When HeaderDigest is enabled on aarch64 machines, target triggers
a lot of failed crc checksum errors:
example of output in dmesg:
[ 154.495031] HeaderDigest CRC32C failed, received 0x60571c8d, computed
0x288c3ab9
[ 154.583821] Got unknown iSCSI OpCode: 0xff
[ 162.979857] HeaderDigest CRC32C failed, received 0x0712e57c, computed
0x288c3ab9
...
The problem is that the iscsit_get_rx_pdu() function uses
a stack buffer as input for the scatterlist crypto library.
This should be avoided on kernels >= 4.9 because stack buffers
may not be directly mappable to struct page when the
CONFIG_VMAP_STACK option is enabled.
This patch modifies the code so the buffer will be allocated on the heap
and adds a pointer to it in the iscsi_conn structure.
v2: allocate conn_rx_buf in iscsi_target_login_thread()
and fix a memory leak
Signed-off-by: Maurizio Lombardi <mlomb...@redhat.com>
---
drivers/target/iscsi/iscsi_target.c | 6 +++++-
drivers/target/iscsi/iscsi_target_login.c | 15 +++++++++++++++
include/target/iscsi/iscsi_target_core.h | 2 ++
3 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/drivers/target/iscsi/iscsi_target.c
b/drivers/target/iscsi/iscsi_target.c
index 8e22379..149fa91 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -3913,10 +3913,12 @@ static bool iscsi_target_check_conn_state(struct
iscsi_conn *conn)
static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
{
int ret;
- u8 buffer[ISCSI_HDR_LEN], opcode;
+ u8 *buffer, opcode;
u32 checksum = 0, digest = 0;
struct kvec iov;
+ buffer = conn->conn_rx_buf;
+
while (!kthread_should_stop()) {
/*
* Ensure that both TX and RX per connection kthreads
@@ -4211,6 +4213,8 @@ int iscsit_close_connection(
crypto_free_ahash(tfm);
}
+ kfree(conn->conn_rx_buf);
+
free_cpumask_var(conn->conn_cpumask);
kfree(conn->conn_ops);
diff --git a/drivers/target/iscsi/iscsi_target_login.c
b/drivers/target/iscsi/iscsi_target_login.c
index 9950178..4e8974a5 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -1203,6 +1203,8 @@ void iscsi_target_login_sess_out(struct iscsi_conn *conn,
crypto_free_ahash(tfm);
}
+ kfree(conn->conn_rx_buf);
+
free_cpumask_var(conn->conn_cpumask);
kfree(conn->conn_ops);
@@ -1262,6 +1264,15 @@ static int __iscsi_target_login_thread(struct iscsi_np
*np)
/* Get another socket */
return 1;
}
+
+ /* Allocate buffer for iscsit_get_rx_pdu() */
+ conn->conn_rx_buf = kmalloc(ISCSI_HDR_LEN, GFP_KERNEL);
+ if (!conn->conn_rx_buf) {
+ pr_err("Could not allocate memory for conn_rx_buf\n");
+ kfree(conn);
+ return 1;
+ }
+
pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
conn->conn_state = TARG_CONN_STATE_FREE;
@@ -1270,6 +1281,7 @@ static int __iscsi_target_login_thread(struct iscsi_np
*np)
timer_setup(&conn->nopin_timer, iscsit_handle_nopin_timeout, 0);
if (iscsit_conn_set_transport(conn, np->np_transport) < 0) {
+ kfree(conn->conn_rx_buf);
kfree(conn);
return 1;
}
@@ -1278,6 +1290,7 @@ static int __iscsi_target_login_thread(struct iscsi_np
*np)
if (rc == -ENOSYS) {
complete(&np->np_restart_comp);
iscsit_put_transport(conn->conn_transport);
+ kfree(conn->conn_rx_buf);
kfree(conn);
conn = NULL;
goto exit;
@@ -1288,6 +1301,7 @@ static int __iscsi_target_login_thread(struct iscsi_np
*np)
spin_unlock_bh(&np->np_thread_lock);
complete(&np->np_restart_comp);
iscsit_put_transport(conn->conn_transport);
+ kfree(conn->conn_rx_buf);
kfree(conn);
conn = NULL;
/* Get another socket */
@@ -1295,6 +1309,7 @@ static int __iscsi_target_login_thread(struct iscsi_np
*np)
}
spin_unlock_bh(&np->np_thread_lock);
iscsit_put_transport(conn->conn_transport);
+ kfree(conn->conn_rx_buf);
kfree(conn);
conn = NULL;
goto out;
diff --git a/include/target/iscsi/iscsi_target_core.h
b/include/target/iscsi/iscsi_target_core.h
index cf5f3ff..3e9c525 100644
--- a/include/target/iscsi/iscsi_target_core.h
+++ b/include/target/iscsi/iscsi_target_core.h
@@ -584,6 +584,8 @@ struct iscsi_conn {
/* libcrypto RX and TX contexts for crc32c */
struct ahash_request *conn_rx_hash;
struct ahash_request *conn_tx_hash;
+ /* Used as buffer for iscsit_get_rx_pdu */
+ u8 *conn_rx_buf;
/* Used for scheduling TX and RX connection kthreads */
cpumask_var_t conn_cpumask;
unsigned int conn_rx_reset_cpumask:1;
--
1.8.3.1
