This is a note to let you know that I've just added the patch titled
atm: idt77252: prevent use after free in dequeue_rx()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
atm-idt77252-prevent-use-after-free-in-dequeue_rx.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6c4b47bc22712840a7f030a4c309a7a91fa3403a
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Fri Aug 9 15:28:19 2024 +0300
atm: idt77252: prevent use after free in dequeue_rx()
[ Upstream commit a9a18e8f770c9b0703dab93580d0b02e199a4c79 ]
We can't dereference "skb" after calling vcc->push() because the skb
is released.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/atm/idt77252.c b/drivers/atm/idt77252.c
index 605e992d25df5..06e2fea1ffa92 100644
--- a/drivers/atm/idt77252.c
+++ b/drivers/atm/idt77252.c
@@ -1117,8 +1117,8 @@ dequeue_rx(struct idt77252_dev *card, struct rsq_entry *rsqe)
rpp->len += skb->len;
if (stat & SAR_RSQE_EPDU) {
+ unsigned int len, truesize;
unsigned char *l1l2;
- unsigned int len;
l1l2 = (unsigned char *) ((unsigned long) skb->data + skb->len - 6);
@@ -1188,14 +1188,15 @@ dequeue_rx(struct idt77252_dev *card, struct rsq_entry *rsqe)
ATM_SKB(skb)->vcc = vcc;
__net_timestamp(skb);
+ truesize = skb->truesize;
vcc->push(vcc, skb);
atomic_inc(&vcc->stats->rx);
- if (skb->truesize > SAR_FB_SIZE_3)
+ if (truesize > SAR_FB_SIZE_3)
add_rx_skb(card, 3, SAR_FB_SIZE_3, 1);
- else if (skb->truesize > SAR_FB_SIZE_2)
+ else if (truesize > SAR_FB_SIZE_2)
add_rx_skb(card, 2, SAR_FB_SIZE_2, 1);
- else if (skb->truesize > SAR_FB_SIZE_1)
+ else if (truesize > SAR_FB_SIZE_1)
add_rx_skb(card, 1, SAR_FB_SIZE_1, 1);
else
add_rx_skb(card, 0, SAR_FB_SIZE_0, 1);
