diff mbox series

[net,v2,1/3] net: lantiq_xrx200: confirm skb is allocated before using

Message ID 20220815145740.12075-2-olek2@wp.pl (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net: lantiq_xrx200: fix errors under memory pressure | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 13 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Aleksander Jan Bajkowski Aug. 15, 2022, 2:57 p.m. UTC
xrx200_hw_receive() assumes build_skb() always works and goes straight
to skb_reserve(). However, build_skb() can fail under memory pressure.

Add a check in case build_skb() failed to allocate and return NULL.

Fixes: e015593573b3 ("net: lantiq_xrx200: convert to build_skb")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
---
 drivers/net/ethernet/lantiq_xrx200.c | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Jakub Kicinski Aug. 17, 2022, 3:41 a.m. UTC | #1
On Mon, 15 Aug 2022 16:57:38 +0200 Aleksander Jan Bajkowski wrote:
> +		netdev_err(net_dev, "failed to build skb\n");

I don't thinkg this is needed, is build_skb() using GFP_NOWARN?
Otherwise there will be an OOM splat anyway. Do check, I'm not sure.

If there won't be an OOM splat this line should be rate limited.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
index 5edb68a8aab1..6a83a6c19484 100644
--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -239,6 +239,13 @@  static int xrx200_hw_receive(struct xrx200_chan *ch)
 	}
 
 	skb = build_skb(buf, priv->rx_skb_size);
+	if (!skb) {
+		skb_free_frag(buf);
+		net_dev->stats.rx_dropped++;
+		netdev_err(net_dev, "failed to build skb\n");
+		return -ENOMEM;
+	}
+
 	skb_reserve(skb, NET_SKB_PAD);
 	skb_put(skb, len);