This is a note to let you know that I've just added the patch titled libata: reject passthrough WRITE SAME requests to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: libata-reject-passthrough-write-same-requests.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From c6ade20f5e50e188d20b711a618b20dd1d50457e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig <hch@xxxxxx> Date: Tue, 25 Apr 2017 13:39:54 +0200 Subject: libata: reject passthrough WRITE SAME requests From: Christoph Hellwig <hch@xxxxxx> commit c6ade20f5e50e188d20b711a618b20dd1d50457e upstream. The WRITE SAME to TRIM translation rewrites the DATA OUT buffer. While the SCSI code accomodates for this by passing a read-writable buffer userspace applications don't cater for this behavior. In fact it can be used to rewrite e.g. a readonly file through mmap and should be considered as a security fix. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/ata/libata-scsi.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -3405,6 +3405,14 @@ static unsigned int ata_scsi_write_same_ if (unlikely(!dev->dma_mode)) goto invalid_opcode; + /* + * We only allow sending this command through the block layer, + * as it modifies the DATA OUT buffer, which would corrupt user + * memory for SG_IO commands. + */ + if (unlikely(blk_rq_is_passthrough(scmd->request))) + goto invalid_opcode; + if (unlikely(scmd->cmd_len < 16)) { fp = 15; goto invalid_fld; Patches currently in stable-queue which might be from hch@xxxxxx are queue-4.9/fs-block_dev-always-invalidate-cleancache-in-invalidate_bdev.patch queue-4.9/target-fileio-fix-zero-length-read-and-write-handling.patch queue-4.9/libata-reject-passthrough-write-same-requests.patch queue-4.9/dm-rq-check-blk_mq_register_dev-return-value-in-dm_mq_init_request_queue.patch