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authorEric Dumazet <edumazet@google.com>2021-03-01 21:29:17 +0300
committerDavid S. Miller <davem@davemloft.net>2021-03-02 02:32:05 +0300
commit8811f4a9836e31c14ecdf79d9f3cb7c5d463265d (patch)
treea2e30c261cccb808ed5795599036e9ca7ce79505 /net
parent3946688edbc5b629110c339b3babf10aa9e7adad (diff)
downloadlinux-8811f4a9836e31c14ecdf79d9f3cb7c5d463265d.tar.xz
tcp: add sanity tests to TCP_QUEUE_SEQ
Qingyu Li reported a syzkaller bug where the repro changes RCV SEQ _after_ restoring data in the receive queue. mprotect(0x4aa000, 12288, PROT_READ) = 0 mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0 setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0 sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20 setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0 setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0 recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer) syslog shows: [ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0 [ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0 This should not be allowed. TCP_QUEUE_SEQ should only be used when queues are empty. This patch fixes this case, and the tx path as well. Fixes: ee9952831cfd ("tcp: Initial repair mode") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=212005 Reported-by: Qingyu Li <ieatmuttonchuan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp.c23
1 files changed, 15 insertions, 8 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index dfb6f286c1de..de7cc8445ac0 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3469,16 +3469,23 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname,
break;
case TCP_QUEUE_SEQ:
- if (sk->sk_state != TCP_CLOSE)
+ if (sk->sk_state != TCP_CLOSE) {
err = -EPERM;
- else if (tp->repair_queue == TCP_SEND_QUEUE)
- WRITE_ONCE(tp->write_seq, val);
- else if (tp->repair_queue == TCP_RECV_QUEUE) {
- WRITE_ONCE(tp->rcv_nxt, val);
- WRITE_ONCE(tp->copied_seq, val);
- }
- else
+ } else if (tp->repair_queue == TCP_SEND_QUEUE) {
+ if (!tcp_rtx_queue_empty(sk))
+ err = -EPERM;
+ else
+ WRITE_ONCE(tp->write_seq, val);
+ } else if (tp->repair_queue == TCP_RECV_QUEUE) {
+ if (tp->rcv_nxt != tp->copied_seq) {
+ err = -EPERM;
+ } else {
+ WRITE_ONCE(tp->rcv_nxt, val);
+ WRITE_ONCE(tp->copied_seq, val);
+ }
+ } else {
err = -EINVAL;
+ }
break;
case TCP_REPAIR_OPTIONS: