From: Nicholas Bellinger nab@linux-iscsi.org
commit 984a9d4c40bed351a92ed31f0723a710444295da upstream.
This reverts commit 0e2eb7d12eaa8e391bf5615d4271bb87a649caaa
Author: Bart Van Assche bart.vanassche@sandisk.com Date: Thu Mar 30 10:12:39 2017 -0700
target: Fix VERIFY and WRITE VERIFY command parsing
This patch broke existing behaviour for WRITE_VERIFY because it dropped the original SCF_SCSI_DATA_CDB assignment for bytchk = 0 so target_cmd_size_check() no longer rejected this case, allowing an overflow case to trigger an OOPs in iscsi-target.
Since the short term and long term fixes are still being discussed, revert it for now since it's late in the merge window and try again in v4.13-rc1.
drivers/target/target_core_sbc.c
Signed-off-by: Nicholas Bellinger nab@linux-iscsi.org --- drivers/target/target_core_sbc.c | 71 +++++----------------------------------- 1 file changed, 9 insertions(+), 62 deletions(-)
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index 8bf7a06..5de51c5 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -768,59 +768,6 @@ sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb) return 0; }
-/** - * sbc_parse_verify - parse VERIFY, VERIFY_16 and WRITE VERIFY commands - * @cmd: (in) structure that describes the SCSI command to be parsed. - * @sectors: (out) Number of logical blocks on the storage medium that will be - * affected by the SCSI command. - * @bufflen: (out) Expected length of the SCSI Data-Out buffer. - */ -static sense_reason_t sbc_parse_verify(struct se_cmd *cmd, int *sectors, - u32 *bufflen) -{ - struct se_device *dev = cmd->se_dev; - u8 *cdb = cmd->t_task_cdb; - u8 bytchk = (cdb[1] >> 1) & 3; - sense_reason_t ret; - - switch (cdb[0]) { - case VERIFY: - case WRITE_VERIFY: - *sectors = transport_get_sectors_10(cdb); - cmd->t_task_lba = transport_lba_32(cdb); - break; - case VERIFY_16: - *sectors = transport_get_sectors_16(cdb); - cmd->t_task_lba = transport_lba_64(cdb); - break; - default: - WARN_ON_ONCE(true); - return TCM_UNSUPPORTED_SCSI_OPCODE; - } - - if (sbc_check_dpofua(dev, cmd, cdb)) - return TCM_INVALID_CDB_FIELD; - - ret = sbc_check_prot(dev, cmd, cdb, *sectors, true); - if (ret) - return ret; - - switch (bytchk) { - case 0: - *bufflen = 0; - break; - case 1: - *bufflen = sbc_get_size(cmd, *sectors); - cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; - break; - default: - pr_err("Unsupported BYTCHK value %d for SCSI opcode %#x\n", - bytchk, cdb[0]); - return TCM_INVALID_CDB_FIELD; - } - return TCM_NO_SENSE; -} - sense_reason_t sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) { @@ -891,6 +838,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) cmd->execute_cmd = sbc_execute_rw; break; case WRITE_10: + case WRITE_VERIFY: sectors = transport_get_sectors_10(cdb); cmd->t_task_lba = transport_lba_32(cdb);
@@ -905,12 +853,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) cmd->execute_rw = ops->execute_rw; cmd->execute_cmd = sbc_execute_rw; break; - case WRITE_VERIFY: - ret = sbc_parse_verify(cmd, §ors, &size); - if (ret) - return ret; - cmd->execute_cmd = sbc_execute_rw; - goto check_lba; case WRITE_12: sectors = transport_get_sectors_12(cdb); cmd->t_task_lba = transport_lba_32(cdb); @@ -1110,9 +1052,14 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) break; case VERIFY: case VERIFY_16: - ret = sbc_parse_verify(cmd, §ors, &size); - if (ret) - return ret; + size = 0; + if (cdb[0] == VERIFY) { + sectors = transport_get_sectors_10(cdb); + cmd->t_task_lba = transport_lba_32(cdb); + } else { + sectors = transport_get_sectors_16(cdb); + cmd->t_task_lba = transport_lba_64(cdb); + } cmd->execute_cmd = sbc_emulate_noop; goto check_lba; case REZERO_UNIT: