Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1696568 > unrolled thread

[PATCH 3.18 27/60] usb: storage: return on error to avoid a null pointer dereference

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH 3.18 27/60] usb: storage: return on error to avoid a null pointer dereference Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-07-25 23:40 +0200

#1696568 — [PATCH 3.18 27/60] usb: storage: return on error to avoid a null pointer dereference

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Colin Ian King <colin.king@canonical.com>

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 <colin.king@canonical.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/storage/isd200.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/usb/storage/isd200.c
+++ b/drivers/usb/storage/isd200.c
@@ -1522,8 +1522,11 @@ static void isd200_ata_command(struct sc
 
 	/* 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 */

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web