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-rw-r--r--block/scsi_ioctl.c43
1 files changed, 38 insertions, 5 deletions
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 5f8e798..f0e0ce0 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -32,6 +32,11 @@
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_cmnd.h>
+struct blk_cmd_filter {
+ unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
+ unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
+} blk_default_cmd_filter;
+
/* Command group 3 is reserved and should never be used. */
const unsigned char scsi_command_size_tbl[8] =
{
@@ -105,7 +110,7 @@ static int sg_emulated_host(struct request_queue *q, int __user *p)
return put_user(1, p);
}
-void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
+static void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
{
/* Basic read-only commands */
__set_bit(TEST_UNIT_READY, filter->read_ok);
@@ -187,14 +192,37 @@ void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
__set_bit(GPCMD_SET_STREAMING, filter->write_ok);
__set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
}
-EXPORT_SYMBOL_GPL(blk_set_cmd_filter_defaults);
+
+int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm)
+{
+ struct blk_cmd_filter *filter = &blk_default_cmd_filter;
+
+ /* root can do any command. */
+ if (capable(CAP_SYS_RAWIO))
+ return 0;
+
+ /* if there's no filter set, assume we're filtering everything out */
+ if (!filter)
+ return -EPERM;
+
+ /* Anybody who can open the device can do a read-safe command */
+ if (test_bit(cmd[0], filter->read_ok))
+ return 0;
+
+ /* Write-safe commands require a writable open */
+ if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
+ return 0;
+
+ return -EPERM;
+}
+EXPORT_SYMBOL(blk_verify_command);
static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
struct sg_io_hdr *hdr, fmode_t mode)
{
if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
return -EFAULT;
- if (blk_verify_command(&q->cmd_filter, rq->cmd, mode & FMODE_WRITE))
+ if (blk_verify_command(rq->cmd, mode & FMODE_WRITE))
return -EPERM;
/*
@@ -427,7 +455,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
goto error;
- err = blk_verify_command(&q->cmd_filter, rq->cmd, mode & FMODE_WRITE);
+ err = blk_verify_command(rq->cmd, mode & FMODE_WRITE);
if (err)
goto error;
@@ -645,5 +673,10 @@ int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mod
blk_put_queue(q);
return err;
}
-
EXPORT_SYMBOL(scsi_cmd_ioctl);
+
+int __init blk_scsi_ioctl_init(void)
+{
+ blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
+ return 0;
+}
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