From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3BF5C1E480; Mon, 23 Jun 2025 13:37:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750685875; cv=none; b=fSgk+5BkVGvEvuyLXYJi+QMA5wBRXhpSrI+2ZeNKYS0KUkLA/78+7/5n/NRrzXqKa26pVBVX7UBw58QCaa7cLdeIAouwXeyiGQal4LdDf2F6TTl6DDbIuO98j1rwM0RbljkT5jK+M6LGHNlGXoLz1IuEu7Z8fqlvKZ4xL5QkhDw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750685875; c=relaxed/simple; bh=YFsNjT9+V7GxltH33hhY+ivgFLhPd8po6Eow8raFKSk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FHOP7bg+xOGSbd2RntO3k9Mu1hHFCiMgDpL1MykmJeykNvsYPef7cHsI97V93OO07NnnQtDhcoVliysmGxd1xd4EmYVBi8fZMM88lF9SFJ20iXxuLrpRFj68tkG6cg7qQdNT27LwRb26J9KK9WZ+FYJZnYsY2v/wg960PeEBIMg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nvcTPm2E; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nvcTPm2E" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C52AEC4CEEA; Mon, 23 Jun 2025 13:37:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750685875; bh=YFsNjT9+V7GxltH33hhY+ivgFLhPd8po6Eow8raFKSk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nvcTPm2Eamz03xk/LLt6LwIsgZSrk2b+ZgL6Vma+h03/GDf08l1uCio41afmydywh QT/iUh7GQ+hlcPKDtjsQ8BpZ5mWiZI8Vl2OsC8CGiy8MLV/SRkF8aaVd+N6dr+ZO6R MO/hLUInw/tU1J487EvitvYpp/VJ1Cmb+Agbx/UA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhang Yi , Theodore Tso , Sasha Levin Subject: [PATCH 6.15 289/592] ext4: prevent stale extent cache entries caused by concurrent get es_cache Date: Mon, 23 Jun 2025 15:04:07 +0200 Message-ID: <20250623130707.236717155@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250623130700.210182694@linuxfoundation.org> References: <20250623130700.210182694@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhang Yi [ Upstream commit f22a0ef2231a7d8374bb021eb86404d0e9de5a02 ] The EXT4_IOC_GET_ES_CACHE and EXT4_IOC_PRECACHE_EXTENTS currently invokes ext4_ext_precache() to preload the extent cache without holding the inode's i_rwsem. This can result in stale extent cache entries when competing with operations such as ext4_collapse_range() which calls ext4_ext_remove_space() or ext4_ext_shift_extents(). The problem arises when ext4_ext_remove_space() temporarily releases i_data_sem due to insufficient journal credits. During this interval, a concurrent EXT4_IOC_GET_ES_CACHE or EXT4_IOC_PRECACHE_EXTENTS may cache extent entries that are about to be deleted. As a result, these cached entries become stale and inconsistent with the actual extents. Loading the extents cache without holding the inode's i_rwsem or the mapping's invalidate_lock is not permitted besides during the writeback. Fix this by holding the i_rwsem during EXT4_IOC_GET_ES_CACHE and EXT4_IOC_PRECACHE_EXTENTS. Signed-off-by: Zhang Yi Link: https://patch.msgid.link/20250423085257.122685-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/extents.c | 2 ++ fs/ext4/ioctl.c | 8 +++++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 81e010a6c797c..828a78a9600a8 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4996,7 +4996,9 @@ int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo, } if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) { + inode_lock_shared(inode); error = ext4_ext_precache(inode); + inode_unlock_shared(inode); if (error) return error; fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE; diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index d17207386ead1..0e240013c84d2 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -1505,8 +1505,14 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return 0; } case EXT4_IOC_PRECACHE_EXTENTS: - return ext4_ext_precache(inode); + { + int ret; + inode_lock_shared(inode); + ret = ext4_ext_precache(inode); + inode_unlock_shared(inode); + return ret; + } case FS_IOC_SET_ENCRYPTION_POLICY: if (!ext4_has_feature_encrypt(sb)) return -EOPNOTSUPP; -- 2.39.5