| Message ID | 3334d00d8b2faecafdfab9aa593efcbf61442756.1608584474.git.dcaratti@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [net] net: mptcp: cap forward allocation to 1M | expand |
Hello: This patch was applied to netdev/net.git (refs/heads/master): On Mon, 21 Dec 2020 22:07:25 +0100 you wrote: > the following syzkaller reproducer: > > r0 = socket$inet_mptcp(0x2, 0x1, 0x106) > bind$inet(r0, &(0x7f0000000080)={0x2, 0x4e24, @multicast2}, 0x10) > connect$inet(r0, &(0x7f0000000480)={0x2, 0x4e24, @local}, 0x10) > sendto$inet(r0, &(0x7f0000000100)="f6", 0xffffffe7, 0xc000, 0x0, 0x0) > > [...] Here is the summary with links: - [net] net: mptcp: cap forward allocation to 1M https://git.kernel.org/netdev/net/c/e7579d5d5b32 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 09b19aa2f205..6628d8d74203 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -877,6 +877,9 @@ static void __mptcp_wmem_reserve(struct sock *sk, int size) struct mptcp_sock *msk = mptcp_sk(sk); WARN_ON_ONCE(msk->wmem_reserved); + if (WARN_ON_ONCE(amount < 0)) + amount = 0; + if (amount <= sk->sk_forward_alloc) goto reserve; @@ -1587,7 +1590,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) if (msg->msg_flags & ~(MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL)) return -EOPNOTSUPP; - mptcp_lock_sock(sk, __mptcp_wmem_reserve(sk, len)); + mptcp_lock_sock(sk, __mptcp_wmem_reserve(sk, min_t(size_t, 1 << 20, len))); timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
the following syzkaller reproducer: r0 = socket$inet_mptcp(0x2, 0x1, 0x106) bind$inet(r0, &(0x7f0000000080)={0x2, 0x4e24, @multicast2}, 0x10) connect$inet(r0, &(0x7f0000000480)={0x2, 0x4e24, @local}, 0x10) sendto$inet(r0, &(0x7f0000000100)="f6", 0xffffffe7, 0xc000, 0x0, 0x0) systematically triggers the following warning: WARNING: CPU: 2 PID: 8618 at net/core/stream.c:208 sk_stream_kill_queues+0x3fa/0x580 Modules linked in: CPU: 2 PID: 8618 Comm: syz-executor Not tainted 5.10.0+ #334 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/04 RIP: 0010:sk_stream_kill_queues+0x3fa/0x580 Code: df 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 40 8b ab 20 02 00 00 e9 64 ff ff ff e8 df f0 81 2 RSP: 0018:ffffc9000290fcb0 EFLAGS: 00010293 RAX: ffff888011cb8000 RBX: 0000000000000000 RCX: ffffffff86eecf0e RDX: 0000000000000000 RSI: ffffffff86eecf6a RDI: 0000000000000005 RBP: 0000000000000e28 R08: ffff888011cb8000 R09: fffffbfff1f48139 R10: ffffffff8fa409c7 R11: fffffbfff1f48138 R12: ffff8880215e6220 R13: ffffffff8fa409c0 R14: ffffc9000290fd30 R15: 1ffff92000521fa2 FS: 00007f41c78f4800(0000) GS:ffff88802d000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f95c803d088 CR3: 0000000025ed2000 CR4: 00000000000006f0 Call Trace: __mptcp_destroy_sock+0x4f5/0x8e0 mptcp_close+0x5e2/0x7f0 inet_release+0x12b/0x270 __sock_release+0xc8/0x270 sock_close+0x18/0x20 __fput+0x272/0x8e0 task_work_run+0xe0/0x1a0 exit_to_user_mode_prepare+0x1df/0x200 syscall_exit_to_user_mode+0x19/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 userspace programs provide arbitrarily high values of 'len' in sendmsg(): this is causing integer overflow of 'amount'. Cap forward allocation to 1 megabyte: higher values are not really useful. Suggested-by: Paolo Abeni <pabeni@redhat.com> Fixes: e93da92896bc ("mptcp: implement wmem reservation") Signed-off-by: Davide Caratti <dcaratti@redhat.com> --- net/mptcp/protocol.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)