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authorPaolo Bonzini <pbonzini@redhat.com>2012-09-07 19:30:39 +0400
committerNicholas Bellinger <nab@linux-iscsi.org>2012-09-18 04:13:37 +0400
commit7a3f369ce31694017996524a1cdb08208a839077 (patch)
tree0c191ecc298ae9cf3d0f29a446f6c43e9b9e630c /drivers/target
parentffe7b0e9326d9c68f5688bef691dd49f1e0d3651 (diff)
downloadlinux-7a3f369ce31694017996524a1cdb08208a839077.tar.xz
target: fix truncation of mode data, support zero allocation length
The offset was not bumped back to the full size after writing the header of the MODE SENSE response, so the last 1 or 2 bytes were not copied. On top of this, support zero-length requests by checking for the return value of transport_kmap_data_sg. Testcase: sg_raw -r20 /dev/sdb 5a 00 0a 00 00 00 00 00 14 00 last byte should be 0x1e it is 0x00 without the patch it is correct with the patch Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_spc.c17
1 files changed, 7 insertions, 10 deletions
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index b3d8fd260374..9229bd9ad61b 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -784,7 +784,7 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
unsigned char *rbuf;
int type = dev->transport->get_device_type(dev);
int ten = (cmd->t_task_cdb[0] == MODE_SENSE_10);
- int offset = ten ? 8 : 4;
+ u32 offset = ten ? 8 : 4;
int length = 0;
unsigned char buf[SE_MODE_PAGE_BUF];
@@ -817,6 +817,7 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
offset -= 2;
buf[0] = (offset >> 8) & 0xff;
buf[1] = offset & 0xff;
+ offset += 2;
if ((cmd->se_lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) ||
(cmd->se_deve &&
@@ -826,13 +827,10 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
if ((dev->se_sub_dev->se_dev_attrib.emulate_write_cache > 0) &&
(dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0))
spc_modesense_dpofua(&buf[3], type);
-
- if ((offset + 2) > cmd->data_length)
- offset = cmd->data_length;
-
} else {
offset -= 1;
buf[0] = offset & 0xff;
+ offset += 1;
if ((cmd->se_lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) ||
(cmd->se_deve &&
@@ -842,14 +840,13 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
if ((dev->se_sub_dev->se_dev_attrib.emulate_write_cache > 0) &&
(dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0))
spc_modesense_dpofua(&buf[2], type);
-
- if ((offset + 1) > cmd->data_length)
- offset = cmd->data_length;
}
rbuf = transport_kmap_data_sg(cmd);
- memcpy(rbuf, buf, offset);
- transport_kunmap_data_sg(cmd);
+ if (rbuf) {
+ memcpy(rbuf, buf, min(offset, cmd->data_length));
+ transport_kunmap_data_sg(cmd);
+ }
target_complete_cmd(cmd, GOOD);
return 0;