From 3427beb6375d04e9627c67343872e79341a684ea Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 2 Jul 2019 15:55:28 +0100 Subject: rxrpc: Fix uninitialized error code in rxrpc_send_data_packet() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With gcc 4.1: net/rxrpc/output.c: In function ‘rxrpc_send_data_packet’: net/rxrpc/output.c:338: warning: ‘ret’ may be used uninitialized in this function Indeed, if the first jump to the send_fragmentable label is made, and the address family is not handled in the switch() statement, ret will be used uninitialized. Fix this by BUG()'ing as is done in other places in rxrpc where internal support for future address families will need adding. It should not be possible to reach this normally as the address families are checked up-front. Fixes: 5a924b8951f835b5 ("rxrpc: Don't store the rxrpc header in the Tx queue sk_buffs") Reported-by: Geert Uytterhoeven Signed-off-by: David Howells Signed-off-by: David S. Miller --- net/rxrpc/output.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net/rxrpc') diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index a0b6abfbd277..948e3fe249ec 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -519,6 +519,9 @@ send_fragmentable: } break; #endif + + default: + BUG(); } if (ret < 0) -- cgit v1.2.3 From e835ada07091f40dcfb1bc735082bd0a7c005e59 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 2 Jul 2019 15:59:12 +0100 Subject: rxrpc: Fix send on a connected, but unbound socket If sendmsg() or sendmmsg() is called on a connected socket that hasn't had bind() called on it, then an oops will occur when the kernel tries to connect the call because no local endpoint has been allocated. Fix this by implicitly binding the socket if it is in the RXRPC_CLIENT_UNBOUND state, just like it does for the RXRPC_UNBOUND state. Further, the state should be transitioned to RXRPC_CLIENT_BOUND after this to prevent further attempts to bind it. This can be tested with: #include #include #include #include #include #include static const unsigned char inet6_addr[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, -1, 0xac, 0x14, 0x14, 0xaa }; int main(void) { struct sockaddr_rxrpc srx; struct cmsghdr *cm; struct msghdr msg; unsigned char control[16]; int fd; memset(&srx, 0, sizeof(srx)); srx.srx_family = 0x21; srx.srx_service = 0; srx.transport_type = AF_INET; srx.transport_len = 0x1c; srx.transport.sin6.sin6_family = AF_INET6; srx.transport.sin6.sin6_port = htons(0x4e22); srx.transport.sin6.sin6_flowinfo = htons(0x4e22); srx.transport.sin6.sin6_scope_id = htons(0xaa3b); memcpy(&srx.transport.sin6.sin6_addr, inet6_addr, 16); cm = (struct cmsghdr *)control; cm->cmsg_len = CMSG_LEN(sizeof(unsigned long)); cm->cmsg_level = SOL_RXRPC; cm->cmsg_type = RXRPC_USER_CALL_ID; *(unsigned long *)CMSG_DATA(cm) = 0; msg.msg_name = NULL; msg.msg_namelen = 0; msg.msg_iov = NULL; msg.msg_iovlen = 0; msg.msg_control = control; msg.msg_controllen = cm->cmsg_len; msg.msg_flags = 0; fd = socket(AF_RXRPC, SOCK_DGRAM, AF_INET); connect(fd, (struct sockaddr *)&srx, sizeof(srx)); sendmsg(fd, &msg, 0); return 0; } Leading to the following oops: BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page ... RIP: 0010:rxrpc_connect_call+0x42/0xa01 ... Call Trace: ? mark_held_locks+0x47/0x59 ? __local_bh_enable_ip+0xb6/0xba rxrpc_new_client_call+0x3b1/0x762 ? rxrpc_do_sendmsg+0x3c0/0x92e rxrpc_do_sendmsg+0x3c0/0x92e rxrpc_sendmsg+0x16b/0x1b5 sock_sendmsg+0x2d/0x39 ___sys_sendmsg+0x1a4/0x22a ? release_sock+0x19/0x9e ? reacquire_held_locks+0x136/0x160 ? release_sock+0x19/0x9e ? find_held_lock+0x2b/0x6e ? __lock_acquire+0x268/0xf73 ? rxrpc_connect+0xdd/0xe4 ? __local_bh_enable_ip+0xb6/0xba __sys_sendmsg+0x5e/0x94 do_syscall_64+0x7d/0x1bf entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: 2341e0775747 ("rxrpc: Simplify connect() implementation and simplify sendmsg() op") Reported-by: syzbot+7966f2a0b2c7da8939b4@syzkaller.appspotmail.com Signed-off-by: David Howells Reviewed-by: Marc Dionne Signed-off-by: David S. Miller --- net/rxrpc/af_rxrpc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/rxrpc') diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index f9f4721cdfa7..d09eaf153544 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -545,6 +545,7 @@ static int rxrpc_sendmsg(struct socket *sock, struct msghdr *m, size_t len) switch (rx->sk.sk_state) { case RXRPC_UNBOUND: + case RXRPC_CLIENT_UNBOUND: rx->srx.srx_family = AF_RXRPC; rx->srx.srx_service = 0; rx->srx.transport_type = SOCK_DGRAM; @@ -569,10 +570,9 @@ static int rxrpc_sendmsg(struct socket *sock, struct msghdr *m, size_t len) } rx->local = local; - rx->sk.sk_state = RXRPC_CLIENT_UNBOUND; + rx->sk.sk_state = RXRPC_CLIENT_BOUND; /* Fall through */ - case RXRPC_CLIENT_UNBOUND: case RXRPC_CLIENT_BOUND: if (!m->msg_name && test_bit(RXRPC_SOCK_CONNECTED, &rx->flags)) { -- cgit v1.2.3