[PATCH 5.4 086/215] USB: usb-storage: Prevent divide-by-0 error in isd200_ata_command

Greg Kroah-Hartman
2024-04-11T10:18:14Z

From: Alan Stern <stern@rowland.harvard.edu>

commit 014bcf41d946b36a8f0b8e9b5d9529efbb822f49 upstream.

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 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reviewed-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/b1e605ea-333f-4ac0-9511-da04f411763e@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/storage/isd200.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)

--- a/drivers/usb/storage/isd200.c
+++ b/drivers/usb/storage/isd200.c
@@ -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;
}