From: Jakub Kicinski Date: Fri, 17 Oct 2025 23:08:45 +0000 (-0700) Subject: Merge branch 'net-avoid-ehash-lookup-races' X-Git-Tag: v6.19-rc1~170^2~361 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=38f3cd3703df239badbd439e093b922efbc57ed1;p=thirdparty%2Fkernel%2Flinux.git Merge branch 'net-avoid-ehash-lookup-races' Xuanqiang Luo says: ==================== net: Avoid ehash lookup races After replacing R/W locks with RCU in commit 3ab5aee7fe84 ("net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls"), a race window emerged during the switch from reqsk/sk to sk/tw. Now that both timewait sock (tw) and full sock (sk) reside on the same ehash chain, it is appropriate to introduce hlist_nulls replace operations, to eliminate the race conditions caused by this window. Before this series of patches, I previously sent another version of the patch, attempting to avoid the issue using a lock mechanism. However, it seems there are some problems with that approach now, so I've switched to the "replace" method in the current patches to resolve the issue. For details, refer to: https://lore.kernel.org/netdev/20250903024406.2418362-1-xuanqiang.luo@linux.dev/ Before I encountered this type of issue recently, I found there had been several historical discussions about it. Therefore, I'm adding this background information for those interested to reference: 1. https://lore.kernel.org/lkml/20230118015941.1313-1-kerneljasonxing@gmail.com/ 2. https://lore.kernel.org/netdev/20230606064306.9192-1-duanmuquan@baidu.com/ ==================== Link: https://patch.msgid.link/20251015020236.431822-1-xuanqiang.luo@linux.dev Signed-off-by: Jakub Kicinski --- 38f3cd3703df239badbd439e093b922efbc57ed1