From e60b13e4f56fc56cc0dea845ce0711773d514149 Mon Sep 17 00:00:00 2001 From: Anton Protopopov Date: Wed, 17 Feb 2016 11:19:56 -0500 Subject: [PATCH] mISDN: prevent possible NULL pointer dereference 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 Signed-off-by: David S. Miller --- 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 8e2944784e00..afde4edef9ae 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; -- 2.25.1