From 4f7f4dcfff2c19debbcdbcc861c325610a15e0c5 Mon Sep 17 00:00:00 2001 From: Vlad Tsyrklevich Date: Fri, 24 Mar 2017 15:55:17 -0400 Subject: [PATCH] infiniband/uverbs: Fix integer overflows The 'num_sge' variable is verfied to be smaller than the 'sge_count' variable; however, since both are user-controlled it's possible to cause an integer overflow for the kmalloc multiply on 32-bit platforms (num_sge and sge_count are both defined u32). By crafting an input that causes a smaller-than-expected allocation it's possible to write controlled data out-of-bounds. Signed-off-by: Vlad Tsyrklevich Signed-off-by: Doug Ledford --- drivers/infiniband/core/uverbs_cmd.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 562184ed23c2..7a4a10ef8b49 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -2104,9 +2104,13 @@ ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file, static void *alloc_wr(size_t wr_size, __u32 num_sge) { + if (num_sge >= (U32_MAX - ALIGN(wr_size, sizeof (struct ib_sge))) / + sizeof (struct ib_sge)) + return NULL; + return kmalloc(ALIGN(wr_size, sizeof (struct ib_sge)) + num_sge * sizeof (struct ib_sge), GFP_KERNEL); -}; +} ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file, struct ib_device *ib_dev, @@ -2334,6 +2338,13 @@ static struct ib_recv_wr *ib_uverbs_unmarshall_recv(const char __user *buf, goto err; } + if (user_wr->num_sge >= + (U32_MAX - ALIGN(sizeof *next, sizeof (struct ib_sge))) / + sizeof (struct ib_sge)) { + ret = -EINVAL; + goto err; + } + next = kmalloc(ALIGN(sizeof *next, sizeof (struct ib_sge)) + user_wr->num_sge * sizeof (struct ib_sge), GFP_KERNEL); -- 2.30.2