From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 3D68F44F543; Wed, 30 Sep 2026 07:02:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790751780; cv=none; b=RsA61Kx4v6r/qLGHm7bj/BUeSEufKeyBiRQD098yTjfI8REGsvCQ5H0kZmOjin/DsU3Y0JgGkmf5JbVMwCqsl6SvgUkvBqr1ygo7KfjRfnWOSdpBQKqSYzoDxpFI6XmMs8Ekdh8l+KUg/XkaFROVq9kGkw2McZczKSNKMYCr154= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790751780; c=relaxed/simple; bh=I+oRYE1hByn30bYkUkL6uPnSEbWCuf6g31HZNmsdTtE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Xbrv40Ac5qTt4m3ovVEhIyczK485LCfKp//dqWiAgNRPHX884CLM/xMaXl4rdMcrqH/X+gRTyK8kKDyV/Atb4Ow+D2WU9lRwaNJ/O8L1TnF4V4o9aVk3AAgHnSwJtl9UW3Qaha6nG7NQfvgE6jViZO5/jr+4rxgnuzKwcX4Mhto= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=mn3CBeOA; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="mn3CBeOA" Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 68TNZqV4120194; Wed, 30 Sep 2026 07:02:44 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=w15/hm9CPDsPrawR9 7OAtf/xNAjIDheAVnZI3Epe7xc=; b=mn3CBeOA3Meu1ttpcRNbnGsjjxvhaayvw YZs+rCTLWLCBcAtJ5CWUxuVZ1l117ZoQeGCSPVEVs8qPuv29EQpJm79ZKDnvGNFr 9+cq4FH6N9k4piihRWazT3ggqdn3ZOWt0dj5b+C0n7CEqGYEHZLJwNvLt1Mx8nUv igtwm73Yb4DZmGMEyouYn2SEhJb9W6kDuSaogLT9ZJIUTCczDfRkCwhYqjO8EEzi Kl9FXjvZZRR791me3bueHOa7CEPMKLcPmgACi0nM9EFdX8x5hVopqwq/eizi63pL mgy3SvK1HbfPtGomQ87P1EwZsQIysVJADwDECyvGFg/hbtNAuXgRw== Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4gx4feampr-1 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Wed, 30 Sep 2026 07:02:43 +0000 (GMT) Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.18.1.11/8.18.1.11) with ESMTP id 68U4rag22549180; Wed, 30 Sep 2026 07:02:43 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4gxrrwddpe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 30 Sep 2026 07:02:42 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (smtpav06.fra02v.mail.ibm.com [10.20.54.105]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 68U72cab31916608 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 30 Sep 2026 07:02:39 GMT Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A508F2004B; Wed, 30 Sep 2026 07:02:38 +0000 (GMT) Received: from smtpav06.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 59D9320049; Wed, 30 Sep 2026 07:02:38 +0000 (GMT) Received: from t83lp71.lnxne.boe (unknown [9.87.84.240]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 30 Sep 2026 07:02:38 +0000 (GMT) From: Nagamani PV To: andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: wintera@linux.ibm.com, aswin@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, kees@kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, Nagamani PV , stable@vger.kernel.org, Sashiko Subject: [PATCH net v4 1/2] s390/ctcm: Fix timer corruption in fsm_addtimer() Date: Wed, 30 Sep 2026 09:02:33 +0200 Message-ID: <20260930070234.569500-2-nagamani@linux.ibm.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260930070234.569500-1-nagamani@linux.ibm.com> References: <20260930070234.569500-1-nagamani@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Authority-Analysis: v=2.4 cv=FYWiV5+6 c=1 sm=1 tr=0 ts=6abcb414 cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=VdqzKS8jKosA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=c92rfblmAAAA:8 a=VnNF1IyMAAAA:8 a=VwQbUJbxAAAA:8 a=T_NMYt6YcsbJOU4cA00A:9 a=GvGzcOZaWPEFPQC_NcjD:22 X-Proofpoint-Spam-Info: AW1haW4tMjYwOTMwMDAyNiBTYWx0ZWRfXwLEr6Udz+830 IgLIJMvqSqshGXTWcfHTvpBsxzd9Pj1emKbjlo2EOJlRUsy35wBli/R5zX1/7L03fE2R99JbhOH t+viu2c5uiVGBNv1Qq2tzl0W0T1VNzk= X-Proofpoint-ORIG-GUID: jHfV2Zs45mM7mZ9W7QtA7_1ykMdW-j6C X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTMwMDAyNiBTYWx0ZWRfX2C9T6E03ZsI0 lYWkWJK+PkLelP+JZ7Xw23b2LVIB7yWE/RNJ7q9s2GX+1Zcw0N7buGYLdQUkQ074avv8zLrBGKL 9iPiXWLr7VLJ3hRXn6cT/lGUZLSkTyMR0pL4BYlOXUFccH0hFn+1up0b60HGYl83Mhn17/D08bk G3fc4jahQf1S1VOPHR+XCPhEAI8KkAs7GBpOFIZ5Svf20bT4utuvxDXFDn+F1izrkCWR9Eiymca LvLz2bNmYMuCTi8nm2YKpUCMCVqULI+sxjkkgS5y14Snzd+qL1Rc3Jq6SP9RgtJKY8L07o4YNlg VMpvbLqOke5XIzti1LhM6O5i5eVW3ENzV8GLrUi2TppoCSpQbJWL2XMItxA7AWBc1w54QMwIM2R yyiHSaU4UlQaHj3Q0S70mspyOt7XMrEn4yqzp9aifwN9qbBW7+5ok4SozpfMcJLCV2dbsfqh30s Yk7kHl88IKM97DPaNSw== X-Proofpoint-GUID: 0-H4ws03r4nC5qy37iYWw7yAE2PvppIe X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-09-29_05,2026-09-21_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 clxscore=1015 impostorscore=0 spamscore=0 phishscore=0 priorityscore=1501 malwarescore=0 bulkscore=0 lowpriorityscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2609300026 fsm_addtimer() calls timer_setup() unconditionally before add_timer(). If called on an already-pending timer, timer_setup() re-initializes the timer's list_head fields while the timer is still enqueued in the wheel, corrupting the timer list. The timer is already initialized once by fsm_settimer() which calls timer_setup() correctly. Multiple callsites invoke fsm_addtimer() without a preceding fsm_deltimer(), including ctcm_main.c ctcmpc_send_sweep_req() and ctcm_mpc.c mpc_action_side_xid(), making the redundant timer_setup() in fsm_addtimer() a real corruption risk. Remove the redundant timer_setup() calls from fsm_addtimer() and fsm_modtimer(), and replace add_timer() with mod_timer() which safely handles both pending and non-pending timers atomically without corrupting the timer wheel. Fixes: e99e88a9d2b0 ("treewide: setup_timer() -> timer_setup()") Cc: stable@vger.kernel.org Reported-by: Sashiko Link: https://sashiko.dev/#/patchset/20260803182736.2356374-1-nagamani@linux.ibm.com?part=1 Reviewed-by: Aswin Karuvally Tested-by: Aswin Karuvally Signed-off-by: Nagamani PV --- Changes in v4: - No changes to this patch. Changes in v3: - No changes to this patch. Changes in v2: - Fix function name ctcm_send_sweep() -> ctcmpc_send_sweep_req() in the commit message. - Call mod_timer() then return 0 explicitly, preserving the "Always returns 0" contract documented in fsm.h. --- drivers/s390/net/fsm.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/s390/net/fsm.c b/drivers/s390/net/fsm.c index 9b8622aef807..936ed0bc8401 100644 --- a/drivers/s390/net/fsm.c +++ b/drivers/s390/net/fsm.c @@ -171,11 +171,9 @@ fsm_addtimer(fsm_timer *this, int millisec, int event, void *arg) this->fi->name, this, millisec); #endif - timer_setup(&this->tl, fsm_expire_timer, 0); this->expire_event = event; this->event_arg = arg; - this->tl.expires = jiffies + (millisec * HZ) / 1000; - add_timer(&this->tl); + mod_timer(&this->tl, jiffies + msecs_to_jiffies(millisec)); return 0; } @@ -189,12 +187,9 @@ fsm_modtimer(fsm_timer *this, int millisec, int event, void *arg) this->fi->name, this, millisec); #endif - timer_delete(&this->tl); - timer_setup(&this->tl, fsm_expire_timer, 0); this->expire_event = event; this->event_arg = arg; - this->tl.expires = jiffies + (millisec * HZ) / 1000; - add_timer(&this->tl); + mod_timer(&this->tl, jiffies + msecs_to_jiffies(millisec)); } EXPORT_SYMBOL(init_fsm); -- 2.53.0