| Message ID | 20201019172532.3906-1-saeed.mirzamohammadi@oracle.com |
|---|---|
| State | Accepted |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | [linux-5.9,1/1] net: netfilter: fix KASAN: slab-out-of-bounds Read in nft_flow_rule_create | expand |
On Mon, Oct 19, 2020 at 10:25:32AM -0700, saeed.mirzamohammadi@oracle.com wrote: > From: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> > > This patch fixes the issue due to: > > BUG: KASAN: slab-out-of-bounds in nft_flow_rule_create+0x622/0x6a2 > net/netfilter/nf_tables_offload.c:40 > Read of size 8 at addr ffff888103910b58 by task syz-executor227/16244 > > The error happens when expr->ops is accessed early on before performing the boundary check and after nft_expr_next() moves the expr to go out-of-bounds. > > This patch checks the boundary condition before expr->ops that fixes the slab-out-of-bounds Read issue. Thanks. I made a slight variant of your patch. I'm attaching it, it is also fixing the problem but it introduced nft_expr_more() and use it everywhere. Let me know if this looks fine to you.
Thanks! Yes, that looks good to me. Saeed > On Oct 20, 2020, at 4:50 AM, Pablo Neira Ayuso <pablo@netfilter.org> wrote: > > On Mon, Oct 19, 2020 at 10:25:32AM -0700, saeed.mirzamohammadi@oracle.com wrote: >> From: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> >> >> This patch fixes the issue due to: >> >> BUG: KASAN: slab-out-of-bounds in nft_flow_rule_create+0x622/0x6a2 >> net/netfilter/nf_tables_offload.c:40 >> Read of size 8 at addr ffff888103910b58 by task syz-executor227/16244 >> >> The error happens when expr->ops is accessed early on before performing the boundary check and after nft_expr_next() moves the expr to go out-of-bounds. >> >> This patch checks the boundary condition before expr->ops that fixes the slab-out-of-bounds Read issue. > > Thanks. I made a slight variant of your patch. > > I'm attaching it, it is also fixing the problem but it introduced > nft_expr_more() and use it everywhere. > > Let me know if this looks fine to you. > <0001-netfilter-fix-KASAN-slab-out-of-bounds-Read-in-nft_f.patch>
Attached the syzkaller C repro. Tested-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> > On Oct 20, 2020, at 9:45 AM, Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> wrote: > > Thanks! Yes, that looks good to me. > > Saeed > >> On Oct 20, 2020, at 4:50 AM, Pablo Neira Ayuso <pablo@netfilter.org> wrote: >> >> On Mon, Oct 19, 2020 at 10:25:32AM -0700, saeed.mirzamohammadi@oracle.com wrote: >>> From: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> >>> >>> This patch fixes the issue due to: >>> >>> BUG: KASAN: slab-out-of-bounds in nft_flow_rule_create+0x622/0x6a2 >>> net/netfilter/nf_tables_offload.c:40 >>> Read of size 8 at addr ffff888103910b58 by task syz-executor227/16244 >>> >>> The error happens when expr->ops is accessed early on before performing the boundary check and after nft_expr_next() moves the expr to go out-of-bounds. >>> >>> This patch checks the boundary condition before expr->ops that fixes the slab-out-of-bounds Read issue. >> >> Thanks. I made a slight variant of your patch. >> >> I'm attaching it, it is also fixing the problem but it introduced >> nft_expr_more() and use it everywhere. >> >> Let me know if this looks fine to you. >> <0001-netfilter-fix-KASAN-slab-out-of-bounds-Read-in-nft_f.patch> >
Adding stable. > On Oct 21, 2020, at 1:08 PM, Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> wrote: > > Attached the syzkaller C repro. > > Tested-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> > <repro.c> >> On Oct 20, 2020, at 9:45 AM, Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> wrote: >> >> Thanks! Yes, that looks good to me. >> >> Saeed >> >>> On Oct 20, 2020, at 4:50 AM, Pablo Neira Ayuso <pablo@netfilter.org> wrote: >>> >>> On Mon, Oct 19, 2020 at 10:25:32AM -0700, saeed.mirzamohammadi@oracle.com wrote: >>>> From: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> >>>> >>>> This patch fixes the issue due to: >>>> >>>> BUG: KASAN: slab-out-of-bounds in nft_flow_rule_create+0x622/0x6a2 >>>> net/netfilter/nf_tables_offload.c:40 >>>> Read of size 8 at addr ffff888103910b58 by task syz-executor227/16244 >>>> >>>> The error happens when expr->ops is accessed early on before performing the boundary check and after nft_expr_next() moves the expr to go out-of-bounds. >>>> >>>> This patch checks the boundary condition before expr->ops that fixes the slab-out-of-bounds Read issue. >>> >>> Thanks. I made a slight variant of your patch. >>> >>> I'm attaching it, it is also fixing the problem but it introduced >>> nft_expr_more() and use it everywhere. >>> >>> Let me know if this looks fine to you. >>> <0001-netfilter-fix-KASAN-slab-out-of-bounds-Read-in-nft_f.patch> >> >
On Sun, Oct 25, 2020 at 04:31:57PM -0700, Saeed Mirzamohammadi wrote:
> Adding stable.
What did that do?
confused,
greg k-h
Greg KH <gregkh@linuxfoundation.org> wrote: [ Trimming CC ] > On Sun, Oct 25, 2020 at 04:31:57PM -0700, Saeed Mirzamohammadi wrote: > > Adding stable. > > What did that do? Its a request to pick up commit 31cc578ae2de19c748af06d859019dced68e325d Author: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> Date: Tue Oct 20 13:41:36 2020 +0200 netfilter: nftables_offload: KASAN slab-out-of-bounds Read in nft_flow_rule_create Which lacks a Fixes tag. Should have been: Fixes: c9626a2cbdb20e2 ("netfilter: nf_tables: add hardware offload support") (v5.3+) Hope that makes things clearer.
On Tue, Oct 27, 2020 at 07:42:26AM +0100, Florian Westphal wrote: > Greg KH <gregkh@linuxfoundation.org> wrote: > > [ Trimming CC ] > > > On Sun, Oct 25, 2020 at 04:31:57PM -0700, Saeed Mirzamohammadi wrote: > > > Adding stable. > > > > What did that do? > > Its a request to pick up > > commit 31cc578ae2de19c748af06d859019dced68e325d > Author: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com> > Date: Tue Oct 20 13:41:36 2020 +0200 > > netfilter: nftables_offload: KASAN slab-out-of-bounds Read in nft_flow_rule_create > > Which lacks a Fixes tag. Should have been: > > Fixes: c9626a2cbdb20e2 ("netfilter: nf_tables: add hardware offload support") > (v5.3+) > > Hope that makes things clearer. That makes it much more obvious and clearer, thank you. Saeed, please be more explicit in the future. thanks, greg k-h
Hi Greg, On Tue, Oct 27, 2020 at 07:21:11AM +0100, Greg KH wrote: > On Sun, Oct 25, 2020 at 04:31:57PM -0700, Saeed Mirzamohammadi wrote: > > Adding stable. > > What did that do? Saeed is requesting that stable maintainers cherry-picks this patch: 31cc578ae2de ("netfilter: nftables_offload: KASAN slab-out-of-bounds Read in nft_flow_rule_create") into stable 5.4 and 5.8. Thanks.
On Tue, Oct 27, 2020 at 09:19:22AM +0100, Pablo Neira Ayuso wrote: > Hi Greg, > > On Tue, Oct 27, 2020 at 07:21:11AM +0100, Greg KH wrote: > > On Sun, Oct 25, 2020 at 04:31:57PM -0700, Saeed Mirzamohammadi wrote: > > > Adding stable. > > > > What did that do? > > Saeed is requesting that stable maintainers cherry-picks this patch: > > 31cc578ae2de ("netfilter: nftables_offload: KASAN slab-out-of-bounds > Read in nft_flow_rule_create") > > into stable 5.4 and 5.8. 5.9 is also a stable kernel :) Will go queue it up everywhere... thanks, greg k-h
On Thu, Oct 29, 2020 at 12:02:41PM +0100, Greg KH wrote: > On Tue, Oct 27, 2020 at 09:19:22AM +0100, Pablo Neira Ayuso wrote: > > Hi Greg, > > > > On Tue, Oct 27, 2020 at 07:21:11AM +0100, Greg KH wrote: > > > On Sun, Oct 25, 2020 at 04:31:57PM -0700, Saeed Mirzamohammadi wrote: > > > > Adding stable. > > > > > > What did that do? > > > > Saeed is requesting that stable maintainers cherry-picks this patch: > > > > 31cc578ae2de ("netfilter: nftables_offload: KASAN slab-out-of-bounds > > Read in nft_flow_rule_create") > > > > into stable 5.4 and 5.8. > > 5.9 is also a stable kernel :) Oh, indeed, I forgot this one :) > Will go queue it up everywhere... Thanks.
diff --git a/net/netfilter/nf_tables_offload.c b/net/netfilter/nf_tables_offload.c index 9ef37c1b7b3b..1273e3c0d4b8 100644 --- a/net/netfilter/nf_tables_offload.c +++ b/net/netfilter/nf_tables_offload.c @@ -37,7 +37,7 @@ struct nft_flow_rule *nft_flow_rule_create(struct net *net, struct nft_expr *expr; expr = nft_expr_first(rule); - while (expr->ops && expr != nft_expr_last(rule)) { + while (expr != nft_expr_last(rule) && expr->ops) { if (expr->ops->offload_flags & NFT_OFFLOAD_F_ACTION) num_actions++; @@ -61,7 +61,7 @@ struct nft_flow_rule *nft_flow_rule_create(struct net *net, ctx->net = net; ctx->dep.type = NFT_OFFLOAD_DEP_UNSPEC; - while (expr->ops && expr != nft_expr_last(rule)) { + while (expr != nft_expr_last(rule) && expr->ops) { if (!expr->ops->offload) { err = -EOPNOTSUPP; goto err_out;