[PATCH net-next] net: Prevent use after free in netif_napi_set_irq_locked()
From: Dan Carpenter <hidden>
Date: 2025-03-03 12:02:18
Also in:
kernel-janitors, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The cpu_rmap_put() will call kfree() when the last reference is dropped
so it could result in a use after free when we dereference the same
pointer the next line. Move the cpu_rmap_put() after the dereference.
Fixes: bd7c00605ee0 ("net: move aRFS rmap management and CPU affinity to core")
Signed-off-by: Dan Carpenter <redacted>
---
net/core/dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index 9189c4a048d7..c102349e04ee 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -7072,8 +7072,8 @@ void netif_napi_set_irq_locked(struct napi_struct *napi, int irq) put_rmap: #ifdef CONFIG_RFS_ACCEL if (napi->dev->rx_cpu_rmap_auto) { - cpu_rmap_put(napi->dev->rx_cpu_rmap); napi->dev->rx_cpu_rmap->obj[napi->napi_rmap_idx] = NULL; + cpu_rmap_put(napi->dev->rx_cpu_rmap); napi->napi_rmap_idx = -1; } #endif
--
2.47.2