6.12-stable review patch. If anyone has any objections, please let me know.
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From: Jaehoon Kim jhkim@linux.ibm.com
commit 130e6de62107116eba124647116276266be0f84c upstream.
The block layer validates buffer alignment using the device's dma_alignment value. If dma_alignment is smaller than logical_block_size(bp_block) -1, misaligned buffer incorrectly pass validation and propagate to the lower-level driver.
This patch adjusts dma_alignment to be at least logical_block_size -1, ensuring that misalignment buffers are properly rejected at the block layer and do not reach the DASD driver unnecessarily.
Fixes: 2a07bb64d801 ("s390/dasd: Remove DMA alignment") Reviewed-by: Stefan Haberland sth@linux.ibm.com Cc: stable@vger.kernel.org #6.11+ Signed-off-by: Jaehoon Kim jhkim@linux.ibm.com Signed-off-by: Stefan Haberland sth@linux.ibm.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/s390/block/dasd.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -332,6 +332,11 @@ static int dasd_state_basic_to_ready(str lim.max_dev_sectors = device->discipline->max_sectors(block); lim.max_hw_sectors = lim.max_dev_sectors; lim.logical_block_size = block->bp_block; + /* + * Adjust dma_alignment to match block_size - 1 + * to ensure proper buffer alignment checks in the block layer. + */ + lim.dma_alignment = lim.logical_block_size - 1;
if (device->discipline->has_discard) { unsigned int max_bytes;