4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx> Reported-and-tested-by: syzbot+28748250ab47a8f04100@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://lore.kernel.org/linux-usb/0000000000003eb868061245ba7f@xxxxxxxxxx/ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: PrasannaKumar Muralidharan <prasannatsmkumar@xxxxxxxxx> Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Link: https://lore.kernel.org/r/b1e605ea-333f-4ac0-9511-da04f411763e@xxxxxxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -1104,7 +1104,7 @@ 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"); @@ -1136,6 +1136,13 @@ 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 */ @@ -1201,6 +1208,7 @@ static int isd200_get_inquiry_data( stru } } + Done: usb_stor_dbg(us, "Leaving isd200_get_inquiry_data %08X\n", retStatus); return(retStatus); @@ -1480,22 +1488,27 @@ 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; }
