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authorLaura Abbott <labbott@redhat.com>2018-09-04 11:47:40 -0700
committerMartin K. Petersen <martin.petersen@oracle.com>2018-09-11 20:47:08 -0400
commit679fcae46c8b2352bba3485d521da070cfbe68e6 (patch)
tree7dd0d16bc5f68c5d459e39089d2dc81a678f2047 /drivers/target/iscsi
parentc77a2fa3ff8f73d1a485e67e6f81c64823739d59 (diff)
scsi: iscsi: target: Don't use stack buffer for scatterlist
Fedora got a bug report of a crash with iSCSI: kernel BUG at include/linux/scatterlist.h:143! ... RIP: 0010:iscsit_do_crypto_hash_buf+0x154/0x180 [iscsi_target_mod] ... Call Trace: ? iscsi_target_tx_thread+0x200/0x200 [iscsi_target_mod] iscsit_get_rx_pdu+0x4cd/0xa90 [iscsi_target_mod] ? native_sched_clock+0x3e/0xa0 ? iscsi_target_tx_thread+0x200/0x200 [iscsi_target_mod] iscsi_target_rx_thread+0x81/0xf0 [iscsi_target_mod] kthread+0x120/0x140 ? kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x3a/0x50 This is a BUG_ON for using a stack buffer with a scatterlist. There are two cases that trigger this bug. Switch to using a dynamically allocated buffer for one case and do not assign a NULL buffer in another case. Signed-off-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/target/iscsi')
-rw-r--r--drivers/target/iscsi/iscsi_target.c22
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 9cdfccbdd06f..cc756a123fd8 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1416,7 +1416,8 @@ static void iscsit_do_crypto_hash_buf(struct ahash_request *hash,
sg_init_table(sg, ARRAY_SIZE(sg));
sg_set_buf(sg, buf, payload_length);
- sg_set_buf(sg + 1, pad_bytes, padding);
+ if (padding)
+ sg_set_buf(sg + 1, pad_bytes, padding);
ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
@@ -3910,10 +3911,14 @@ 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 = kcalloc(ISCSI_HDR_LEN, sizeof(*buffer), GFP_KERNEL);
+ if (!buffer)
+ return;
+
while (!kthread_should_stop()) {
/*
* Ensure that both TX and RX per connection kthreads
@@ -3921,7 +3926,6 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
*/
iscsit_thread_check_cpumask(conn, current, 0);
- memset(buffer, 0, ISCSI_HDR_LEN);
memset(&iov, 0, sizeof(struct kvec));
iov.iov_base = buffer;
@@ -3930,7 +3934,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
if (ret != ISCSI_HDR_LEN) {
iscsit_rx_thread_wait_for_tcp(conn);
- return;
+ break;
}
if (conn->conn_ops->HeaderDigest) {
@@ -3940,7 +3944,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
if (ret != ISCSI_CRC_LEN) {
iscsit_rx_thread_wait_for_tcp(conn);
- return;
+ break;
}
iscsit_do_crypto_hash_buf(conn->conn_rx_hash, buffer,
@@ -3964,7 +3968,7 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
}
if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
- return;
+ break;
opcode = buffer[0] & ISCSI_OPCODE_MASK;
@@ -3975,13 +3979,15 @@ static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
" while in Discovery Session, rejecting.\n", opcode);
iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
buffer);
- return;
+ break;
}
ret = iscsi_target_rx_opcode(conn, buffer);
if (ret < 0)
- return;
+ break;
}
+
+ kfree(buffer);
}
int iscsi_target_rx_thread(void *arg)