* Re: [PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls
2021-12-02 4:29 ` [PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls Andrew Morton
@ 2021-12-02 10:38 ` Jeremy Sowden
2021-12-02 15:34 ` Alexei Starovoitov
2021-12-02 11:49 ` Bixuan Cui
2021-12-03 19:37 ` Sean Christopherson
2 siblings, 1 reply; 6+ messages in thread
From: Jeremy Sowden @ 2021-12-02 10:38 UTC (permalink / raw)
To: Andrew Morton
Cc: Bixuan Cui, linux-mm, linux-kernel, torvalds, leon, w, keescook,
bpf, netdev, Alexei Starovoitov, Daniel Borkmann, Jakub Kicinski,
kvm, netfilter-devel
[-- Attachment #1: Type: text/plain, Size: 1967 bytes --]
On 2021-12-01, at 20:29:05 -0800, Andrew Morton wrote:
> On Thu, 2 Dec 2021 12:05:15 +0800 Bixuan Cui wrote:
> > 在 2021/12/2 上午11:26, Andrew Morton 写道:
> > >> Delete the WARN_ON() and return NULL directly for oversized
> > >> parameter in kvmalloc() calls.
> > >> Also add unlikely().
> > >>
> > >> Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls")
> > >> Signed-off-by: Bixuan Cui<cuibixuan@linux.alibaba.com>
> > >> ---
> > >> There are a lot of oversize warnings and patches about kvmalloc()
> > >> calls recently. Maybe these warnings are not very necessary.
> > >
> > > Or maybe they are. Please let's take a look at these warnings,
> > > one at a time. If a large number of them are bogus then sure,
> > > let's disable the runtime test. But perhaps it's the case that
> > > calling code has genuine issues and should be repaired.
> >
> > Such as：
>
> Thanks, that's helpful.
>
> Let's bring all these to the attention of the relevant developers.
>
> If the consensus is "the code's fine, the warning is bogus" then let's
> consider retiring the warning.
>
> If the consensus is otherwise then hopefully they will fix their stuff!
>
> > https://syzkaller.appspot.com/bug?id=24452f89446639c901ac07379ccc702808471e8e
>
> (cc bpf@vger.kernel.org)
>
> > https://syzkaller.appspot.com/bug?id=f7c5a86e747f9b7ce333e7295875cd4ede2c7a0d
>
> (cc netdev@vger.kernel.org, maintainers)
>
> > https://syzkaller.appspot.com/bug?id=8f306f3db150657a1f6bbe1927467084531602c7
>
> (cc kvm@vger.kernel.org)
>
> > https://syzkaller.appspot.com/bug?id=6f30adb592d476978777a1125d1f680edfc23e00
>
> (cc netfilter-devel@vger.kernel.org)
The netfilter bug has since been fixed:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?id=7bbc3d385bd813077acaf0e6fdb2a86a901f5382
> > https://syzkaller.appspot.com/bug?id=4c9ab8c7d0f8b551950db06559dc9cde4119ac83
>
> (bpf again).
J.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls
2021-12-02 10:38 ` Jeremy Sowden
@ 2021-12-02 15:34 ` Alexei Starovoitov
2021-12-02 21:16 ` Jeremy Sowden
0 siblings, 1 reply; 6+ messages in thread
From: Alexei Starovoitov @ 2021-12-02 15:34 UTC (permalink / raw)
To: Jeremy Sowden
Cc: Andrew Morton, Bixuan Cui, linux-mm, LKML, Linus Torvalds,
Leon Romanovsky, Willy Tarreau, Kees Cook, bpf,
Network Development, Alexei Starovoitov, Daniel Borkmann,
Jakub Kicinski, kvm, netfilter-devel
On Thu, Dec 2, 2021 at 2:38 AM Jeremy Sowden <jeremy@azazel.net> wrote:
>
> On 2021-12-01, at 20:29:05 -0800, Andrew Morton wrote:
> > On Thu, 2 Dec 2021 12:05:15 +0800 Bixuan Cui wrote:
> > > 在 2021/12/2 上午11:26, Andrew Morton 写道:
> > > >> Delete the WARN_ON() and return NULL directly for oversized
> > > >> parameter in kvmalloc() calls.
> > > >> Also add unlikely().
> > > >>
> > > >> Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls")
> > > >> Signed-off-by: Bixuan Cui<cuibixuan@linux.alibaba.com>
> > > >> ---
> > > >> There are a lot of oversize warnings and patches about kvmalloc()
> > > >> calls recently. Maybe these warnings are not very necessary.
> > > >
> > > > Or maybe they are. Please let's take a look at these warnings,
> > > > one at a time. If a large number of them are bogus then sure,
> > > > let's disable the runtime test. But perhaps it's the case that
> > > > calling code has genuine issues and should be repaired.
> > >
> > > Such as：
> >
> > Thanks, that's helpful.
> >
> > Let's bring all these to the attention of the relevant developers.
> >
> > If the consensus is "the code's fine, the warning is bogus" then let's
> > consider retiring the warning.
> >
> > If the consensus is otherwise then hopefully they will fix their stuff!
> >
> > > https://syzkaller.appspot.com/bug?id=24452f89446639c901ac07379ccc702808471e8e
> >
> > (cc bpf@vger.kernel.org)
> >
> > > https://syzkaller.appspot.com/bug?id=f7c5a86e747f9b7ce333e7295875cd4ede2c7a0d
> >
> > (cc netdev@vger.kernel.org, maintainers)
> >
> > > https://syzkaller.appspot.com/bug?id=8f306f3db150657a1f6bbe1927467084531602c7
> >
> > (cc kvm@vger.kernel.org)
> >
> > > https://syzkaller.appspot.com/bug?id=6f30adb592d476978777a1125d1f680edfc23e00
> >
> > (cc netfilter-devel@vger.kernel.org)
>
> The netfilter bug has since been fixed:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?id=7bbc3d385bd813077acaf0e6fdb2a86a901f5382
How is this a "fix" ?
u32 was the limit and because of the new warn the limit
got reduced to s32.
Every subsystem is supposed to do this "fix" now?
> > > https://syzkaller.appspot.com/bug?id=4c9ab8c7d0f8b551950db06559dc9cde4119ac83
> >
> > (bpf again).
>
> J.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls
2021-12-02 15:34 ` Alexei Starovoitov
@ 2021-12-02 21:16 ` Jeremy Sowden
0 siblings, 0 replies; 6+ messages in thread
From: Jeremy Sowden @ 2021-12-02 21:16 UTC (permalink / raw)
To: Alexei Starovoitov
Cc: Andrew Morton, Bixuan Cui, linux-mm, LKML, Linus Torvalds,
Leon Romanovsky, Willy Tarreau, Kees Cook, bpf,
Network Development, Alexei Starovoitov, Daniel Borkmann,
Jakub Kicinski, kvm, netfilter-devel
[-- Attachment #1: Type: text/plain, Size: 2833 bytes --]
On 2021-12-02, at 07:34:36 -0800, Alexei Starovoitov wrote:
> On Thu, Dec 2, 2021 at 2:38 AM Jeremy Sowden wrote:
> > On 2021-12-01, at 20:29:05 -0800, Andrew Morton wrote:
> > > On Thu, 2 Dec 2021 12:05:15 +0800 Bixuan Cui wrote:
> > > > 在 2021/12/2 上午11:26, Andrew Morton 写道:
> > > > >> Delete the WARN_ON() and return NULL directly for oversized
> > > > >> parameter in kvmalloc() calls.
> > > > >> Also add unlikely().
> > > > >>
> > > > >> Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls")
> > > > >> Signed-off-by: Bixuan Cui<cuibixuan@linux.alibaba.com>
> > > > >> ---
> > > > >> There are a lot of oversize warnings and patches about kvmalloc()
> > > > >> calls recently. Maybe these warnings are not very necessary.
> > > > >
> > > > > Or maybe they are. Please let's take a look at these warnings,
> > > > > one at a time. If a large number of them are bogus then sure,
> > > > > let's disable the runtime test. But perhaps it's the case that
> > > > > calling code has genuine issues and should be repaired.
> > > >
> > > > Such as：
> > >
> > > Thanks, that's helpful.
> > >
> > > Let's bring all these to the attention of the relevant developers.
> > >
> > > If the consensus is "the code's fine, the warning is bogus" then let's
> > > consider retiring the warning.
> > >
> > > If the consensus is otherwise then hopefully they will fix their stuff!
> > >
> > > > https://syzkaller.appspot.com/bug?id=24452f89446639c901ac07379ccc702808471e8e
> > >
> > > (cc bpf@vger.kernel.org)
> > >
> > > > https://syzkaller.appspot.com/bug?id=f7c5a86e747f9b7ce333e7295875cd4ede2c7a0d
> > >
> > > (cc netdev@vger.kernel.org, maintainers)
> > >
> > > > https://syzkaller.appspot.com/bug?id=8f306f3db150657a1f6bbe1927467084531602c7
> > >
> > > (cc kvm@vger.kernel.org)
> > >
> > > > https://syzkaller.appspot.com/bug?id=6f30adb592d476978777a1125d1f680edfc23e00
> > >
> > > (cc netfilter-devel@vger.kernel.org)
> >
> > The netfilter bug has since been fixed:
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?id=7bbc3d385bd813077acaf0e6fdb2a86a901f5382
>
> How is this a "fix" ?
> u32 was the limit and because of the new warn the limit
> got reduced to s32.
> Every subsystem is supposed to do this "fix" now?
My intention was only to provide information about what had been done in
the ipset case. In that case, there was already a check in place to
ensure that the requested hash-table size would not result in integer
overflow, and it was adjusted to reflect the limit imposed by the new
warning (one imagines that there is not much demand for hash-tables that
big).
I'm not familiar with the other cases, and so I would not presume to
make suggestions about whether those warnings were useful.
J.
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls
2021-12-02 4:29 ` [PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls Andrew Morton
2021-12-02 10:38 ` Jeremy Sowden
@ 2021-12-02 11:49 ` Bixuan Cui
2021-12-03 19:37 ` Sean Christopherson
2 siblings, 0 replies; 6+ messages in thread
From: Bixuan Cui @ 2021-12-02 11:49 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-mm, linux-kernel, torvalds, leon, w, keescook, bpf, netdev,
Alexei Starovoitov, Daniel Borkmann, Jakub Kicinski, kvm,
netfilter-devel
在 2021/12/2 下午12:29, Andrew Morton 写道:
> Thanks, that's helpful.
>
> Let's bring all these to the attention of the relevant developers.
>
> If the consensus is "the code's fine, the warning is bogus" then let's
> consider retiring the warning.
>
> If the consensus is otherwise then hopefully they will fix their stuff!
Ok,thanks for your advice :-)
Thanks,
Bixuan Cui
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls
2021-12-02 4:29 ` [PATCH -next] mm: delete oversized WARN_ON() in kvmalloc() calls Andrew Morton
2021-12-02 10:38 ` Jeremy Sowden
2021-12-02 11:49 ` Bixuan Cui
@ 2021-12-03 19:37 ` Sean Christopherson
2 siblings, 0 replies; 6+ messages in thread
From: Sean Christopherson @ 2021-12-03 19:37 UTC (permalink / raw)
To: Andrew Morton
Cc: Bixuan Cui, linux-mm, linux-kernel, torvalds, leon, w, keescook,
bpf, netdev, Alexei Starovoitov, Daniel Borkmann, Jakub Kicinski,
kvm, netfilter-devel, Paolo Bonzini
+Paolo, I'm pretty sure he's still not subscribed to the KVM mailing list :-)
On Wed, Dec 01, 2021, Andrew Morton wrote:
> On Thu, 2 Dec 2021 12:05:15 +0800 Bixuan Cui <cuibixuan@linux.alibaba.com> wrote:
>
> >
> > 在 2021/12/2 上午11:26, Andrew Morton 写道:
> > >> Delete the WARN_ON() and return NULL directly for oversized parameter
> > >> in kvmalloc() calls.
> > >> Also add unlikely().
> > >>
> > >> Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls")
> > >> Signed-off-by: Bixuan Cui<cuibixuan@linux.alibaba.com>
> > >> ---
> > >> There are a lot of oversize warnings and patches about kvmalloc() calls
> > >> recently. Maybe these warnings are not very necessary.
> > > Or maybe they are. Please let's take a look at these warnings, one at
> > > a time. If a large number of them are bogus then sure, let's disable
> > > the runtime test. But perhaps it's the case that calling code has
> > > genuine issues and should be repaired.
> > Such as：
>
> Thanks, that's helpful.
>
> Let's bring all these to the attention of the relevant developers.
>
> If the consensus is "the code's fine, the warning is bogus" then let's
> consider retiring the warning.
>
> If the consensus is otherwise then hopefully they will fix their stuff!
>
>
>
> > https://syzkaller.appspot.com/bug?id=24452f89446639c901ac07379ccc702808471e8e
>
> (cc bpf@vger.kernel.org)
>
> > https://syzkaller.appspot.com/bug?id=f7c5a86e747f9b7ce333e7295875cd4ede2c7a0d
>
> (cc netdev@vger.kernel.org, maintainers)
>
> > https://syzkaller.appspot.com/bug?id=8f306f3db150657a1f6bbe1927467084531602c7
>
> (cc kvm@vger.kernel.org)
Paolo posted patches to resolve the KVM issues, but I don't think they ever got
applied.
https://lore.kernel.org/all/20211016064302.165220-1-pbonzini@redhat.com/
https://lore.kernel.org/all/20211015165519.135670-1-pbonzini@redhat.com/
^ permalink raw reply [flat|nested] 6+ messages in thread