From c75ab8a55ac1083c232e4407f52b0cadae6c1e0e Mon Sep 17 00:00:00 2001
From: shamir rabinovitch <shamir.rabinovitch@oracle.com>
Date: Sun, 16 Dec 2018 09:01:09 +0200
Subject: [PATCH] net/rds: remove user triggered WARN_ON in rds_sendmsg
Git-commit: c75ab8a55ac1083c232e4407f52b0cadae6c1e0e
Patch-mainline: v4.20
References: bsc#1154848
[ Slightly modified for adaping the downstream changes -- tiwai ]
per comment from Leon in rdma mailing list
https://lkml.org/lkml/2018/10/31/312 :
Please don't forget to remove user triggered WARN_ON.
https://lwn.net/Articles/769365/
"Greg Kroah-Hartman raised the problem of core kernel API code that will
use WARN_ON_ONCE() to complain about bad usage; that will not generate
the desired result if WARN_ON_ONCE() is configured to crash the machine.
He was told that the code should just call pr_warn() instead, and that
the called function should return an error in such situations. It was
generally agreed that any WARN_ON() or WARN_ON_ONCE() calls that can be
triggered from user space need to be fixed."
in addition harden rds_sendmsg to detect and overcome issues with
invalid sg count and fail the sendmsg.
Suggested-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: shamir rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/rds/message.c | 24 ++++++++++++++++++------
net/rds/rdma.c | 12 ++++--------
net/rds/rds.h | 3 ++-
net/rds/send.c | 9 +++++----
4 files changed, 29 insertions(+), 19 deletions(-)
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -219,16 +219,27 @@ out:
/*
* RDS ops use this to grab SG entries from the rm's sg pool.
*/
-struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents)
+struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents,
+ int *ret)
{
struct scatterlist *sg_first = (struct scatterlist *) &rm[1];
struct scatterlist *sg_ret;
- WARN_ON(rm->m_used_sgs + nents > rm->m_total_sgs);
- WARN_ON(!nents);
+ if (WARN_ON(!ret))
+ return NULL;
+
+ if (nents <= 0) {
+ pr_warn("rds: alloc sgs failed! nents <= 0\n");
+ *ret = -EINVAL;
+ return NULL;
+ }
- if (rm->m_used_sgs + nents > rm->m_total_sgs)
+ if (rm->m_used_sgs + nents > rm->m_total_sgs) {
+ pr_warn("rds: alloc sgs failed! total %d used %d nents %d\n",
+ rm->m_total_sgs, rm->m_used_sgs, nents);
+ *ret = -ENOMEM;
return NULL;
+ }
sg_ret = &sg_first[rm->m_used_sgs];
sg_init_table(sg_ret, nents);
@@ -243,6 +254,7 @@ struct rds_message *rds_message_map_page
unsigned int i;
int num_sgs = ceil(total_len, PAGE_SIZE);
int extra_bytes = num_sgs * sizeof(struct scatterlist);
+ int ret;
rm = rds_message_alloc(extra_bytes, GFP_NOWAIT);
if (!rm)
@@ -251,10 +263,10 @@ struct rds_message *rds_message_map_page
set_bit(RDS_MSG_PAGEVEC, &rm->m_flags);
rm->m_inc.i_hdr.h_len = cpu_to_be32(total_len);
rm->data.op_nents = ceil(total_len, PAGE_SIZE);
- rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs);
+ rm->data.op_sg = rds_message_alloc_sgs(rm, num_sgs, &ret);
if (!rm->data.op_sg) {
rds_message_put(rm);
- return ERR_PTR(-ENOMEM);
+ return ERR_PTR(ret);
}
for (i = 0; i < rm->data.op_nents; ++i) {
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -621,11 +621,9 @@ int rds_cmsg_rdma_args(struct rds_sock *
op->op_active = 1;
op->op_recverr = rs->rs_recverr;
WARN_ON(!nr_pages);
- op->op_sg = rds_message_alloc_sgs(rm, nr_pages);
- if (!op->op_sg) {
- ret = -ENOMEM;
+ op->op_sg = rds_message_alloc_sgs(rm, nr_pages, &ret);
+ if (!op->op_sg)
goto out_pages;
- }
if (op->op_notify || op->op_recverr) {
/* We allocate an uninitialized notifier here, because
@@ -836,11 +834,9 @@ int rds_cmsg_atomic(struct rds_sock *rs,
rm->atomic.op_silent = !!(args->flags & RDS_RDMA_SILENT);
rm->atomic.op_active = 1;
rm->atomic.op_recverr = rs->rs_recverr;
- rm->atomic.op_sg = rds_message_alloc_sgs(rm, 1);
- if (!rm->atomic.op_sg) {
- ret = -ENOMEM;
+ rm->atomic.op_sg = rds_message_alloc_sgs(rm, 1, &ret);
+ if (!rm->atomic.op_sg)
goto err;
- }
/* verify 8 byte-aligned */
if (args->local_addr & 0x7) {
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -779,7 +779,8 @@ rds_conn_connecting(struct rds_connectio
/* message.c */
struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
-struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents);
+struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents,
+ int *ret);
int rds_message_copy_from_user(struct rds_message *rm, struct iov_iter *from);
struct rds_message *rds_message_map_pages(unsigned long *page_addrs, unsigned int total_len);
void rds_message_populate_header(struct rds_header *hdr, __be16 sport,
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -874,6 +874,9 @@ static int rds_rm_size(struct msghdr *ms
int retval;
struct rds_iov_vector *iov, *tmp_iov;
+ if (data_len < 0)
+ return -EINVAL;
+
for_each_cmsghdr(cmsg, msg) {
if (!CMSG_OK(msg, cmsg))
return -EINVAL;
@@ -1124,11 +1127,9 @@ int rds_sendmsg(struct socket *sock, str
/* Attach data to the rm */
if (payload_len) {
- rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE));
- if (!rm->data.op_sg) {
- ret = -ENOMEM;
+ rm->data.op_sg = rds_message_alloc_sgs(rm, ceil(payload_len, PAGE_SIZE), &ret);
+ if (!rm->data.op_sg)
goto out;
- }
ret = rds_message_copy_from_user(rm, &msg->msg_iter);
if (ret)
goto out;