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scsi: sd: Fix capacity calculation with 32-bit sector_t

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commit 7c856152cb92f8eee2df29ef325a1b1f43161aff upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Martin K. Petersen 2017-04-04 10:42:30 -04:00 • committed by Greg Kroah-Hartman
parent 4489619555
commit b689dfbed8
1 changed files with 18 additions and 2 deletions
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20
drivers/scsi/sd.c
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@ -2051,6 +2051,22 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
#define READ_CAPACITY_RETRIES_ON_RESET 10 #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, static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
unsigned char *buffer) unsigned char *buffer)
{ {
@ -2116,7 +2132,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
return -ENODEV; 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 " sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
"kernel compiled with support for large block " "kernel compiled with support for large block "
"devices.\n"); "devices.\n");
@ -2202,7 +2218,7 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
return sector_size; 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 " sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a "
"kernel compiled with support for large block " "kernel compiled with support for large block "
"devices.\n"); "devices.\n");