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 2D3AF47A62; Tue, 28 May 2024 02:19:01 +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=1716862742; cv=none; b=EXY/33YCx1XXaEV0YNFiZ/4Ga++DnRw6E6z+MF7ah20mPDPwQE2FxHja3PyXOMPUL+tXKYIEmh0T4AGvqQPKyKW4/8ZUP/RTnDZSr6u3gqSClJrZnbtw+0Hh7x1TWqiFsBrX1WcLRa+1zL2siZ/2fU6Dn4f8mLM7XlVelInvuYA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716862742; c=relaxed/simple; bh=Pjk67fPFjHtppc3wMlZuoY1CvZdQrDtIflgQnJLuOvE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jT90b7ATjZ1XXaIdotUk5WDGIXTNkPECXEKTBns8etnINxGmBEjCyWgvqxxekFeA8J3Ry448sDKGpvg1MincMJy1/DBCcS1RxZW74AjjgbsMsKp5cKHznfc7qzmwpeZgrWW6wSsNowl4Wf7A3Kx830mYx1aulqUvzK8R/sBPmlg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=njaMxIeh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="njaMxIeh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8EA0EC2BBFC; Tue, 28 May 2024 02:19:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716862741; bh=Pjk67fPFjHtppc3wMlZuoY1CvZdQrDtIflgQnJLuOvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=njaMxIeh/NAUMx7tGiJVWHzOSCFymOdHGaGmrQbpiZCMNpiK+1hQP+2IOx3dkMOPJ 3wqlj7v/imnz92EUyHLDzuXqxgwjsOn92BZRhW4SHoXQO08mQAKxJYSWit4XldUdCR sYJC2KxHyXK2rMv2zJ6WLuv5dak6YLDsf1nkXYGHUpKiabYIu05a6gi9I+nC/MaCBE MY5Eun43deRmjBpT74C62johDL5aI7QV7D5SDUo8+bY+DBh1AR5zVhsUZn3gj3zol8 6Bo+IOiw7VTsH8GAVZpccR6vQAZPP7Y+4TOJt+9VPaCGAsGG4w9U+9uC+/b2SnLF1a PN9hC5Fz41EGQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Baokun Li , Jan Kara , Theodore Ts'o , Sasha Levin , adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 6.6 3/4] ext4: fix uninitialized ratelimit_state->lock access in __ext4_fill_super() Date: Mon, 27 May 2024 22:18:52 -0400 Message-ID: <20240528021854.3905245-3-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240528021854.3905245-1-sashal@kernel.org> References: <20240528021854.3905245-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.32 Content-Transfer-Encoding: 8bit From: Baokun Li [ Upstream commit b4b4fda34e535756f9e774fb2d09c4537b7dfd1c ] In the following concurrency we will access the uninitialized rs->lock: ext4_fill_super ext4_register_sysfs // sysfs registered msg_ratelimit_interval_ms // Other processes modify rs->interval to // non-zero via msg_ratelimit_interval_ms ext4_orphan_cleanup ext4_msg(sb, KERN_INFO, "Errors on filesystem, " __ext4_msg ___ratelimit(&(EXT4_SB(sb)->s_msg_ratelimit_state) if (!rs->interval) // do nothing if interval is 0 return 1; raw_spin_trylock_irqsave(&rs->lock, flags) raw_spin_trylock(lock) _raw_spin_trylock __raw_spin_trylock spin_acquire(&lock->dep_map, 0, 1, _RET_IP_) lock_acquire __lock_acquire register_lock_class assign_lock_key dump_stack(); ratelimit_state_init(&sbi->s_msg_ratelimit_state, 5 * HZ, 10); raw_spin_lock_init(&rs->lock); // init rs->lock here and get the following dump_stack: ========================================================= INFO: trying to register non-static key. The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator. CPU: 12 PID: 753 Comm: mount Tainted: G E 6.7.0-rc6-next-20231222 #504 [...] Call Trace: dump_stack_lvl+0xc5/0x170 dump_stack+0x18/0x30 register_lock_class+0x740/0x7c0 __lock_acquire+0x69/0x13a0 lock_acquire+0x120/0x450 _raw_spin_trylock+0x98/0xd0 ___ratelimit+0xf6/0x220 __ext4_msg+0x7f/0x160 [ext4] ext4_orphan_cleanup+0x665/0x740 [ext4] __ext4_fill_super+0x21ea/0x2b10 [ext4] ext4_fill_super+0x14d/0x360 [ext4] [...] ========================================================= Normally interval is 0 until s_msg_ratelimit_state is initialized, so ___ratelimit() does nothing. But registering sysfs precedes initializing rs->lock, so it is possible to change rs->interval to a non-zero value via the msg_ratelimit_interval_ms interface of sysfs while rs->lock is uninitialized, and then a call to ext4_msg triggers the problem by accessing an uninitialized rs->lock. Therefore register sysfs after all initializations are complete to avoid such problems. Signed-off-by: Baokun Li Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20240102133730.1098120-1-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/super.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 83fc3f092a0c7..5baacb3058abd 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5556,19 +5556,15 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) if (err) goto failed_mount6; - err = ext4_register_sysfs(sb); - if (err) - goto failed_mount7; - err = ext4_init_orphan_info(sb); if (err) - goto failed_mount8; + goto failed_mount7; #ifdef CONFIG_QUOTA /* Enable quota usage during mount. */ if (ext4_has_feature_quota(sb) && !sb_rdonly(sb)) { err = ext4_enable_quotas(sb); if (err) - goto failed_mount9; + goto failed_mount8; } #endif /* CONFIG_QUOTA */ @@ -5594,7 +5590,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) ext4_msg(sb, KERN_INFO, "recovery complete"); err = ext4_mark_recovery_complete(sb, es); if (err) - goto failed_mount10; + goto failed_mount9; } if (test_opt(sb, DISCARD) && !bdev_max_discard_sectors(sb->s_bdev)) @@ -5611,15 +5607,17 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) atomic_set(&sbi->s_warning_count, 0); atomic_set(&sbi->s_msg_count, 0); + /* Register sysfs after all initializations are complete. */ + err = ext4_register_sysfs(sb); + if (err) + goto failed_mount9; + return 0; -failed_mount10: +failed_mount9: ext4_quotas_off(sb, EXT4_MAXQUOTAS); -failed_mount9: __maybe_unused +failed_mount8: __maybe_unused ext4_release_orphan_info(sb); -failed_mount8: - ext4_unregister_sysfs(sb); - kobject_put(&sbi->s_kobj); failed_mount7: ext4_unregister_li_request(sb); failed_mount6: -- 2.43.0