From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CEC5248EC6C; Wed, 23 Sep 2026 14:27:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790173628; cv=none; b=uEXIGiMdVMfgjP1bKLgcs3eHz5R3hlx8TUvX6K8P32A99F8bSF9Z3HdhWqWDaN4wMe0y6n0B4dXNKz4IiKRzkpV7SJuDmD0sXemgISqxN1t3rnDDu2t/zepGEzhq+SxDgIkHWfHOkJupooHNWUr64FXOgyIPngZZ/9xPgSBG5FI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790173628; c=relaxed/simple; bh=zqy/a+4YmYc9PYl4O3BLde3PJAs8CElymDB52Eom19E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tgDGkA4LyD4BvNw2TBYjqXcX29peojzAGH9C9gCcZ/FM+1OBupGH2oJRnfm7wFjKcxstUbO5grryXeFX1hNF46y8soUbhy59jB7B8fbJA5nv1sTUdpML4Fvc5hKNAW92LF5L5GnJu/CDkSueJN0DI9g3hxGp4palHalwb98B02U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zVnGNziq; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zVnGNziq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DD161F000FF; Wed, 23 Sep 2026 14:27:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790173626; bh=aOIjEaZ464BHQkNfF5i0pK31F6KsrDvxi5mP4pam01o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=zVnGNziqC4Nf3EW3UAAMn0r9NCUUvskAqivS/T3cq2w/lFpJBlmwwwe46dLA42SFF BkMihzGf+sYmanznF6/91UXKep/tueTLu74tN1dbjgIbVZywxbEF5sYA4u7y4FwQcl cb4jWHxgmSQhQZw0haypLXAI+MqekB1tz3vhnd9M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chengfeng Ye , Steffen Klassert Subject: [PATCH 7.2 306/438] xfrm: serialize state GC with device state flush Date: Wed, 23 Sep 2026 16:05:27 +0200 Message-ID: <20260923140652.707379542@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140644.756254324@linuxfoundation.org> References: <20260923140644.756254324@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chengfeng Ye commit 89fefad9f971bc637fb22373078144f2563c4be9 upstream. The deferred-device pass in xfrm_dev_state_flush() finds states under xfrm_state_dev_gc_lock, but drops the lock before calling xfrm_dev_state_free() because the driver callback may sleep. The device GC list does not hold an xfrm_state reference, so the state GC worker can destroy the same state concurrently. The race can proceed as follows: CPU 0 CPU 1 find x on the device GC list drop xfrm_state_dev_gc_lock read x->xso.dev xfrm_state_gc_destroy(x) xfrm_dev_state_free(x) xfrm_state_free(x) continue xfrm_dev_state_free(x) Both paths can invoke the driver callback and drop the device reference. CPU 0 can also access the xfrm_state after CPU 1 has freed it. KASAN reported: BUG: KASAN: slab-use-after-free in xfrm_dev_state_free+0x24c/0x2a0 Read of size 8 at addr ffff88810bbaa960 by task poc/102 Call Trace: xfrm_dev_state_free+0x24c/0x2a0 xfrm_dev_state_flush+0x353/0x400 xfrm_dev_event+0x26d/0x3a0 notifier_call_chain+0xc0/0x280 __dev_notify_flags+0x169/0x250 netif_change_flags+0xe7/0x160 dev_change_flags+0x96/0x220 devinet_ioctl+0x7f4/0x1880 Allocated by task 87: xfrm_state_alloc+0x1e/0x5c0 xfrm_add_sa+0xe7f/0x5820 xfrm_user_rcv_msg+0x4f3/0x940 Freed by task 57: kmem_cache_free+0xcb/0x3d0 xfrm_state_gc_task+0x4a8/0x650 process_one_work+0x63a/0x1070 Serialize xfrm_state destruction against the deferred-device pass with a mutex. Keep xfrm_state_dev_gc_lock limited to list operations and retain the existing callback and device-reference release ordering. Fixes: 07b87f9eea0c ("xfrm: Fix unregister netdevice hang on hardware offload.") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman --- net/xfrm/xfrm_state.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -226,6 +226,7 @@ static struct xfrm_state_afinfo __rcu *x static DEFINE_SPINLOCK(xfrm_state_gc_lock); static DEFINE_SPINLOCK(xfrm_state_dev_gc_lock); +static DEFINE_MUTEX(xfrm_state_gc_mutex); int __xfrm_state_delete(struct xfrm_state *x); @@ -632,8 +633,10 @@ static void xfrm_state_gc_task(struct wo synchronize_rcu(); + mutex_lock(&xfrm_state_gc_mutex); hlist_for_each_entry_safe(x, tmp, &gc_list, gclist) xfrm_state_gc_destroy(x); + mutex_unlock(&xfrm_state_gc_mutex); } static enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me) @@ -1000,6 +1003,7 @@ restart: out: spin_unlock_bh(&net->xfrm.xfrm_state_lock); + mutex_lock(&xfrm_state_gc_mutex); spin_lock_bh(&xfrm_state_dev_gc_lock); restart_gc: hlist_for_each_entry_safe(x, tmp, &xfrm_state_dev_gc_list, dev_gclist) { @@ -1014,6 +1018,7 @@ restart_gc: } spin_unlock_bh(&xfrm_state_dev_gc_lock); + mutex_unlock(&xfrm_state_gc_mutex); xfrm_flush_gc();