On Wed, Dec 16, 2015 at 4:57 PM, Vegard Nossum <vegard.nos...@oracle.com> wrote: > If you create a raw socket with a protocol of e.g. 0x10000, then > inet_sk(sk)->inet_num will get set to 0 since it only has room for 16 > bits. This causes problems further down the line as lots of code makes > assumptions about ->inet_num, for example connect()...inet_autobind() > will attempt to call sk->sk_prot->get_port() which is invalid: > > BUG: unable to handle kernel NULL pointer dereference at (null) > IP: [< (null)>] (null) > PGD 19ea0067 PUD 19d3f067 PMD 0 > Oops: 0010 [#1] SMP > CPU: 1 PID: 849 Comm: a.out Not tainted 4.4.0-rc4+ #287 > task: ffff880019a12640 ti: ffff88000008c000 task.ti: ffff88000008c000 > RIP: 0010:[<0000000000000000>] [< (null)>] (null) > RSP: 0018:ffff88000008fe50 EFLAGS: 00010246 > RAX: ffffffff81cc61f0 RBX: ffff880019d2ca80 RCX: 0000000000000802 > RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff880019d2ca80 > RBP: ffff88000008fe60 R08: 00007f0e6b132e80 R09: ffff880019d2ca80 > R10: ffff88001a7a72e0 R11: ffff880019a12640 R12: 000000000000000b > R13: 0000000000400644 R14: 0000000000000000 R15: 0000000000000000 > FS: 00007f0e6b355740(0000) GS:ffff88001a900000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000000 CR3: 0000000019d3d000 CR4: 00000000001406a0 > Stack: > ffffffff815f1c69 ffff880019d2ca80 ffff88000008fe88 ffffffff815f1cde > 0000000b0000000b ffff88000008fea0 ffff880019484000 ffff88000008ff38 > ffffffff8156f310 0000000000000000 2a2a2a2a2a2a2a2a ffffffff8100002a > Call Trace: > [<ffffffff815f1c69>] ? inet_autobind+0x23/0x50 > [<ffffffff815f1cde>] inet_dgram_connect+0x48/0x64 > [<ffffffff8156f310>] SYSC_connect+0x84/0xae > [<ffffffff8156f3ed>] ? sock_alloc_file+0xb3/0x108 > [<ffffffff81132021>] ? fd_install+0x20/0x22 > [<ffffffff815700d2>] ? SYSC_socket+0x62/0x90 > [<ffffffff81570318>] SyS_connect+0x9/0xb > [<ffffffff816fb86e>] entry_SYSCALL_64_fastpath+0x12/0x71 > Code: Bad RIP value. > RIP [< (null)>] (null) > RSP <ffff88000008fe50> > CR2: 0000000000000000 > ---[ end trace bd60b4fe2edc2537 ]--- > > Signed-off-by: Vegard Nossum <vegard.nos...@oracle.com> > Cc: Eric Dumazet <eduma...@google.com> > Cc: <sta...@vger.kernel.org> > --- > net/ipv4/af_inet.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git net/ipv4/af_inet.c net/ipv4/af_inet.c > index 11c4ca1..4e1583a 100644 > --- net/ipv4/af_inet.c > +++ net/ipv4/af_inet.c > @@ -316,6 +316,12 @@ lookup_protocol: > > WARN_ON(!answer_prot->slab); > > + /* Check that the protocol we were given will actually fit in > + * inet->inet_num. */ > + err = -EINVAL; > + if (protocol != (typeof(inet->inet_num)) protocol) > + goto out; > + > err = -ENOBUFS; > sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern); > if (!sk) > -- > 1.9.1 >
It looks already fixed in a better way (IPv6, ...) http://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=79462ad02e861803b3840cc782248c7359451cd9 Thanks -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
