This is a note to let you know that I've just added the patch titled
libata: reject passthrough WRITE SAME requests
to the 4.10-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-4.10 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
@@ -3487,6 +3487,14 @@ 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-4.10/fs-block_dev-always-invalidate-cleancache-in-invalidate_bdev.patch
queue-4.10/target-fileio-fix-zero-length-read-and-write-handling.patch
queue-4.10/libata-reject-passthrough-write-same-requests.patch
queue-4.10/dm-rq-check-blk_mq_register_dev-return-value-in-dm_mq_init_request_queue.patch