Messages in this thread Patch in this message | | | From | Colin King <> | Subject | [PATCH][V2] usb: storage: return on error to avoid a null pointer dereference | Date | Thu, 6 Jul 2017 16:06:32 +0100 |
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From: Colin Ian King <colin.king@canonical.com>
When us->extra is null the driver is not initialized, however, a later call to osd200_scsi_to_ata is made that dereferences us->extra, causing a null pointer dereference. The code currently detects and reports that the driver is not initialized; add a return to avoid the subsequent dereference issue in this check.
Thanks to Alan Stern for pointing out that srb->result needs setting to DID_ERROR << 16
Detected by CoverityScan, CID#100308 ("Dereference after null check")
Signed-off-by: Colin Ian King <colin.king@canonical.com> --- drivers/usb/storage/isd200.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/storage/isd200.c b/drivers/usb/storage/isd200.c index fba4005dd737..6a7720e66595 100644 --- a/drivers/usb/storage/isd200.c +++ b/drivers/usb/storage/isd200.c @@ -1529,8 +1529,11 @@ static void isd200_ata_command(struct scsi_cmnd *srb, struct us_data *us) /* Make sure driver was initialized */ - if (us->extra == NULL) + if (us->extra == NULL) { usb_stor_dbg(us, "ERROR Driver not initialized\n"); + srb->result = DID_ERROR << 16; + return; + } scsi_set_resid(srb, 0); /* scsi_bufflen might change in protocol translation to ata */ -- 2.11.0
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