| Message ID | 20240506123032.3351895-1-edumazet@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 445c0b69c72903528fdf0b34015b5b9142062c4b |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next] mptcp: fix possible NULL dereferences | expand |
On Mon, 2024-05-06 at 12:30 +0000, Eric Dumazet wrote: > subflow_add_reset_reason(skb, ...) can fail. whooops... yes, indeed. > We can not assume mptcp_get_ext(skb) always return a non NULL pointer. > > syzbot reported: > > general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI > KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] > CPU: 0 PID: 5098 Comm: syz-executor132 Not tainted 6.9.0-rc6-syzkaller-01478-gcdc74c9d06e7 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 > RIP: 0010:subflow_v6_route_req+0x2c7/0x490 net/mptcp/subflow.c:388 > Code: 8d 7b 07 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 c0 01 00 00 0f b6 43 07 48 8d 1c c3 48 83 c3 18 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 84 01 00 00 0f b6 5b 01 83 e3 0f 48 89 > RSP: 0018:ffffc9000362eb68 EFLAGS: 00010206 > RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff888022039e00 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffff88807d961140 R08: ffffffff8b6cb76b R09: 1ffff1100fb2c230 > R10: dffffc0000000000 R11: ffffed100fb2c231 R12: dffffc0000000000 > R13: ffff888022bfe273 R14: ffff88802cf9cc80 R15: ffff88802ad5a700 > FS: 0000555587ad2380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f420c3f9720 CR3: 0000000022bfc000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > tcp_conn_request+0xf07/0x32c0 net/ipv4/tcp_input.c:7180 > tcp_rcv_state_process+0x183c/0x4500 net/ipv4/tcp_input.c:6663 > tcp_v6_do_rcv+0x8b2/0x1310 net/ipv6/tcp_ipv6.c:1673 > tcp_v6_rcv+0x22b4/0x30b0 net/ipv6/tcp_ipv6.c:1910 > ip6_protocol_deliver_rcu+0xc76/0x1570 net/ipv6/ip6_input.c:438 > ip6_input_finish+0x186/0x2d0 net/ipv6/ip6_input.c:483 > NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 > NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 > __netif_receive_skb_one_core net/core/dev.c:5625 [inline] > __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5739 > netif_receive_skb_internal net/core/dev.c:5825 [inline] > netif_receive_skb+0x1e8/0x890 net/core/dev.c:5885 > tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1549 > tun_get_user+0x2f35/0x4560 drivers/net/tun.c:2002 > tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2048 > call_write_iter include/linux/fs.h:2110 [inline] > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa84/0xcb0 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > Fixes: 3e140491dd80 ("mptcp: support rstreason for passive reset") > Reported-by: syzbot <syzkaller@googlegroups.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Jason Xing <kernelxing@tencent.com> > Cc: Matthieu Baerts (NGI0) <matttbe@kernel.org> > Cc: Paolo Abeni <pabeni@redhat.com> LGTM, thanks! Acked-by: Paolo Abeni <pabeni@redhat.com>
Hi Eric, (+cc MPTCP ML for the CI, patch tracking, and other devs) On 06/05/2024 14:30, Eric Dumazet wrote: > subflow_add_reset_reason(skb, ...) can fail. > > We can not assume mptcp_get_ext(skb) always return a non NULL pointer. Good catch! Thank you for the fix! It looks good to me: Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Cheers, Matt
On Mon, May 6, 2024 at 8:36 PM Eric Dumazet <edumazet@google.com> wrote: > > subflow_add_reset_reason(skb, ...) can fail. > > We can not assume mptcp_get_ext(skb) always return a non NULL pointer. > > syzbot reported: > > general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI > KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] > CPU: 0 PID: 5098 Comm: syz-executor132 Not tainted 6.9.0-rc6-syzkaller-01478-gcdc74c9d06e7 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 > RIP: 0010:subflow_v6_route_req+0x2c7/0x490 net/mptcp/subflow.c:388 > Code: 8d 7b 07 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 c0 01 00 00 0f b6 43 07 48 8d 1c c3 48 83 c3 18 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 84 01 00 00 0f b6 5b 01 83 e3 0f 48 89 > RSP: 0018:ffffc9000362eb68 EFLAGS: 00010206 > RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff888022039e00 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffff88807d961140 R08: ffffffff8b6cb76b R09: 1ffff1100fb2c230 > R10: dffffc0000000000 R11: ffffed100fb2c231 R12: dffffc0000000000 > R13: ffff888022bfe273 R14: ffff88802cf9cc80 R15: ffff88802ad5a700 > FS: 0000555587ad2380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f420c3f9720 CR3: 0000000022bfc000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > tcp_conn_request+0xf07/0x32c0 net/ipv4/tcp_input.c:7180 > tcp_rcv_state_process+0x183c/0x4500 net/ipv4/tcp_input.c:6663 > tcp_v6_do_rcv+0x8b2/0x1310 net/ipv6/tcp_ipv6.c:1673 > tcp_v6_rcv+0x22b4/0x30b0 net/ipv6/tcp_ipv6.c:1910 > ip6_protocol_deliver_rcu+0xc76/0x1570 net/ipv6/ip6_input.c:438 > ip6_input_finish+0x186/0x2d0 net/ipv6/ip6_input.c:483 > NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 > NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 > __netif_receive_skb_one_core net/core/dev.c:5625 [inline] > __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5739 > netif_receive_skb_internal net/core/dev.c:5825 [inline] > netif_receive_skb+0x1e8/0x890 net/core/dev.c:5885 > tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1549 > tun_get_user+0x2f35/0x4560 drivers/net/tun.c:2002 > tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2048 > call_write_iter include/linux/fs.h:2110 [inline] > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa84/0xcb0 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > Fixes: 3e140491dd80 ("mptcp: support rstreason for passive reset") > Reported-by: syzbot <syzkaller@googlegroups.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Jason Xing <kernelxing@tencent.com> > Cc: Matthieu Baerts (NGI0) <matttbe@kernel.org> > Cc: Paolo Abeni <pabeni@redhat.com> Sorry, and thank you for the fix. Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> > --- > net/mptcp/subflow.c | 32 +++++++++++++++++--------------- > 1 file changed, 17 insertions(+), 15 deletions(-) > > diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c > index 97ec44d1df308f53e8ebabe6f77c8c86859b5a36..7208d824be353476496271e971ccafde1a47b959 100644 > --- a/net/mptcp/subflow.c > +++ b/net/mptcp/subflow.c > @@ -287,6 +287,16 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req, > } > EXPORT_SYMBOL_GPL(mptcp_subflow_init_cookie_req); > > +static enum sk_rst_reason mptcp_get_rst_reason(const struct sk_buff *skb) > +{ > + const struct mptcp_ext *mpext = mptcp_get_ext(skb); > + > + if (!mpext) > + return SK_RST_REASON_NOT_SPECIFIED; > + > + return sk_rst_convert_mptcp_reason(mpext->reset_reason); > +} > + > static struct dst_entry *subflow_v4_route_req(const struct sock *sk, > struct sk_buff *skb, > struct flowi *fl, > @@ -308,13 +318,9 @@ static struct dst_entry *subflow_v4_route_req(const struct sock *sk, > return dst; > > dst_release(dst); > - if (!req->syncookie) { > - struct mptcp_ext *mpext = mptcp_get_ext(skb); > - enum sk_rst_reason reason; > - > - reason = sk_rst_convert_mptcp_reason(mpext->reset_reason); > - tcp_request_sock_ops.send_reset(sk, skb, reason); > - } > + if (!req->syncookie) > + tcp_request_sock_ops.send_reset(sk, skb, > + mptcp_get_rst_reason(skb)); > return NULL; > } > > @@ -381,13 +387,9 @@ static struct dst_entry *subflow_v6_route_req(const struct sock *sk, > return dst; > > dst_release(dst); > - if (!req->syncookie) { > - struct mptcp_ext *mpext = mptcp_get_ext(skb); > - enum sk_rst_reason reason; > - > - reason = sk_rst_convert_mptcp_reason(mpext->reset_reason); > - tcp6_request_sock_ops.send_reset(sk, skb, reason); > - } > + if (!req->syncookie) > + tcp6_request_sock_ops.send_reset(sk, skb, > + mptcp_get_rst_reason(skb)); > return NULL; > } > #endif > @@ -923,7 +925,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, > tcp_rsk(req)->drop_req = true; > inet_csk_prepare_for_destroy_sock(child); > tcp_done(child); > - reason = sk_rst_convert_mptcp_reason(mptcp_get_ext(skb)->reset_reason); > + reason = mptcp_get_rst_reason(skb); > req->rsk_ops->send_reset(sk, skb, reason); > > /* The last child reference will be released by the caller */ > -- > 2.45.0.rc1.225.g2a3ae87e7f-goog > >
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Mon, 6 May 2024 12:30:32 +0000 you wrote: > subflow_add_reset_reason(skb, ...) can fail. > > We can not assume mptcp_get_ext(skb) always return a non NULL pointer. > > syzbot reported: > > general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI > KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] > CPU: 0 PID: 5098 Comm: syz-executor132 Not tainted 6.9.0-rc6-syzkaller-01478-gcdc74c9d06e7 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 > RIP: 0010:subflow_v6_route_req+0x2c7/0x490 net/mptcp/subflow.c:388 > Code: 8d 7b 07 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 c0 01 00 00 0f b6 43 07 48 8d 1c c3 48 83 c3 18 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 84 01 00 00 0f b6 5b 01 83 e3 0f 48 89 > RSP: 0018:ffffc9000362eb68 EFLAGS: 00010206 > RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff888022039e00 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffff88807d961140 R08: ffffffff8b6cb76b R09: 1ffff1100fb2c230 > R10: dffffc0000000000 R11: ffffed100fb2c231 R12: dffffc0000000000 > R13: ffff888022bfe273 R14: ffff88802cf9cc80 R15: ffff88802ad5a700 > FS: 0000555587ad2380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f420c3f9720 CR3: 0000000022bfc000 CR4: 00000000003506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > tcp_conn_request+0xf07/0x32c0 net/ipv4/tcp_input.c:7180 > tcp_rcv_state_process+0x183c/0x4500 net/ipv4/tcp_input.c:6663 > tcp_v6_do_rcv+0x8b2/0x1310 net/ipv6/tcp_ipv6.c:1673 > tcp_v6_rcv+0x22b4/0x30b0 net/ipv6/tcp_ipv6.c:1910 > ip6_protocol_deliver_rcu+0xc76/0x1570 net/ipv6/ip6_input.c:438 > ip6_input_finish+0x186/0x2d0 net/ipv6/ip6_input.c:483 > NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 > NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 > __netif_receive_skb_one_core net/core/dev.c:5625 [inline] > __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5739 > netif_receive_skb_internal net/core/dev.c:5825 [inline] > netif_receive_skb+0x1e8/0x890 net/core/dev.c:5885 > tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1549 > tun_get_user+0x2f35/0x4560 drivers/net/tun.c:2002 > tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2048 > call_write_iter include/linux/fs.h:2110 [inline] > new_sync_write fs/read_write.c:497 [inline] > vfs_write+0xa84/0xcb0 fs/read_write.c:590 > ksys_write+0x1a0/0x2c0 fs/read_write.c:643 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > [...] Here is the summary with links: - [net-next] mptcp: fix possible NULL dereferences https://git.kernel.org/netdev/net-next/c/445c0b69c729 You are awesome, thank you!
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 97ec44d1df308f53e8ebabe6f77c8c86859b5a36..7208d824be353476496271e971ccafde1a47b959 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -287,6 +287,16 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req, } EXPORT_SYMBOL_GPL(mptcp_subflow_init_cookie_req); +static enum sk_rst_reason mptcp_get_rst_reason(const struct sk_buff *skb) +{ + const struct mptcp_ext *mpext = mptcp_get_ext(skb); + + if (!mpext) + return SK_RST_REASON_NOT_SPECIFIED; + + return sk_rst_convert_mptcp_reason(mpext->reset_reason); +} + static struct dst_entry *subflow_v4_route_req(const struct sock *sk, struct sk_buff *skb, struct flowi *fl, @@ -308,13 +318,9 @@ static struct dst_entry *subflow_v4_route_req(const struct sock *sk, return dst; dst_release(dst); - if (!req->syncookie) { - struct mptcp_ext *mpext = mptcp_get_ext(skb); - enum sk_rst_reason reason; - - reason = sk_rst_convert_mptcp_reason(mpext->reset_reason); - tcp_request_sock_ops.send_reset(sk, skb, reason); - } + if (!req->syncookie) + tcp_request_sock_ops.send_reset(sk, skb, + mptcp_get_rst_reason(skb)); return NULL; } @@ -381,13 +387,9 @@ static struct dst_entry *subflow_v6_route_req(const struct sock *sk, return dst; dst_release(dst); - if (!req->syncookie) { - struct mptcp_ext *mpext = mptcp_get_ext(skb); - enum sk_rst_reason reason; - - reason = sk_rst_convert_mptcp_reason(mpext->reset_reason); - tcp6_request_sock_ops.send_reset(sk, skb, reason); - } + if (!req->syncookie) + tcp6_request_sock_ops.send_reset(sk, skb, + mptcp_get_rst_reason(skb)); return NULL; } #endif @@ -923,7 +925,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, tcp_rsk(req)->drop_req = true; inet_csk_prepare_for_destroy_sock(child); tcp_done(child); - reason = sk_rst_convert_mptcp_reason(mptcp_get_ext(skb)->reset_reason); + reason = mptcp_get_rst_reason(skb); req->rsk_ops->send_reset(sk, skb, reason); /* The last child reference will be released by the caller */
subflow_add_reset_reason(skb, ...) can fail. We can not assume mptcp_get_ext(skb) always return a non NULL pointer. syzbot reported: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] CPU: 0 PID: 5098 Comm: syz-executor132 Not tainted 6.9.0-rc6-syzkaller-01478-gcdc74c9d06e7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:subflow_v6_route_req+0x2c7/0x490 net/mptcp/subflow.c:388 Code: 8d 7b 07 48 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 c0 01 00 00 0f b6 43 07 48 8d 1c c3 48 83 c3 18 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 84 01 00 00 0f b6 5b 01 83 e3 0f 48 89 RSP: 0018:ffffc9000362eb68 EFLAGS: 00010206 RAX: 0000000000000003 RBX: 0000000000000018 RCX: ffff888022039e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88807d961140 R08: ffffffff8b6cb76b R09: 1ffff1100fb2c230 R10: dffffc0000000000 R11: ffffed100fb2c231 R12: dffffc0000000000 R13: ffff888022bfe273 R14: ffff88802cf9cc80 R15: ffff88802ad5a700 FS: 0000555587ad2380(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f420c3f9720 CR3: 0000000022bfc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> tcp_conn_request+0xf07/0x32c0 net/ipv4/tcp_input.c:7180 tcp_rcv_state_process+0x183c/0x4500 net/ipv4/tcp_input.c:6663 tcp_v6_do_rcv+0x8b2/0x1310 net/ipv6/tcp_ipv6.c:1673 tcp_v6_rcv+0x22b4/0x30b0 net/ipv6/tcp_ipv6.c:1910 ip6_protocol_deliver_rcu+0xc76/0x1570 net/ipv6/ip6_input.c:438 ip6_input_finish+0x186/0x2d0 net/ipv6/ip6_input.c:483 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5625 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5739 netif_receive_skb_internal net/core/dev.c:5825 [inline] netif_receive_skb+0x1e8/0x890 net/core/dev.c:5885 tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1549 tun_get_user+0x2f35/0x4560 drivers/net/tun.c:2002 tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa84/0xcb0 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 3e140491dd80 ("mptcp: support rstreason for passive reset") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jason Xing <kernelxing@tencent.com> Cc: Matthieu Baerts (NGI0) <matttbe@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> --- net/mptcp/subflow.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-)