From: Colin Ian King Date: Thu, 6 Jul 2017 15:06:32 +0000 (+0100) Subject: usb: storage: return on error to avoid a null pointer dereference X-Git-Tag: v4.4.79~48 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ab8e00991809b2c5953fa49c967df14532542183;p=thirdparty%2Fkernel%2Fstable.git usb: storage: return on error to avoid a null pointer dereference commit 446230f52a5bef593554510302465eabab45a372 upstream. 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 Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/storage/isd200.c b/drivers/usb/storage/isd200.c index 39afd7045c43d..7bb5f8da53573 100644 --- a/drivers/usb/storage/isd200.c +++ b/drivers/usb/storage/isd200.c @@ -1520,8 +1520,11 @@ 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 */