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| author | Christoph Hellwig <hch@lst.de> | 2017-04-25 13:39:54 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2017-04-29 00:08:21 +0200 |
| commit | c6ade20f5e50e188d20b711a618b20dd1d50457e (patch) | |
| tree | a6b882286df26b634acaf06a4a27639287b92fee | |
| parent | dt-bindings: ata: add DT bindings for ahci-dm816 SATA controller (diff) | |
| download | linux-c6ade20f5e50e188d20b711a618b20dd1d50457e.tar.xz linux-c6ade20f5e50e188d20b711a618b20dd1d50457e.zip | |
libata: reject passthrough WRITE SAME requests
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@lst.de>
Cc: stable@vger.kernel.org
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | drivers/ata/libata-scsi.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 1ac70744ae7b..50f56d066936 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -3462,6 +3462,14 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc) 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; |