From nobody Fri Jun 19 09:06:01 2026 Received: from mout-y-209.mailbox.org (mout-y-209.mailbox.org [91.198.250.237]) (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 6339E340286 for ; Fri, 24 Apr 2026 21:00:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.198.250.237 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777064428; cv=none; b=bYzpU+XDiblzCbaiozu9UhejNgZNARrwXFmsziMoqUlZ8ImP1f1L3isFqrvCz0hj6XCMglMmhJxBfohqdrw9c+4+0r//mckKl+NOHRofjjVwEatZoNWvAerYAFGjjaQx/QJaLBL0R9XzlnurRtH71gNpiK5TZtaSlatDC4ouZT4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777064428; c=relaxed/simple; bh=GnklaVG1HZALMendW9g8Sa2yaS89I2Gv0vV4kpkUNLY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=X1Hb3ucnzyZ9NpJVeZpdisyfmE3IqypFoTukIjcgREL/8xkpnddyQj5BmAhvl5b/I5xsrsb/dn7af6/ldib52uT6hKttlUZDjH/5EBinn4/B6tGYj/KhzRlLV4BkAEdgpumoBRAWo/WVwnpyvvn4uosKVBj2eMhyMhSmLZqVkj4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=f2UU/0Jc; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=Yoc27cye; arc=none smtp.client-ip=91.198.250.237 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="f2UU/0Jc"; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="Yoc27cye" Received: from smtp1.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:b231:465::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-y-209.mailbox.org (Postfix) with ESMTPS id 4g2Q905hMVzB0Zy; Fri, 24 Apr 2026 22:51:00 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1777063860; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=/pG1pCo4+FF95dTFeUArkBuK0CH+WenrNvsN4sFI2Lc=; b=f2UU/0JcJfdGSzeP0dTHr27v/qUpgcYoZgJ5LZXUIPt5uKxhkUVBwdlJ6MdBx8iZFQ3nHO I/5qpLkl/usmDmRXJnbvMRcfD2PNinJR28H/kBcFx3swLpgHORHWXOFIYjYNxd3o4yu26x YSCvgEq2P4hIjCcaq3Uz1B56PChrzY4kQ4+WPYf88xVwMrYFeFRhj3EKO1+KrMrxOkhjDT 1abjK7VO/tMV5+xp3AZMIDg8MTIxuh9lQCp3xM92LQZD310DYGsFj0ex9bC+NYKrl4JBRr CQLXlXyn0QPfrCz5+ZsHPJqwYP3wSSsa0QVnPfUoSZOeh3XUYNXO/rYa5hZhKg== Authentication-Results: outgoing_mbo_mout; dkim=pass header.d=mailbox.org header.s=mail20150812 header.b=Yoc27cye; spf=pass (outgoing_mbo_mout: domain of mashiro.chen@mailbox.org designates 2001:67c:2050:b231:465::1 as permitted sender) smtp.mailfrom=mashiro.chen@mailbox.org From: Mashiro Chen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1777063858; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=/pG1pCo4+FF95dTFeUArkBuK0CH+WenrNvsN4sFI2Lc=; b=Yoc27cyefuokd1aWTNfLCTcGAw3+dnAVobxz0OwguRSXvLPYjEMOI/ndCr1ou8VrPf6ay+ T2JFg730xehnjXRfqPGC3CjWVEwF+xHjoi0nmdI/t+8ceJ28rV9YFHt74TM0htG7dwwwHB wbYomThEoxD37OVelPs1U5MZs5hiC6EfzftYXmkrzDlXoGBS3ztFP+7lr9xnQPMDtQer8C DPd+NNQjp+SqCKdWPpsvsvmQr/J65owMHvtCO6GKgLe/FeQz8Yt2bLjeM7LRwtBd//aTWU O1ix+oVsNPLyZj34pib7zdNbFWdtvF4B9/W7WXcIQNXLv2R5ne3cJa5e0GAujQ== To: shaggy@kernel.org Cc: vulab@iscas.ac.cn, mashiro.chen@mailbox.org, liaoyuanhong@vivo.com, kees@kernel.org, jfs-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org, syzbot+6cc93ec9a4035badb85f@syzkaller.appspotmail.com Subject: [PATCH] jfs: fix use-after-free on log shutdown Date: Sat, 25 Apr 2026 04:50:46 +0800 Message-ID: <20260424205046.41811-1-mashiro.chen@mailbox.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-MBO-RS-META: g6kafxuyh5j1xohtausn3agmuu9stgki X-MBO-RS-ID: 06b693b6acbc2de5534 X-Rspamd-Queue-Id: 4g2Q905hMVzB0Zy Content-Type: text/plain; charset="utf-8" During JFS log shutdown, log buffer pages can be freed while lower-layer loop workers are still copying from them, triggering a use-after-free reported by syzbot in copy_folio_from_iter_atomic(). Track in-flight log I/O in struct jfs_log and wait for completion before freeing log buffers. Add io_inflight/io_waitq, increment io_inflight before submitting BIOs in lbmRead() and lbmStartIO(), and decrement it from lbmIODone() on all completion paths, including READ and DIRECT early-return paths. This closes the teardown race between buffer page free and late I/O completion. Reported-by: syzbot+6cc93ec9a4035badb85f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3D6cc93ec9a4035badb85f Signed-off-by: Mashiro Chen --- fs/jfs/jfs_logmgr.c | 17 +++++++++++++++-- fs/jfs/jfs_logmgr.h | 2 ++ 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c index ada00d5bc214..a45c8e2559e4 100644 --- a/fs/jfs/jfs_logmgr.c +++ b/fs/jfs/jfs_logmgr.c @@ -1806,6 +1806,8 @@ static int lbmLogInit(struct jfs_log * log) * avoid deadlock here. */ init_waitqueue_head(&log->free_wait); + init_waitqueue_head(&log->io_waitq); + atomic_set(&log->io_inflight, 0); =20 log->lbuf_free =3D NULL; =20 @@ -1857,6 +1859,8 @@ static void lbmLogShutdown(struct jfs_log * log) =20 jfs_info("lbmLogShutdown: log:0x%p", log); =20 + wait_event(log->io_waitq, !atomic_read(&log->io_inflight)); + lbuf =3D log->lbuf_free; while (lbuf) { struct lbuf *next =3D lbuf->l_freelist; @@ -1978,6 +1982,7 @@ static int lbmRead(struct jfs_log * log, int pn, stru= ct lbuf ** bpp) =20 bio->bi_end_io =3D lbmIODone; bio->bi_private =3D bp; + atomic_inc(&log->io_inflight); /*check if journaling to disk has been disabled*/ if (log->no_integrity) { bio->bi_iter.bi_size =3D 0; @@ -2124,6 +2129,7 @@ static void lbmStartIO(struct lbuf * bp) =20 bio->bi_end_io =3D lbmIODone; bio->bi_private =3D bp; + atomic_inc(&log->io_inflight); =20 /* check if journaling to disk has been disabled */ if (log->no_integrity) { @@ -2170,7 +2176,7 @@ static void lbmIODone(struct bio *bio) { struct lbuf *bp =3D bio->bi_private; struct lbuf *nextbp, *tail; - struct jfs_log *log; + struct jfs_log *log =3D bp->l_log; unsigned long flags; =20 /* @@ -2201,6 +2207,9 @@ static void lbmIODone(struct bio *bio) /* wakeup I/O initiator */ LCACHE_WAKEUP(&bp->l_ioevent); =20 + if (atomic_dec_and_test(&log->io_inflight)) + wake_up(&log->io_waitq); + return; } =20 @@ -2220,12 +2229,13 @@ static void lbmIODone(struct bio *bio) INCREMENT(lmStat.pagedone); =20 /* update committed lsn */ - log =3D bp->l_log; log->clsn =3D (bp->l_pn << L2LOGPSIZE) + bp->l_ceor; =20 if (bp->l_flag & lbmDIRECT) { LCACHE_WAKEUP(&bp->l_ioevent); LCACHE_UNLOCK(flags); + if (atomic_dec_and_test(&log->io_inflight)) + wake_up(&log->io_waitq); return; } =20 @@ -2305,6 +2315,9 @@ static void lbmIODone(struct bio *bio) =20 LCACHE_UNLOCK(flags); /* unlock+enable */ } + + if (atomic_dec_and_test(&log->io_inflight)) + wake_up(&log->io_waitq); } =20 int jfsIOWait(void *arg) diff --git a/fs/jfs/jfs_logmgr.h b/fs/jfs/jfs_logmgr.h index 8b8994e48cd0..59cb0aca99c5 100644 --- a/fs/jfs/jfs_logmgr.h +++ b/fs/jfs/jfs_logmgr.h @@ -400,6 +400,8 @@ struct jfs_log { uuid_t uuid; /* 16: 128-bit uuid of log device */ =20 int no_integrity; /* 3: flag to disable journaling to disk */ + atomic_t io_inflight; + wait_queue_head_t io_waitq; }; =20 /* --=20 2.54.0