From: Jason Gunthorpe jgg@mellanox.com
commit 7c11910783a1ea17e88777552ef146cace607b3c upstream.
The rdma_cm must be used single threaded.
This appears to be a bug in the design, as it does have lots of locking that seems like it should allow concurrency. However, when it is all said and done every single place that uses the cma_exch() scheme is broken, and all the unlocked reads from the ucma of the cm_id data are wrong too.
syzkaller has been finding endless bugs related to this.
Fixing this in any elegant way is some enormous amount of work. Take a very big hammer and put a mutex around everything to do with the ucma_context at the top of every syscall.
Fixes: 75216638572f ("RDMA/cma: Export rdma cm interface to userspace") Link: https://lore.kernel.org/r/20200218210432.GA31966@ziepe.ca Reported-by: syzbot+adb15cf8c2798e4e0db4@syzkaller.appspotmail.com Reported-by: syzbot+e5579222b6a3edd96522@syzkaller.appspotmail.com Reported-by: syzbot+4b628fcc748474003457@syzkaller.appspotmail.com Reported-by: syzbot+29ee8f76017ce6cf03da@syzkaller.appspotmail.com Reported-by: syzbot+6956235342b7317ec564@syzkaller.appspotmail.com Reported-by: syzbot+b358909d8d01556b790b@syzkaller.appspotmail.com Reported-by: syzbot+6b46b135602a3f3ac99e@syzkaller.appspotmail.com Reported-by: syzbot+8458d13b13562abf6b77@syzkaller.appspotmail.com Reported-by: syzbot+bd034f3fdc0402e942ed@syzkaller.appspotmail.com Reported-by: syzbot+c92378b32760a4eef756@syzkaller.appspotmail.com Reported-by: syzbot+68b44a1597636e0b342c@syzkaller.appspotmail.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/core/ucma.c | 49 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 47 insertions(+), 2 deletions(-)
--- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -89,6 +89,7 @@ struct ucma_context {
struct ucma_file *file; struct rdma_cm_id *cm_id; + struct mutex mutex; u64 uid;
struct list_head list; @@ -215,6 +216,7 @@ static struct ucma_context *ucma_alloc_c init_completion(&ctx->comp); INIT_LIST_HEAD(&ctx->mc_list); ctx->file = file; + mutex_init(&ctx->mutex);
mutex_lock(&mut); ctx->id = idr_alloc(&ctx_idr, ctx, 0, 0, GFP_KERNEL); @@ -596,6 +598,7 @@ static int ucma_free_ctx(struct ucma_con }
events_reported = ctx->events_reported; + mutex_destroy(&ctx->mutex); kfree(ctx); return events_reported; } @@ -665,7 +668,10 @@ static ssize_t ucma_bind_ip(struct ucma_ if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); ret = rdma_bind_addr(ctx->cm_id, (struct sockaddr *) &cmd.addr); + mutex_unlock(&ctx->mutex); + ucma_put_ctx(ctx); return ret; } @@ -688,7 +694,9 @@ static ssize_t ucma_bind(struct ucma_fil if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); ret = rdma_bind_addr(ctx->cm_id, (struct sockaddr *) &cmd.addr); + mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; } @@ -712,8 +720,10 @@ static ssize_t ucma_resolve_ip(struct uc if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); ret = rdma_resolve_addr(ctx->cm_id, (struct sockaddr *) &cmd.src_addr, (struct sockaddr *) &cmd.dst_addr, cmd.timeout_ms); + mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; } @@ -738,8 +748,10 @@ static ssize_t ucma_resolve_addr(struct if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); ret = rdma_resolve_addr(ctx->cm_id, (struct sockaddr *) &cmd.src_addr, (struct sockaddr *) &cmd.dst_addr, cmd.timeout_ms); + mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; } @@ -759,7 +771,9 @@ static ssize_t ucma_resolve_route(struct if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); ret = rdma_resolve_route(ctx->cm_id, cmd.timeout_ms); + mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; } @@ -848,6 +862,7 @@ static ssize_t ucma_query_route(struct u if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); memset(&resp, 0, sizeof resp); addr = (struct sockaddr *) &ctx->cm_id->route.addr.src_addr; memcpy(&resp.src_addr, addr, addr->sa_family == AF_INET ? @@ -871,6 +886,7 @@ static ssize_t ucma_query_route(struct u ucma_copy_iw_route(&resp, &ctx->cm_id->route);
out: + mutex_unlock(&ctx->mutex); if (copy_to_user(u64_to_user_ptr(cmd.response), &resp, sizeof(resp))) ret = -EFAULT; @@ -1022,6 +1038,7 @@ static ssize_t ucma_query(struct ucma_fi if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); switch (cmd.option) { case RDMA_USER_CM_QUERY_ADDR: ret = ucma_query_addr(ctx, response, out_len); @@ -1036,6 +1053,7 @@ static ssize_t ucma_query(struct ucma_fi ret = -ENOSYS; break; } + mutex_unlock(&ctx->mutex);
ucma_put_ctx(ctx); return ret; @@ -1076,7 +1094,9 @@ static ssize_t ucma_connect(struct ucma_ return PTR_ERR(ctx);
ucma_copy_conn_param(ctx->cm_id, &conn_param, &cmd.conn_param); + mutex_lock(&ctx->mutex); ret = rdma_connect(ctx->cm_id, &conn_param); + mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; } @@ -1097,7 +1117,9 @@ static ssize_t ucma_listen(struct ucma_f
ctx->backlog = cmd.backlog > 0 && cmd.backlog < max_backlog ? cmd.backlog : max_backlog; + mutex_lock(&ctx->mutex); ret = rdma_listen(ctx->cm_id, ctx->backlog); + mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; } @@ -1120,13 +1142,17 @@ static ssize_t ucma_accept(struct ucma_f if (cmd.conn_param.valid) { ucma_copy_conn_param(ctx->cm_id, &conn_param, &cmd.conn_param); mutex_lock(&file->mut); + mutex_lock(&ctx->mutex); ret = __rdma_accept(ctx->cm_id, &conn_param, NULL); + mutex_unlock(&ctx->mutex); if (!ret) ctx->uid = cmd.uid; mutex_unlock(&file->mut); - } else + } else { + mutex_lock(&ctx->mutex); ret = __rdma_accept(ctx->cm_id, NULL, NULL); - + mutex_unlock(&ctx->mutex); + } ucma_put_ctx(ctx); return ret; } @@ -1145,7 +1171,9 @@ static ssize_t ucma_reject(struct ucma_f if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); ret = rdma_reject(ctx->cm_id, cmd.private_data, cmd.private_data_len); + mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; } @@ -1164,7 +1192,9 @@ static ssize_t ucma_disconnect(struct uc if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); ret = rdma_disconnect(ctx->cm_id); + mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; } @@ -1195,7 +1225,9 @@ static ssize_t ucma_init_qp_attr(struct resp.qp_attr_mask = 0; memset(&qp_attr, 0, sizeof qp_attr); qp_attr.qp_state = cmd.qp_state; + mutex_lock(&ctx->mutex); ret = rdma_init_qp_attr(ctx->cm_id, &qp_attr, &resp.qp_attr_mask); + mutex_unlock(&ctx->mutex); if (ret) goto out;
@@ -1274,9 +1306,13 @@ static int ucma_set_ib_path(struct ucma_ struct sa_path_rec opa;
sa_convert_path_ib_to_opa(&opa, &sa_path); + mutex_lock(&ctx->mutex); ret = rdma_set_ib_path(ctx->cm_id, &opa); + mutex_unlock(&ctx->mutex); } else { + mutex_lock(&ctx->mutex); ret = rdma_set_ib_path(ctx->cm_id, &sa_path); + mutex_unlock(&ctx->mutex); } if (ret) return ret; @@ -1309,7 +1345,9 @@ static int ucma_set_option_level(struct
switch (level) { case RDMA_OPTION_ID: + mutex_lock(&ctx->mutex); ret = ucma_set_option_id(ctx, optname, optval, optlen); + mutex_unlock(&ctx->mutex); break; case RDMA_OPTION_IB: ret = ucma_set_option_ib(ctx, optname, optval, optlen); @@ -1369,8 +1407,10 @@ static ssize_t ucma_notify(struct ucma_f if (IS_ERR(ctx)) return PTR_ERR(ctx);
+ mutex_lock(&ctx->mutex); if (ctx->cm_id->device) ret = rdma_notify(ctx->cm_id, (enum ib_event_type)cmd.event); + mutex_unlock(&ctx->mutex);
ucma_put_ctx(ctx); return ret; @@ -1413,8 +1453,10 @@ static ssize_t ucma_process_join(struct mc->join_state = join_state; mc->uid = cmd->uid; memcpy(&mc->addr, addr, cmd->addr_size); + mutex_lock(&ctx->mutex); ret = rdma_join_multicast(ctx->cm_id, (struct sockaddr *)&mc->addr, join_state, mc); + mutex_unlock(&ctx->mutex); if (ret) goto err2;
@@ -1518,7 +1560,10 @@ static ssize_t ucma_leave_multicast(stru goto out; }
+ mutex_lock(&mc->ctx->mutex); rdma_leave_multicast(mc->ctx->cm_id, (struct sockaddr *) &mc->addr); + mutex_unlock(&mc->ctx->mutex); + mutex_lock(&mc->ctx->file->mut); ucma_cleanup_mc_events(mc); list_del(&mc->list);