diff mbox series

[net] r8169: Fix possible ring buffer corruption on fragmented Tx packets

Message ID 574049c5-70a0-4dd3-85c3-40e396d00b2f@gmail.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series [net] r8169: Fix possible ring buffer corruption on fragmented Tx packets | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 905 this patch: 905
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 3 maintainers not CCed: pabeni@redhat.com kuba@kernel.org edumazet@google.com
netdev/build_clang success Errors and warnings before: 909 this patch: 909
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 909 this patch: 909
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 20 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-05-22--09-00 (tests: 1039)

Commit Message

Ken Milmore May 21, 2024, 9:20 p.m. UTC
An issue was found on the RTL8125b when transmitting small fragmented
packets, whereby invalid entries were inserted into the transmit ring
buffer, subsequently leading to calls to dma_unmap_single() with a null
address.

This was caused by rtl8169_start_xmit() not noticing changes to nr_frags
which may occur when small packets are padded (to work around hardware
quirks) in rtl8169_tso_csum_v2().

To fix this, postpone inspecting nr_frags until after any padding has been
applied.

Fixes: 9020845fb5d6 ("r8169: improve rtl8169_start_xmit")
Signed-off-by: Ken Milmore <ken.milmore@gmail.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Heiner Kallweit May 21, 2024, 10:07 p.m. UTC | #1
On 21.05.2024 23:20, Ken Milmore wrote:
> An issue was found on the RTL8125b when transmitting small fragmented
> packets, whereby invalid entries were inserted into the transmit ring
> buffer, subsequently leading to calls to dma_unmap_single() with a null
> address.
> 
> This was caused by rtl8169_start_xmit() not noticing changes to nr_frags
> which may occur when small packets are padded (to work around hardware
> quirks) in rtl8169_tso_csum_v2().
> 
> To fix this, postpone inspecting nr_frags until after any padding has been
> applied.
> 
> Fixes: 9020845fb5d6 ("r8169: improve rtl8169_start_xmit")

Meanwhile also netdev fixes should have the following:
CC: stable@vger.kernel.org
See https://www.kernel.org/doc/Documentation/process/stable-kernel-rules.rst

> Signed-off-by: Ken Milmore <ken.milmore@gmail.com>
> ---
>  drivers/net/ethernet/realtek/r8169_main.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index 86a6d4225bc..86ed9189d5f 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -4337,12 +4337,12 @@ static void rtl8169_doorbell(struct rtl8169_private *tp)
>  static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
>  				      struct net_device *dev)
>  {
> -	unsigned int frags = skb_shinfo(skb)->nr_frags;
>  	struct rtl8169_private *tp = netdev_priv(dev);
>  	unsigned int entry = tp->cur_tx % NUM_TX_DESC;
>  	struct TxDesc *txd_first, *txd_last;
>  	bool stop_queue, door_bell;
>  	u32 opts[2];
> +	unsigned int frags;
>  
netdev wants reverse xmas tree.

>  	if (unlikely(!rtl_tx_slots_avail(tp))) {
>  		if (net_ratelimit())
> @@ -4364,6 +4364,7 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
>  
>  	txd_first = tp->TxDescArray + entry;
>  
> +	frags = skb_shinfo(skb)->nr_frags;
>  	if (frags) {
>  		if (rtl8169_xmit_frags(tp, skb, opts, entry))
>  			goto err_dma_1;

Run get_maintainers.pl. The netdev subsystem maintainers are missing.

Apart from that lgtm.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 86a6d4225bc..86ed9189d5f 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -4337,12 +4337,12 @@  static void rtl8169_doorbell(struct rtl8169_private *tp)
 static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
 				      struct net_device *dev)
 {
-	unsigned int frags = skb_shinfo(skb)->nr_frags;
 	struct rtl8169_private *tp = netdev_priv(dev);
 	unsigned int entry = tp->cur_tx % NUM_TX_DESC;
 	struct TxDesc *txd_first, *txd_last;
 	bool stop_queue, door_bell;
 	u32 opts[2];
+	unsigned int frags;
 
 	if (unlikely(!rtl_tx_slots_avail(tp))) {
 		if (net_ratelimit())
@@ -4364,6 +4364,7 @@  static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
 
 	txd_first = tp->TxDescArray + entry;
 
+	frags = skb_shinfo(skb)->nr_frags;
 	if (frags) {
 		if (rtl8169_xmit_frags(tp, skb, opts, entry))
 			goto err_dma_1;