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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Amerigo Wang Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, Breno Leitao X-Mailer: b4 0.15-dev-42535 X-Developer-Signature: v=1; a=openpgp-sha256; l=1225; i=leitao@debian.org; h=from:subject:message-id; bh=E6+HafXHG5+k0knqEhjQ87TeghBra0OEM7+NgUaC8pU=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBnxZYRcnZeDEaJOkv2dtyjAlPJ6s1NIunWSs6/X eF8xlRwTXOJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCZ8WWEQAKCRA1o5Of/Hh3 beF/D/9+ebwAswXbXR2irz3Mkp+ze6xFiSt2WD29E0s7ZYCi8wpvgQr+O3tdI+nvB9LPMBBiUSA zSqhZuVhRArXgr2AzqXMlsPy+j+7fGEpGwUrC8zc7MCRMXbGSlOrGyVm5vFQOEOTdriurCc3W7y rgjeSmlZLIJtquAEZLeaLvEs382C5waYWpoCOId6v9qzDhKMrgyBZjt+7cQ9/4W9Aadvz3cxpZa ocYNxWBg5lCIYYySy+LrP0Zvbp9VhzTOzDIFMCGDcePqOpSM9L6uKAUse7c9jTDvZwHMk3ZRdn5 oeQ5VPcStJd8r0g7yJI1rQmp7JA3OU78cR2+ggQaqHyIO1Vtub9BDRWsMiqLI6GZ/FUHnOnBPAM 6RMDGDB+fZztdfZ3CgVDMWkVl6DFnsGHgvH6rHtJChwpnnRYtmYQ0IFEpSdVjaf7tztUmnP9oFt vRduPpwq5rfFqjCm4q3ISert4ZY0Y0rV/1w6dzq/xq8iwHGCY/6lx/Qjv0/yYwYEhWZO6uGDGLw j5w/r1MFE6ILAo12PYgJW/u9eBVQzpEy38zfcY4qMqs3OtJVVWH80u2/fnSOkp9cgEgLf1s9udy FQb0manj1C+XeE1c3xEkVDcZVo9mDhOiwisKJy9dPidjYv/Hag8IRYVsM0QTcVKepzhFEJq/YQo KZrFP6hH2jz01lQ== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Patchwork-Delegate: kuba@kernel.org The function __netpoll_send_skb() is being invoked without holding the RCU read lock. This oversight triggers a warning message when CONFIG_PROVE_RCU_LIST is enabled: net/core/netpoll.c:330 suspicious rcu_dereference_check() usage! netpoll_send_skb netpoll_send_udp write_ext_msg console_flush_all console_unlock vprintk_emit To prevent npinfo from disappearing unexpectedly, ensure that __netpoll_send_skb() is protected with the RCU read lock. Fixes: 2899656b494dcd1 ("netpoll: take rcu_read_lock_bh() in netpoll_send_skb_on_dev()") Signed-off-by: Breno Leitao --- net/core/netpoll.c | 1 + 1 file changed, 1 insertion(+) --- base-commit: 7eb172143d5508b4da468ed59ee857c6e5e01da6 change-id: 20250303-netpoll_rcu_v2-fed72eb0cb83 Best regards, diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 62b4041aae1ae..cac389105e2d1 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -326,6 +326,7 @@ static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) lockdep_assert_irqs_disabled(); + guard(rcu)(); dev = np->dev; npinfo = rcu_dereference_bh(dev->npinfo);