5.4-stable review patch. If anyone has any objections, please let me know.
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From: Mike Christie michael.christie@oracle.com
commit ccd3f449052449a917a3e577d8ba0368f43b8f29 upstream.
In newer version of the SBC specs, we have a NDOB bit that indicates there is no data buffer that gets written out. If this bit is set using commands like "sg_write_same --ndob" we will crash in target_core_iblock/file's execute_write_same handlers when we go to access the se_cmd->t_data_sg because its NULL.
This patch adds a check for the NDOB bit in the common WRITE SAME code because we don't support it. And, it adds a check for zero SG elements in each handler in case the initiator tries to send a normal WRITE SAME with no data buffer.
Link: https://lore.kernel.org/r/20220628022325.14627-2-michael.christie@oracle.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Mike Christie michael.christie@oracle.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/target/target_core_file.c | 3 +++ drivers/target/target_core_iblock.c | 4 ++++ drivers/target/target_core_sbc.c | 6 ++++++ 3 files changed, 13 insertions(+)
--- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -455,6 +455,9 @@ fd_execute_write_same(struct se_cmd *cmd return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; }
+ if (!cmd->t_data_nents) + return TCM_INVALID_CDB_FIELD; + if (cmd->t_data_nents > 1 || cmd->t_data_sg[0].length != cmd->se_dev->dev_attrib.block_size) { pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" --- a/drivers/target/target_core_iblock.c +++ b/drivers/target/target_core_iblock.c @@ -458,6 +458,10 @@ iblock_execute_write_same(struct se_cmd " backends not supported\n"); return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; } + + if (!cmd->t_data_nents) + return TCM_INVALID_CDB_FIELD; + sg = &cmd->t_data_sg[0];
if (cmd->t_data_nents > 1 || --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -312,6 +312,12 @@ sbc_setup_write_same(struct se_cmd *cmd, pr_warn("WRITE SAME with ANCHOR not supported\n"); return TCM_INVALID_CDB_FIELD; } + + if (flags & 0x01) { + pr_warn("WRITE SAME with NDOB not supported\n"); + return TCM_INVALID_CDB_FIELD; + } + /* * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting * translated into block discard requests within backend code.