s390/dasd: enforce dma_alignment to ensure proper buffer validation

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commit 130e6de621 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: 2a07bb64d8 ("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>

...

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Jaehoon Kim 2025-09-25 17:47:08 +02:00 • committed by Greg Kroah-Hartman

parent 0a50182e6a

commit 4e6f98bf23

1 changed files with 5 additions and 0 deletions

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drivers/s390/block/dasd.c

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