| From foo@baz Sat 16 May 2020 02:04:40 PM CEST |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Thu, 14 May 2020 13:58:13 -0700 |
| Subject: tcp: fix error recovery in tcp_zerocopy_receive() |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| [ Upstream commit e776af608f692a7a647455106295fa34469e7475 ] |
| |
| If user provides wrong virtual address in TCP_ZEROCOPY_RECEIVE |
| operation we want to return -EINVAL error. |
| |
| But depending on zc->recv_skip_hint content, we might return |
| -EIO error if the socket has SOCK_DONE set. |
| |
| Make sure to return -EINVAL in this case. |
| |
| BUG: KMSAN: uninit-value in tcp_zerocopy_receive net/ipv4/tcp.c:1833 [inline] |
| BUG: KMSAN: uninit-value in do_tcp_getsockopt+0x4494/0x6320 net/ipv4/tcp.c:3685 |
| CPU: 1 PID: 625 Comm: syz-executor.0 Not tainted 5.7.0-rc4-syzkaller #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 |
| Call Trace: |
| __dump_stack lib/dump_stack.c:77 [inline] |
| dump_stack+0x1c9/0x220 lib/dump_stack.c:118 |
| kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 |
| __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 |
| tcp_zerocopy_receive net/ipv4/tcp.c:1833 [inline] |
| do_tcp_getsockopt+0x4494/0x6320 net/ipv4/tcp.c:3685 |
| tcp_getsockopt+0xf8/0x1f0 net/ipv4/tcp.c:3728 |
| sock_common_getsockopt+0x13f/0x180 net/core/sock.c:3131 |
| __sys_getsockopt+0x533/0x7b0 net/socket.c:2177 |
| __do_sys_getsockopt net/socket.c:2192 [inline] |
| __se_sys_getsockopt+0xe1/0x100 net/socket.c:2189 |
| __x64_sys_getsockopt+0x62/0x80 net/socket.c:2189 |
| do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 |
| entry_SYSCALL_64_after_hwframe+0x44/0xa9 |
| RIP: 0033:0x45c829 |
| Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 |
| RSP: 002b:00007f1deeb72c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 |
| RAX: ffffffffffffffda RBX: 00000000004e01e0 RCX: 000000000045c829 |
| RDX: 0000000000000023 RSI: 0000000000000006 RDI: 0000000000000009 |
| RBP: 000000000078bf00 R08: 0000000020000200 R09: 0000000000000000 |
| R10: 00000000200001c0 R11: 0000000000000246 R12: 00000000ffffffff |
| R13: 00000000000001d8 R14: 00000000004d3038 R15: 00007f1deeb736d4 |
| |
| Local variable ----zc@do_tcp_getsockopt created at: |
| do_tcp_getsockopt+0x1a74/0x6320 net/ipv4/tcp.c:3670 |
| do_tcp_getsockopt+0x1a74/0x6320 net/ipv4/tcp.c:3670 |
| |
| Fixes: 05255b823a61 ("tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive") |
| Signed-off-by: Eric Dumazet <edumazet@google.com> |
| Reported-by: syzbot <syzkaller@googlegroups.com> |
| Acked-by: Soheil Hassas Yeganeh <soheil@google.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/ipv4/tcp.c | 7 ++++--- |
| 1 file changed, 4 insertions(+), 3 deletions(-) |
| |
| --- a/net/ipv4/tcp.c |
| +++ b/net/ipv4/tcp.c |
| @@ -1756,10 +1756,11 @@ static int tcp_zerocopy_receive(struct s |
| |
| down_read(¤t->mm->mmap_sem); |
| |
| - ret = -EINVAL; |
| vma = find_vma(current->mm, address); |
| - if (!vma || vma->vm_start > address || vma->vm_ops != &tcp_vm_ops) |
| - goto out; |
| + if (!vma || vma->vm_start > address || vma->vm_ops != &tcp_vm_ops) { |
| + up_read(¤t->mm->mmap_sem); |
| + return -EINVAL; |
| + } |
| zc->length = min_t(unsigned long, zc->length, vma->vm_end - address); |
| |
| tp = tcp_sk(sk); |