diff options
Diffstat (limited to 'block/scsi_ioctl.c')
| -rw-r--r-- | block/scsi_ioctl.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index c2ac36dfe4f3..cc72210687eb 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -21,6 +21,7 @@ #include <linux/string.h> #include <linux/module.h> #include <linux/blkdev.h> +#include <linux/capability.h> #include <linux/completion.h> #include <linux/cdrom.h> #include <linux/slab.h> @@ -190,16 +191,21 @@ static int verify_command(struct file *file, unsigned char *cmd) safe_for_write(GPCMD_SET_STREAMING), }; unsigned char type = cmd_type[cmd[0]]; + int has_write_perm = 0; /* Anybody who can open the device can do a read-safe command */ if (type & CMD_READ_SAFE) return 0; + /* + * file can be NULL from ioctl_by_bdev()... + */ + if (file) + has_write_perm = file->f_mode & FMODE_WRITE; + /* Write-safe commands just require a writable open.. */ - if (type & CMD_WRITE_SAFE) { - if (file->f_mode & FMODE_WRITE) - return 0; - } + if ((type & CMD_WRITE_SAFE) && has_write_perm) + return 0; /* And root can do any command.. */ if (capable(CAP_SYS_RAWIO)) |