===================================================================
@@ -1105,7 +1105,7 @@ static void isd200_dump_driveid(struct u
static int isd200_get_inquiry_data( struct us_data *us )
{
struct isd200_info *info = (struct isd200_info *)us->extra;
- int retStatus = ISD200_GOOD;
+ int retStatus;
u16 *id = info->id;
usb_stor_dbg(us, "Entering isd200_get_inquiry_data\n");
@@ -1137,6 +1137,13 @@ static int isd200_get_inquiry_data( stru
isd200_fix_driveid(id);
isd200_dump_driveid(us, id);
+ /* Prevent division by 0 in isd200_scsi_to_ata() */
+ if (id[ATA_ID_HEADS] == 0 || id[ATA_ID_SECTORS] == 0) {
+ usb_stor_dbg(us, " Invalid ATA Identify data\n");
+ retStatus = ISD200_ERROR;
+ goto Done;
+ }
+
memset(&info->InquiryData, 0, sizeof(info->InquiryData));
/* Standard IDE interface only supports disks */
@@ -1202,6 +1209,7 @@ static int isd200_get_inquiry_data( stru
}
}
+ Done:
usb_stor_dbg(us, "Leaving isd200_get_inquiry_data %08X\n", retStatus);
return(retStatus);
@@ -1481,22 +1489,27 @@ static int isd200_init_info(struct us_da
static int isd200_Initialization(struct us_data *us)
{
+ int rc = 0;
+
usb_stor_dbg(us, "ISD200 Initialization...\n");
/* Initialize ISD200 info struct */
- if (isd200_init_info(us) == ISD200_ERROR) {
+ if (isd200_init_info(us) < 0) {
usb_stor_dbg(us, "ERROR Initializing ISD200 Info struct\n");
+ rc = -ENOMEM;
} else {
/* Get device specific data */
- if (isd200_get_inquiry_data(us) != ISD200_GOOD)
+ if (isd200_get_inquiry_data(us) != ISD200_GOOD) {
usb_stor_dbg(us, "ISD200 Initialization Failure\n");
- else
+ rc = -EINVAL;
+ } else {
usb_stor_dbg(us, "ISD200 Initialization complete\n");
+ }
}
- return 0;
+ return rc;
}
The isd200 sub-driver in usb-storage uses the HEADS and SECTORS values in the ATA ID information to calculate cylinder and head values when creating a CDB for READ or WRITE commands. The calculation involves division and modulus operations, which will cause a crash if either of these values is 0. While this never happens with a genuine device, it could happen with a flawed or subversive emulation, as reported by the syzbot fuzzer. Protect against this possibility by refusing to bind to the device if either the ATA_ID_HEADS or ATA_ID_SECTORS value in the device's ID information is 0. This requires isd200_Initialization() to return a negative error code when initialization fails; currently it always returns 0 (even when there is an error). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: syzbot+28748250ab47a8f04100@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-usb/0000000000003eb868061245ba7f@google.com/ Fixes: 1da177e4c3f4 ("v2.6.12-rc2") Cc: <stable@vger.kernel.org> --- drivers/usb/storage/isd200.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-)