On 08/03/2018 03:48 AM, Maurizio Lombardi wrote: > 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 <[email protected]> > --- > 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;
If the buffer is only used in the loop below why does it need to be allocated in __iscsi_target_login_thread? It just seems like the error handling and freeing of that buffer would be more simple if done here.
