[PATCH] mISDN: prevent possible NULL pointer dereference

From	Anton Protopopov <a.s.protopopov@gmail.com>
Newsgroups	linux.kernel
Subject	[PATCH] mISDN: prevent possible NULL pointer dereference
Date	2016-02-17 17:30 +0100
Message-ID	<r3d9j-uB-73@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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A return value of the bchannel_get_rxbuf() function is compared with the
positive ENOMEM value instead of the negative -ENOMEM value to detect a
memory allocation problem. Thus, after a possible memory allocation
failure the bc->bch.rx_skb will be NULL which will lead to a NULL
pointer dereference.

Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
---
 drivers/isdn/hardware/mISDN/netjet.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/isdn/hardware/mISDN/netjet.c b/drivers/isdn/hardware/mISDN/netjet.c
index 8e29447..afde4ed 100644
--- a/drivers/isdn/hardware/mISDN/netjet.c
+++ b/drivers/isdn/hardware/mISDN/netjet.c
@@ -392,7 +392,7 @@ read_dma(struct tiger_ch *bc, u32 idx, int cnt)
 	}
 	stat = bchannel_get_rxbuf(&bc->bch, cnt);
 	/* only transparent use the count here, HDLC overun is detected later */
-	if (stat == ENOMEM) {
+	if (stat == -ENOMEM) {
 		pr_warning("%s.B%d: No memory for %d bytes\n",
 			   card->name, bc->bch.nr, cnt);
 		return;
-- 
2.6.5

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[PATCH] mISDN: prevent possible NULL pointer dereference Anton Protopopov <a.s.protopopov@gmail.com> - 2016-02-17 17:30 +0100
  Re: [PATCH] mISDN: prevent possible NULL pointer dereference David Miller <davem@davemloft.net> - 2016-02-18 21:10 +0100

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