alloc)) { > > new->start = alloc.start; > > new->end = alloc.end; > > return 0; > > -- > > 2.16.2 > > -- > Ram Pai > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] resource: Fix integer overflow at reallocation 2018-04-02 20:35 ` Takashi Iwai @ 2018-04-05 14:40 ` Takashi Iwai 2018-04-06 0:23 ` Ram Pai 0 siblings, 1 reply; 6+ messages in thread From: Takashi Iwai @ 2018-04-05 14:40 UTC (permalink / raw) To: Ram Pai; +Cc: Bjorn Helgaas, linux-kernel, Michael Henders On Mon, 02 Apr 2018 22:35:04 +0200, Takashi Iwai wrote: > > On Mon, 02 Apr 2018 21:09:03 +0200, > Ram Pai wrote: > > > > On Mon, Apr 02, 2018 at 09:16:16AM +0200, Takashi Iwai wrote: > > > We've got a bug report indicating a kernel panic at booting on an > > > x86-32 system, and it turned out to be the invalid resource assigned > > > after reallocation. __find_resource() first aligns the resource start > > > address and resets the end address with start+size-1 accordingly, then > > > checks whether it's contained. Here the end address may overflow the > > > integer, although resource_contains() still returns true because the > > > function validates only start and end address. So this ends up with > > > returning an invalid resource (start > end). > > > > > > There was already an attempt to cover such a problem in the commit > > > 47ea91b4052d ("Resource: fix wrong resource window calculation"), but > > > this case is an overseen one. > > > > > > This patch adds the validity check of the newly calculated resource > > > for avoiding the integer overflow problem. > > > > Should we move this check "alloc.start <= alloc.end" into resource_contains()? > > Doing so will catch all uses of such erroneous (overflowing) resources. > > I thought of it, too. OTOH, it's rather a validity check and doesn't > belong to resource_contains() semantics. If the function returns > false, you don't know whether it's an invalid resource or it's really > not contained. > > We may return an error code, but I'm not sure whether such an API > change is needed. Maybe not. FWIW, below is the revised one to move the check into resource_contains(). My concern is, however, that the resource validity check isn't a job of resource_contains(). OTOH, this may avoid other similar cases, so it might be worth. In anyway, if there is no objection, and anyone else doesn't want to take, I'll forward this to Andrew as a poor orphan kid. thanks, Takashi -- 8< -- From: Takashi Iwai <tiwai@suse.de> Subject: [PATCH v2] resource: Fix integer overflow at reallocation We've got a bug report indicating a kernel panic at booting on an x86-32 system, and it turned out to be the invalid resource assigned after reallocation. __find_resource() first aligns the resource start address and resets the end address with start+size-1 accordingly, then checks whether it's contained. Here the end address may overflow the integer, although resource_contains() still returns true because the function validates only start and end address. So this ends up with returning an invalid resource (start > end). There was already an attempt to cover such a problem in the commit 47ea91b4052d ("Resource: fix wrong resource window calculation"), but this case is an overseen one. This patch adds the validity check in resource_contains() to see whether the given resource has a valid range for avoiding the integer overflow problem. Bugzilla: http://bugzilla.opensuse.org/show_bug.cgi?id=1086739 Fixes: 23c570a67448 ("resource: ability to resize an allocated resource") Reported-and-tested-by: Michael Henders <hendersm@shaw.ca> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> --- include/linux/ioport.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index da0ebaec25f0..466d7be046eb 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -212,6 +212,9 @@ static inline bool resource_contains(struct resource *r1, struct resource *r2) return false; if (r1->flags & IORESOURCE_UNSET || r2->flags & IORESOURCE_UNSET) return false; + /* sanity check whether it's a valid resource range */ + if (r2->end < r2->start) + return false; return r1->start <= r2->start && r1->end >= r2->end; } -- 2.16.3 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] resource: Fix integer overflow at reallocation 2018-04-05 14:40 ` Takashi Iwai @ 2018-04-06 0:23 ` Ram Pai 0 siblings, 0 replies; 6+ messages in thread From: Ram Pai @ 2018-04-06 0:23 UTC (permalink / raw) To: Takashi Iwai; +Cc: Bjorn Helgaas, linux-kernel, Michael Henders On Thu, Apr 05, 2018 at 04:40:15PM +0200, Takashi Iwai wrote: > On Mon, 02 Apr 2018 22:35:04 +0200, > Takashi Iwai wrote: > > > > On Mon, 02 Apr 2018 21:09:03 +0200, > > Ram Pai wrote: > > > > > > On Mon, Apr 02, 2018 at 09:16:16AM +0200, Takashi Iwai wrote: > > > > We've got a bug report indicating a kernel panic at booting on an > > > > x86-32 system, and it turned out to be the invalid resource assigned > > > > after reallocation. __find_resource() first aligns the resource start > > > > address and resets the end address with start+size-1 accordingly, then > > > > checks whether it's contained. Here the end address may overflow the > > > > integer, although resource_contains() still returns true because the > > > > function validates only start and end address. So this ends up with > > > > returning an invalid resource (start > end). > > > > > > > > There was already an attempt to cover such a problem in the commit > > > > 47ea91b4052d ("Resource: fix wrong resource window calculation"), but > > > > this case is an overseen one. > > > > > > > > This patch adds the validity check of the newly calculated resource > > > > for avoiding the integer overflow problem. > > > > > > Should we move this check "alloc.start <= alloc.end" into resource_contains()? > > > Doing so will catch all uses of such erroneous (overflowing) resources. > > > > I thought of it, too. OTOH, it's rather a validity check and doesn't > > belong to resource_contains() semantics. If the function returns > > false, you don't know whether it's an invalid resource or it's really > > not contained. > > > > We may return an error code, but I'm not sure whether such an API > > change is needed. Maybe not. > > FWIW, below is the revised one to move the check into > resource_contains(). > > My concern is, however, that the resource validity check isn't a job > of resource_contains(). OTOH, this may avoid other similar cases, so > it might be worth. > > In anyway, if there is no objection, and anyone else doesn't want to > take, I'll forward this to Andrew as a poor orphan kid. I will stand by you as a poor-orphan-buddy. :-) Reviewed-by: Ram Pai <linuxram@us.ibm.com> RP > > > thanks, > > Takashi > > -- 8< -- > From: Takashi Iwai <tiwai@suse.de> > Subject: [PATCH v2] resource: Fix integer overflow at reallocation > > We've got a bug report indicating a kernel panic at booting on an > x86-32 system, and it turned out to be the invalid resource assigned > after reallocation. __find_resource() first aligns the resource start > address and resets the end address with start+size-1 accordingly, then > checks whether it's contained. Here the end address may overflow the > integer, although resource_contains() still returns true because the > function validates only start and end address. So this ends up with > returning an invalid resource (start > end). > > There was already an attempt to cover such a problem in the commit > 47ea91b4052d ("Resource: fix wrong resource window calculation"), but > this case is an overseen one. > > This patch adds the validity check in resource_contains() to see > whether the given resource has a valid range for avoiding the integer > overflow problem. > > Bugzilla: https://urldefense.proofpoint.com/v2/url?u=http-3A__bugzilla.opensuse.org_show-5Fbug.cgi-3Fid-3D1086739&d=DwIBAg&c=jf_iaSHvJObTbx-siA1ZOg&r=m-UrKChQVkZtnPpjbF6YY99NbT8FBByQ-E-ygV8luxw&m=NNkNAWFZc1XRu3rkv7Y2sepSCe8re2cvNZuCJt5dWFE&s=7i3g3ZVYsUceGVK_ZKkCJIABp4l0RD59NelK3GoD8mI&e= > Fixes: 23c570a67448 ("resource: ability to resize an allocated resource") > Reported-and-tested-by: Michael Henders <hendersm@shaw.ca> > Cc: <stable@vger.kernel.org> > Signed-off-by: Takashi Iwai <tiwai@suse.de> > --- > include/linux/ioport.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/include/linux/ioport.h b/include/linux/ioport.h > index da0ebaec25f0..466d7be046eb 100644 > --- a/include/linux/ioport.h > +++ b/include/linux/ioport.h > @@ -212,6 +212,9 @@ static inline bool resource_contains(struct resource *r1, struct resource *r2) > return false; > if (r1->flags & IORESOURCE_UNSET || r2->flags & IORESOURCE_UNSET) > return false; > + /* sanity check whether it's a valid resource range */ > + if (r2->end < r2->start) > + return false; > return r1->start <= r2->start && r1->end >= r2->end; > } > > -- > 2.16.3 -- Ram Pai ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] resource: Fix integer overflow at reallocation 2018-04-02 7:16 [PATCH] resource: Fix integer overflow at reallocation Takashi Iwai 2018-04-02 19:09 ` Ram Pai @ 2018-04-05 1:34 ` Sasha Levin 1 sibling, 0 replies; 6+ messages in thread From: Sasha Levin @ 2018-04-05 1:34 UTC (permalink / raw) To: Sasha Levin, Takashi Iwai, Bjorn Helgaas Cc: linux-kernel, Michael Henders, stable, stable Hi Takashi Iwai. [This is an automated email] This commit has been processed because it contains a "Fixes:" tag. fixing commit: 23c570a67448 resource: ability to resize an allocated resource. The bot has also determined it's probably a bug fixing patch. (score: 99.2157) The bot has tested the following trees: v4.15.15, v4.14.32, v4.9.92, v4.4.126, v4.15.15: Build OK! v4.14.32: Build OK! v4.9.92: Build OK! v4.4.126: Build OK! -- Thanks. Sasha ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-04-06 0:23 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-04-02 7:16 [PATCH] resource: Fix integer overflow at reallocation Takashi Iwai 2018-04-02 19:09 ` Ram Pai 2018-04-02 20:35 ` Takashi Iwai 2018-04-05 14:40 ` Takashi Iwai 2018-04-06 0:23 ` Ram Pai 2018-04-05 1:34 ` Sasha Levin
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.