From: Chao Yu <yuchao0@huawei.com>
To: Yunlong Song <yunlong.song@huawei.com>, <jaegeuk@kernel.org>,
<chao@kernel.org>, <yunlong.song@icloud.com>
Cc: <miaoxie@huawei.com>, <bintian.wang@huawei.com>,
<shengyong1@huawei.com>, <heyunlei@huawei.com>,
<linux-f2fs-devel@lists.sourceforge.net>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3] f2fs: allocate buffer for decrypting filename to avoid panic
Date: Wed, 28 Feb 2018 10:49:12 +0800 [thread overview]
Message-ID: <786c9ff4-2214-b980-8a94-184345cee3b8@huawei.com> (raw)
In-Reply-To: <1519784380-83138-1-git-send-email-yunlong.song@huawei.com>
On 2018/2/28 10:19, Yunlong Song wrote:
> In some platforms (such as arm), high memory is used, then the
> decrypting filename will cause panic, the reason see commit
> 569cf1876a32e574ba8a7fb825cd91bafd003882 ("f2fs crypto: allocate buffer
> for decrypting filename"):
>
> We got dentry pages from high_mem, and its address space directly goes into the
> decryption path via f2fs_fname_disk_to_usr.
> But, sg_init_one assumes the address is not from high_mem, so we can get this
> panic since it doesn't call kmap_high but kunmap_high is triggered at the end.
>
> kernel BUG at ../../../../../../kernel/mm/highmem.c:290!
> Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
> ...
> (kunmap_high+0xb0/0xb8) from [<c0114534>] (__kunmap_atomic+0xa0/0xa4)
> (__kunmap_atomic+0xa0/0xa4) from [<c035f028>] (blkcipher_walk_done+0x128/0x1ec)
> (blkcipher_walk_done+0x128/0x1ec) from [<c0366c24>] (crypto_cbc_decrypt+0xc0/0x170)
> (crypto_cbc_decrypt+0xc0/0x170) from [<c0367148>] (crypto_cts_decrypt+0xc0/0x114)
> (crypto_cts_decrypt+0xc0/0x114) from [<c035ea98>] (async_decrypt+0x40/0x48)
> (async_decrypt+0x40/0x48) from [<c032ca34>] (f2fs_fname_disk_to_usr+0x124/0x304)
> (f2fs_fname_disk_to_usr+0x124/0x304) from [<c03056fc>] (f2fs_fill_dentries+0xac/0x188)
> (f2fs_fill_dentries+0xac/0x188) from [<c03059c8>] (f2fs_readdir+0x1f0/0x300)
> (f2fs_readdir+0x1f0/0x300) from [<c0218054>] (vfs_readdir+0x90/0xb4)
> (vfs_readdir+0x90/0xb4) from [<c0218418>] (SyS_getdents64+0x64/0xcc)
> (SyS_getdents64+0x64/0xcc) from [<c0105ba0>] (ret_fast_syscall+0x0/0x30)
>
> Howerver, later patches:
> commit e06f86e61d7a67fe6e826010f57aa39c674f4b1b ("f2fs crypto: avoid
> unneeded memory allocation in ->readdir")
>
> reverts the codes, which causes panic again in arm, so let's add part of
> the old patch again for dentry page.
>
Fixes: e06f86e61d7a ("f2fs crypto: avoid unneeded memory allocation in ->readdir")
> Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Looks good to me, you can add:
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Minor, we can just use 'git revert' to generate patch, so that commit title can
notice the patch are reverting buggy commit.
Thanks,
next prev parent reply other threads:[~2018-02-28 2:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-24 9:14 [PATCH] f2fs: allocate buffer for decrypting filename to avoid panic Yunlong Song
2018-02-24 18:32 ` Eric Biggers
2018-02-26 3:06 ` Yunlong Song
2018-02-26 3:42 ` Chao Yu
2018-02-26 2:57 ` [PATCH v2] " Yunlong Song
2018-02-27 10:40 ` Chao Yu
2018-02-28 2:19 ` [PATCH v3] " Yunlong Song
2018-02-28 2:49 ` Chao Yu [this message]
2018-02-28 3:17 ` [PATCH v4] Revert "f2fs crypto: avoid unneeded memory allocation in ->readdir" Yunlong Song
2018-02-28 5:48 ` Jaegeuk Kim
2018-02-28 9:50 ` Chao Yu
2018-03-01 2:50 ` Jaegeuk Kim
2018-03-01 3:02 ` Chao Yu
2018-02-28 12:32 ` Yunlong Song
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=786c9ff4-2214-b980-8a94-184345cee3b8@huawei.com \
--to=yuchao0@huawei.com \
--cc=bintian.wang@huawei.com \
--cc=chao@kernel.org \
--cc=heyunlei@huawei.com \
--cc=jaegeuk@kernel.org \
--cc=linux-f2fs-devel@lists.sourceforge.net \
--cc=linux-kernel@vger.kernel.org \
--cc=miaoxie@huawei.com \
--cc=shengyong1@huawei.com \
--cc=yunlong.song@huawei.com \
--cc=yunlong.song@icloud.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).