From 42228fa0804a3a01612e855e8b123bae1a06a1e3 Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Wed, 7 Mar 2018 14:49:09 +0200 Subject: [PATCH] RDMA/ucma: Limit possible option size commit 6a21dfc0d0db7b7e0acedce67ca533a6eb19283c upstream. Users of ucma are supposed to provide size of option level, in most paths it is supposed to be equal to u8 or u16, but it is not the case for the IB path record, where it can be multiple of struct ib_path_rec_data. This patch takes simplest possible approach and prevents providing values more than possible to allocate. Reported-by: syzbot+a38b0e9f694c379ca7ce@syzkaller.appspotmail.com Fixes: 7ce86409adcd ("RDMA/ucma: Allow user space to set service type") Signed-off-by: Leon Romanovsky Signed-off-by: Doug Ledford Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/ucma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index 886f61ea6cc7d..62c2c13072ad0 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -1274,6 +1274,9 @@ static ssize_t ucma_set_option(struct ucma_file *file, const char __user *inbuf, if (IS_ERR(ctx)) return PTR_ERR(ctx); + if (unlikely(cmd.optval > KMALLOC_MAX_SIZE)) + return -EINVAL; + optval = memdup_user((void __user *) (unsigned long) cmd.optval, cmd.optlen); if (IS_ERR(optval)) { -- 2.47.2