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 B4432383A0 for ; Wed, 15 May 2024 06:12:13 +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=1715753533; cv=none; b=C4c/ILanDM5czBzcPV+Byr7ba+IG/73onMniFUn8BA/4R1kp4lRkmKxoFAf2w/8HXPqgDYjtkI/Pak+o8/5ZcOwhH5lQiGla9oVfytt6YajVqMw8WF8NXxzUDqY7b0THRJr8M2lUjxznbeerGb/OD5T+RNERMWBYDSlqDKFOhsA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715753533; c=relaxed/simple; bh=h0A+98/4/Mbl1gFraVzzilprOH2dwXmDXoarNVSIjT4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pyhOM1meAC344NDOdAgTx7zUieWLatZwwZSQZXyE2nTMBT+NrMQPaU9fzJtbGC3jBDhNivLyCu3DsqQ/jBxvGxOvYzs38f/FTFWZ16qwhyhtEvXPX7MJlHyy4RCnYaT3QLXHtMMaQOTl1O8ttSwfV9LgukoX5e9ke8ECrTpqDCc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OHuEUf3e; 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="OHuEUf3e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB912C116B1; Wed, 15 May 2024 06:12:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1715753533; bh=h0A+98/4/Mbl1gFraVzzilprOH2dwXmDXoarNVSIjT4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=OHuEUf3eyJWAwUxyXWMMBLboTzTl1NB9QTvaa8QJhBRZhnLVKWQ0OBFxKpjyZiKbm x0SyZ1lFOE+c8umMy6d458VVMbbMIeHmrvffcI7uyQakkiYx7CxhYif9Q/DOSBMts6 ng8GZLwVqVG0sY0bvlvr0FcfsSDjyIi05byzG0XPDOfA/XCIIKdEMD3RbXpZDmta12 OEiZO8xrCNbVulq+YtWNA+DhTpas4O2/r5K4knKkAJUwm+ZP3YYoGXlhxITnpM+4Jw +pG+p8fOuafdmZQmbDpjc28Rv/Pl/VWjZFFiuuKnRQT6i1PC1BAygNx+iUtinxQGYI KfszlBSW2YoTA== Message-ID: <404a39af-b3b7-4898-a158-dd1e92f09a95@kernel.org> Date: Wed, 15 May 2024 14:12:08 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] f2fs: fix to do sanity check on i_nid for inline_data inode To: Jaegeuk Kim Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, syzbot+848062ba19c8782ca5c8@syzkaller.appspotmail.com References: <20240506103313.773503-1-chao@kernel.org> <20240506103313.773503-3-chao@kernel.org> <948ecc86-63f5-48bb-b71c-61d57cbf446c@kernel.org> <02a4e80f-a146-4862-8399-3db42979b8fb@kernel.org> <43f128b0-5151-4ae6-9bc0-438c7a9871e9@kernel.org> Content-Language: en-US From: Chao Yu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 2024/5/15 12:39, Jaegeuk Kim wrote: > On 05/15, Chao Yu wrote: >> On 2024/5/15 0:07, Jaegeuk Kim wrote: >>> 外部邮件/External Mail >>> >>> >>> On 05/11, Chao Yu wrote: >>>> On 2024/5/11 8:38, Jaegeuk Kim wrote: >>>>> On 05/10, Chao Yu wrote: >>>>>> On 2024/5/10 11:36, Jaegeuk Kim wrote: >>>>>>> On 05/10, Chao Yu wrote: >>>>>>>> On 2024/5/9 23:52, Jaegeuk Kim wrote: >>>>>>>>> On 05/06, Chao Yu wrote: >>>>>>>>>> syzbot reports a f2fs bug as below: >>>>>>>>>> >>>>>>>>>> ------------[ cut here ]------------ >>>>>>>>>> kernel BUG at fs/f2fs/inline.c:258! >>>>>>>>>> CPU: 1 PID: 34 Comm: kworker/u8:2 Not tainted 6.9.0-rc6-syzkaller-00012-g9e4bc4bcae01 #0 >>>>>>>>>> RIP: 0010:f2fs_write_inline_data+0x781/0x790 fs/f2fs/inline.c:258 >>>>>>>>>> Call Trace: >>>>>>>>>> f2fs_write_single_data_page+0xb65/0x1d60 fs/f2fs/data.c:2834 >>>>>>>>>> f2fs_write_cache_pages fs/f2fs/data.c:3133 [inline] >>>>>>>>>> __f2fs_write_data_pages fs/f2fs/data.c:3288 [inline] >>>>>>>>>> f2fs_write_data_pages+0x1efe/0x3a90 fs/f2fs/data.c:3315 >>>>>>>>>> do_writepages+0x35b/0x870 mm/page-writeback.c:2612 >>>>>>>>>> __writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650 >>>>>>>>>> writeback_sb_inodes+0x905/0x1260 fs/fs-writeback.c:1941 >>>>>>>>>> wb_writeback+0x457/0xce0 fs/fs-writeback.c:2117 >>>>>>>>>> wb_do_writeback fs/fs-writeback.c:2264 [inline] >>>>>>>>>> wb_workfn+0x410/0x1090 fs/fs-writeback.c:2304 >>>>>>>>>> process_one_work kernel/workqueue.c:3254 [inline] >>>>>>>>>> process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335 >>>>>>>>>> worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 >>>>>>>>>> kthread+0x2f2/0x390 kernel/kthread.c:388 >>>>>>>>>> ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 >>>>>>>>>> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 >>>>>>>>>> >>>>>>>>>> The root cause is: inline_data inode can be fuzzed, so that there may >>>>>>>>>> be valid blkaddr in its direct node, once f2fs triggers background GC >>>>>>>>>> to migrate the block, it will hit f2fs_bug_on() during dirty page >>>>>>>>>> writeback. >>>>>>>>>> >>>>>>>>>> Let's add sanity check on i_nid field for inline_data inode, meanwhile, >>>>>>>>>> forbid to migrate inline_data inode's data block to fix this issue. >>>>>>>>>> >>>>>>>>>> Reported-by: syzbot+848062ba19c8782ca5c8@syzkaller.appspotmail.com >>>>>>>>>> Closes: https://lore.kernel.org/linux-f2fs-devel/000000000000d103ce06174d7ec3@google.com >>>>>>>>>> Signed-off-by: Chao Yu >>>>>>>>>> --- >>>>>>>>>> fs/f2fs/f2fs.h | 2 +- >>>>>>>>>> fs/f2fs/gc.c | 6 ++++++ >>>>>>>>>> fs/f2fs/inline.c | 17 ++++++++++++++++- >>>>>>>>>> fs/f2fs/inode.c | 2 +- >>>>>>>>>> 4 files changed, 24 insertions(+), 3 deletions(-) >>>>>>>>>> >>>>>>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>>>>>>>>> index fced2b7652f4..c876813b5532 100644 >>>>>>>>>> --- a/fs/f2fs/f2fs.h >>>>>>>>>> +++ b/fs/f2fs/f2fs.h >>>>>>>>>> @@ -4146,7 +4146,7 @@ extern struct kmem_cache *f2fs_inode_entry_slab; >>>>>>>>>> * inline.c >>>>>>>>>> */ >>>>>>>>>> bool f2fs_may_inline_data(struct inode *inode); >>>>>>>>>> -bool f2fs_sanity_check_inline_data(struct inode *inode); >>>>>>>>>> +bool f2fs_sanity_check_inline_data(struct inode *inode, struct page *ipage); >>>>>>>>>> bool f2fs_may_inline_dentry(struct inode *inode); >>>>>>>>>> void f2fs_do_read_inline_data(struct page *page, struct page *ipage); >>>>>>>>>> void f2fs_truncate_inline_inode(struct inode *inode, >>>>>>>>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >>>>>>>>>> index e86c7f01539a..041957750478 100644 >>>>>>>>>> --- a/fs/f2fs/gc.c >>>>>>>>>> +++ b/fs/f2fs/gc.c >>>>>>>>>> @@ -1563,6 +1563,12 @@ static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, >>>>>>>>>> continue; >>>>>>>>>> } >>>>>>>>>> + if (f2fs_has_inline_data(inode)) { >>>>>>>>>> + iput(inode); >>>>>>>>>> + set_sbi_flag(sbi, SBI_NEED_FSCK); >>>>>>>>>> + continue; >>>>>>>>> >>>>>>>>> Any race condtion to get this as false alarm? >>>>>>>> >>>>>>>> Since there is no reproducer for the bug, I doubt it was caused by metadata >>>>>>>> fuzzing, something like this: >>>>>>>> >>>>>>>> - inline inode has one valid blkaddr in i_addr or in dnode reference by i_nid; >>>>>>>> - SIT/SSA entry of the block is valid; >>>>>>>> - background GC migrates the block; >>>>>>>> - kworker writeback it, and trigger the bug_on(). >>>>>>> >>>>>>> Wasn't detected by sanity_check_inode? >>>>>> >>>>>> I fuzzed non-inline inode w/ below metadata fields: >>>>>> - i_blocks = 1 >>>>>> - i_size = 2048 >>>>>> - i_inline |= 0x02 >>>>>> >>>>>> sanity_check_inode() doesn't complain. >>>>> >>>>> I mean, the below sanity_check_inode() can cover the fuzzed case? I'm wondering >>>> >>>> I didn't figure out a generic way in sanity_check_inode() to catch all fuzzed cases. >>> >>> >>> The patch described: >>> "The root cause is: inline_data inode can be fuzzed, so that there may >>> be valid blkaddr in its direct node, once f2fs triggers background GC >>> to migrate the block, it will hit f2fs_bug_on() during dirty page >>> writeback." >>> >>> Do you suspect the node block address was suddenly assigned after f2fs_iget()? >> >> No, I suspect that the image was fuzzed by tools offline, not in runtime after >> mount(). >> >>> Otherwise, it looks checking them in sanity_check_inode would be enough. >>> >>>> >>>> e.g. >>>> case #1 >>>> - blkaddr, its dnode, SSA and SIT are consistent >>>> - dnode.footer.ino points to inline inode >>>> - inline inode doesn't link to the donde >>>> >>>> Something like fuzzed special file, please check details in below commit: >>>> >>>> 9056d6489f5a ("f2fs: fix to do sanity check on inode type during garbage collection") >>>> >>>> case #2 >>>> - blkaddr, its dnode, SSA and SIT are consistent >>>> - blkaddr locates in inline inode's i_addr >> >> The image status is something like above as I described. > > Then, why not just checking the gc path only? Yes, we can. has_node_blocks() is added for using a quick check to see whether i_nid and inline_data flag are inconsistent, should we change this in a separated patch? Thanks, > >> >> Thanks, >> >>>> >>>> Thanks, >>>> >>>>> whether we really need to check it in the gc path. >>>>> >>>>>> >>>>>> Thanks, >>>>>> >>>>>>> >>>>>>>> >>>>>>>> Thoughts? >>>>>>>> >>>>>>>> Thanks, >>>>>>>> >>>>>>>>> >>>>>>>>>> + } >>>>>>>>>> + >>>>>>>>>> err = f2fs_gc_pinned_control(inode, gc_type, segno); >>>>>>>>>> if (err == -EAGAIN) { >>>>>>>>>> iput(inode); >>>>>>>>>> diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c >>>>>>>>>> index ac00423f117b..067600fed3d4 100644 >>>>>>>>>> --- a/fs/f2fs/inline.c >>>>>>>>>> +++ b/fs/f2fs/inline.c >>>>>>>>>> @@ -33,11 +33,26 @@ bool f2fs_may_inline_data(struct inode *inode) >>>>>>>>>> return !f2fs_post_read_required(inode); >>>>>>>>>> } >>>>>>>>>> -bool f2fs_sanity_check_inline_data(struct inode *inode) >>>>>>>>>> +static bool has_node_blocks(struct inode *inode, struct page *ipage) >>>>>>>>>> +{ >>>>>>>>>> + struct f2fs_inode *ri = F2FS_INODE(ipage); >>>>>>>>>> + int i; >>>>>>>>>> + >>>>>>>>>> + for (i = 0; i < DEF_NIDS_PER_INODE; i++) { >>>>>>>>>> + if (ri->i_nid[i]) >>>>>>>>>> + return true; >>>>>>>>>> + } >>>>>>>>>> + return false; >>>>>>>>>> +} >>>>>>>>>> + >>>>>>>>>> +bool f2fs_sanity_check_inline_data(struct inode *inode, struct page *ipage) >>>>>>>>>> { >>>>>>>>>> if (!f2fs_has_inline_data(inode)) >>>>>>>>>> return false; >>>>>>>>>> + if (has_node_blocks(inode, ipage)) >>>>>>>>>> + return false; >>>>>>>>>> + >>>>>>>>>> if (!support_inline_data(inode)) >>>>>>>>>> return true; >>>>>>>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c >>>>>>>>>> index c26effdce9aa..1423cd27a477 100644 >>>>>>>>>> --- a/fs/f2fs/inode.c >>>>>>>>>> +++ b/fs/f2fs/inode.c >>>>>>>>>> @@ -343,7 +343,7 @@ static bool sanity_check_inode(struct inode *inode, struct page *node_page) >>>>>>>>>> } >>>>>>>>>> } >>>>>>>>>> - if (f2fs_sanity_check_inline_data(inode)) { >>>>>>>>>> + if (f2fs_sanity_check_inline_data(inode, node_page)) { >>>>>>>>>> f2fs_warn(sbi, "%s: inode (ino=%lx, mode=%u) should not have inline_data, run fsck to fix", >>>>>>>>>> __func__, inode->i_ino, inode->i_mode); >>>>>>>>>> return false; >>>>>>>>>> -- >>>>>>>>>> 2.40.1