diff options
| author | Martin K. Petersen <martin.petersen@oracle.com> | 2017-04-04 10:42:30 -0400 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-04-07 17:07:16 -0400 |
| commit | 7c856152cb92f8eee2df29ef325a1b1f43161aff (patch) | |
| tree | e90a0cc26a6aabfbcb4cc8b064ea6e4575aca206 /drivers/scsi/sd.c | |
| parent | bf6061b17a8d47ef0d9344d3ef576a4ff0edf793 (diff) | |
scsi: sd: Fix capacity calculation with 32-bit sector_t
We previously made sure that the reported disk capacity was less than
0xffffffff blocks when the kernel was not compiled with large sector_t
support (CONFIG_LBDAF). However, this check assumed that the capacity
was reported in units of 512 bytes.
Add a sanity check function to ensure that we only enable disks if the
entire reported capacity can be expressed in terms of sector_t.
Cc: <stable@vger.kernel.org>
Reported-by: Steve Magnani <steve.magnani@digidescorp.com>
Cc: Bart Van Assche <Bart.VanAssche@sandisk.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/sd.c')
| -rw-r--r-- | drivers/scsi/sd.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 906cd6bfa2a9..fe0f7997074e 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2102,6 +2102,22 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp, #define READ_CAPACITY_RETRIES_ON_RESET 10 +/* + * Ensure that we don't overflow sector_t when CONFIG_LBDAF is not set + * and the reported logical block size is bigger than 512 bytes. Note + * that last_sector is a u64 and therefore logical_to_sectors() is not + * applicable. + */ +static bool sd_addressable_capacity(u64 lba, unsigned int sector_size) +{ + u64 last_sector = (lba + 1ULL) << (ilog2(sector_size) - 9); + + if (sizeof(sector_t) == 4 && last_sector > U32_MAX) + return false; + + return true; +} + static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, unsigned char *buffer) { @@ -2167,7 +2183,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, return -ENODEV; } - if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) { + if (!sd_addressable_capacity(lba, sector_size)) { sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a " "kernel compiled with support for large block " "devices.\n"); @@ -2256,7 +2272,7 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp, return sector_size; } - if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) { + if (!sd_addressable_capacity(lba, sector_size)) { sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a " "kernel compiled with support for large block " "devices.\n"); |