diff mbox series

[net,v2,1/1] net: stmmac: fix kernel panic due to NULL pointer dereference of buf->xdp

Message ID 20210825005742.980267-1-yoong.siang.song@intel.com (mailing list archive)
State Accepted
Commit 2b9fff64f03219d78044d1ab40dde8e3d42e968a
Delegated to: Netdev Maintainers
Headers show
Series [net,v2,1/1] net: stmmac: fix kernel panic due to NULL pointer dereference of buf->xdp | expand

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netdev/cc_maintainers warning 6 maintainers not CCed: andrii@kernel.org kafai@fb.com yhs@fb.com songliubraving@fb.com alexandre.torgue@foss.st.com kpsingh@kernel.org
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 20 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

Song Yoong Siang Aug. 25, 2021, 12:57 a.m. UTC
Ensure a valid XSK buffer before proceed to free the xdp buffer.

The following kernel panic is observed without this patch:

RIP: 0010:xp_free+0x5/0x40
Call Trace:
stmmac_napi_poll_rxtx+0x332/0xb30 [stmmac]
? stmmac_tx_timer+0x3c/0xb0 [stmmac]
net_rx_action+0x13d/0x3d0
__do_softirq+0xfc/0x2fb
? smpboot_register_percpu_thread+0xe0/0xe0
run_ksoftirqd+0x32/0x70
smpboot_thread_fn+0x1d8/0x2c0
kthread+0x169/0x1a0
? kthread_park+0x90/0x90
ret_from_fork+0x1f/0x30
---[ end trace 0000000000000002 ]---

Fixes: bba2556efad6 ("net: stmmac: Enable RX via AF_XDP zero-copy")
Cc: <stable@vger.kernel.org> # 5.13.x
Suggested-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
---
v2 changelog:
 - Add stable@vger.kernel.org in email cc list.
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org Aug. 25, 2021, 10:10 a.m. UTC | #1
Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Wed, 25 Aug 2021 08:57:42 +0800 you wrote:
> Ensure a valid XSK buffer before proceed to free the xdp buffer.
> 
> The following kernel panic is observed without this patch:
> 
> RIP: 0010:xp_free+0x5/0x40
> Call Trace:
> stmmac_napi_poll_rxtx+0x332/0xb30 [stmmac]
> ? stmmac_tx_timer+0x3c/0xb0 [stmmac]
> net_rx_action+0x13d/0x3d0
> __do_softirq+0xfc/0x2fb
> ? smpboot_register_percpu_thread+0xe0/0xe0
> run_ksoftirqd+0x32/0x70
> smpboot_thread_fn+0x1d8/0x2c0
> kthread+0x169/0x1a0
> ? kthread_park+0x90/0x90
> ret_from_fork+0x1f/0x30
> 
> [...]

Here is the summary with links:
  - [net,v2,1/1] net: stmmac: fix kernel panic due to NULL pointer dereference of buf->xdp
    https://git.kernel.org/netdev/net/c/2b9fff64f032

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 7b8404a21544..fa90bcdf4e45 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4914,6 +4914,10 @@  static int stmmac_rx_zc(struct stmmac_priv *priv, int limit, u32 queue)
 
 		prefetch(np);
 
+		/* Ensure a valid XSK buffer before proceed */
+		if (!buf->xdp)
+			break;
+
 		if (priv->extend_desc)
 			stmmac_rx_extended_status(priv, &priv->dev->stats,
 						  &priv->xstats,
@@ -4934,10 +4938,6 @@  static int stmmac_rx_zc(struct stmmac_priv *priv, int limit, u32 queue)
 			continue;
 		}
 
-		/* Ensure a valid XSK buffer before proceed */
-		if (!buf->xdp)
-			break;
-
 		/* XSK pool expects RX frame 1:1 mapped to XSK buffer */
 		if (likely(status & rx_not_ls)) {
 			xsk_buff_free(buf->xdp);