netdev - [PATCH] KS8851: NULL pointer dereference if list is empty

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 16 Apr 2010 19:48:43 -0500
From:	Abraham Arce <abraham.arce.moreno@...il.com>
To:	netdev@...r.kernel.org
Subject: [PATCH] KS8851: NULL pointer dereference if list is empty

Fix NULL pointer dereference in ks8851_tx_work by checking if dequeued
list is already empty before writing the packet to TX FIFO

 Unable to handle kernel NULL pointer dereference at virtual address 00000050
 PC is at ks8851_tx_work+0xdc/0x1b0
 LR is at wait_for_common+0x148/0x164
 pc : [<c01c0df4>]    lr : [<c025a980>]    psr: 20000013
 Backtrace:
  ks8851_tx_work+0x0/0x1b0
  worker_thread+0x0/0x190
  kthread+0x0/0x90

Signed-off-by: Abraham Arce <x0066660@...com>
---
 drivers/net/ks8851.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ks8851.c b/drivers/net/ks8851.c
index 13cc1ca..9e9f9b3 100644
--- a/drivers/net/ks8851.c
+++ b/drivers/net/ks8851.c
@@ -722,12 +722,14 @@ static void ks8851_tx_work(struct work_struct *work)
 		txb = skb_dequeue(&ks->txq);
 		last = skb_queue_empty(&ks->txq);

-		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA);
-		ks8851_wrpkt(ks, txb, last);
-		ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr);
-		ks8851_wrreg16(ks, KS_TXQCR, TXQCR_METFE);
+		if (txb != NULL) {
+			ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA);
+			ks8851_wrpkt(ks, txb, last);
+			ks8851_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr);
+			ks8851_wrreg16(ks, KS_TXQCR, TXQCR_METFE);

-		ks8851_done_tx(ks, txb);
+			ks8851_done_tx(ks, txb);
+		}
 	}

 	mutex_unlock(&ks->lock);
-- 
1.5.4.3
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html