| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 26 Jul 2022 00:11:49 +0000
From: Vanessa Page <Vebpe@...look.com>
To: Yifei Liu <yifeliu@...stonybrook.edu>
CC: "ezk@...stonybrook.edu" <ezk@...stonybrook.edu>,
"madkar@...stonybrook.edu" <madkar@...stonybrook.edu>,
David Woodhouse <dwmw2@...radead.org>,
Richard Weinberger <richard@....at>,
"Matthew Wilcox (Oracle)" <willy@...radead.org>,
Kyeong Yoo <kyeong.yoo@...iedtelesis.co.nz>,
"linux-mtd@...ts.infradead.org" <linux-mtd@...ts.infradead.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] jffs2: correct logic when creating a hole in
jffs2_write_begin
Stop fucking emailing me you suck fuck. You want a password so you can hack my shit you broke motherfucker
People are not THAT stupid.
> On Jul 25, 2022, at 6:11 PM, Vanessa Page <Vebpe@...look.com> wrote:
>
> ๏ปฟYou lame ass stalking motherfucker. You are committing a crime and I have reported you to the police.
>
> Koop๐๐๐๐๐๐๐๐๐ด๐ด๐๐๐๐๐๐๐๐๐๐๐๐๐๐ณ๐๐ด๐๐๐๐๐คฃ๐คฃ๐๐๐๐ด๐๐คฅ๐คซ๐ฅ๐ฐ๐ฅต๐ฅต๐ก๐ก๐คฌ๐คฏ๐ญ๐ญ๐๐๐ฅณ๐คฉ๐ฅธ๐ฅธ๐ฅธ๐๐ฉ๐ฅบโน๏ธ๐ฃ๐๐๐๐๐ฃ๐ข๐ก๐ฅถ๐ฐ๐ฐ๐ฅ๐ฅ๐ถโ๐ซ๏ธ๐คฌ๐คฌ๐คฌ๐คฏ๐ถโ๐ซ๏ธ๐ฅถ๐ฐ๐ฐ๐คซ๐คซ๐๐คฏ๐คฏ๐คฏ
> Ooiggvklpoure๐คฌ๐คฌ๐คฌ๐คฌ๐คฌ๐คฌ๐คฌ๐คฌ๐คฌ๐คฌ๐คฏ๐คฏ๐คฏ๐คฏ๐คฏ๐คฏ๐คฏ๐คฏ๐คฏ๐คซ๐๐คฌ๐คฏ๐คฏ๐คฌ๐คฌ๐๐๐๐๐๐๐ฅธ๐คฉ๐ฅณ๐๐๐ฅบ๐ฉ๐ฉ๐คฉ๐ฅณ๐ฅณ๐๐๐ฃ๐๐ฉโน๏ธ๐๐ซ๐ค๐ญ๐คฌ๐คฉ๐คฉ๐ฅธ๐๐๐ฉ๐ก๐ต๐ช๐ง๐คฅ๐คฅ๐ฏ๐ต๐คฎ๐ฌ๐คฅ๐๐ค๐ค๐ถ๐ฒ๐คค๐ค๐ค๐ค๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ตโ๐ซ๐ค๐ผ๐ฝโ ๏ธ๐๐๐ป๐ป๐ป๐น๐น๐บ๐ฝ๐ฝ๐๐๐ป๐๐๐โ ๏ธโ ๏ธโ ๏ธโ ๏ธ
>
>> On Jul 25, 2022, at 1:04 AM, Vanessa Page <Vebpe@...look.com> wrote:
>>
>> ๏ปฟ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ๐ฅฐ๐๐๐๐๐๐๐๐๐โบ๏ธโบ๏ธโบ๏ธโบ๏ธโบ๏ธ๐๐๐๐๐๐๐ฅฐ๐๐๐๐๐๐๐โบ๏ธโบ๏ธโบ๏ธ๐๐๐๐ฅฐ๐ฅฐ๐โบ๏ธโบ๏ธ๐๐ฅฐ๐โบ๏ธ๐๐ฅฐ๐โบ๏ธโบ๏ธ๐๐ฅฐ๐ฅฐ๐โบ๏ธโบ๏ธ๐
>>
>> Sent from my iPhonโ๏ธ
>>
>>>> On Jul 25, 2022, at 1:01 AM, Yifei Liu <yifeliu@...stonybrook.edu> wrote:
>>>
>>> ๏ปฟBug description and fix:
>>>
>>> 1. Write data to a file, say all 1s from offset 0 to 16.
>>>
>>> 2. Truncate the file to a smaller size, say 8 bytes.
>>>
>>> 3. Write new bytes (say 2s) from an offset past the original size of the
>>> file, say at offset 20, for 4 bytes. This is supposed to create a "hole"
>>> in the file, meaning that the bytes from offset 8 (where it was truncated
>>> above) up to the new write at offset 20, should all be 0s (zeros).
>>>
>>> 4. flush all caches using "echo 3 > /proc/sys/vm/drop_caches" (or unmount
>>> and remount) the f/s.
>>>
>>> 5. Check the content of the file. It is wrong. The 1s that used to be
>>> between bytes 9 and 16, before the truncation, have REAPPEARED (they should
>>> be 0s).
>>>
>>> We wrote a script and helper C program to reproduce the bug
>>> (reproduce_jffs2_write_begin_issue.sh, write_file.c, and Makefile). We can
>>> make them available to anyone.
>>>
>>> The above example is shown when writing a small file within the same first
>>> page. But the bug happens for larger files, as long as steps 1, 2, and 3
>>> above all happen within the same page.
>>>
>>> The problem was traced to the jffs2_write_begin code, where it goes into an
>>> 'if' statement intended to handle writes past the current EOF (i.e., writes
>>> that may create a hole). The code computes a 'pageofs' that is the floor
>>> of the write position (pos), aligned to the page size boundary. In other
>>> words, 'pageofs' will never be larger than 'pos'. The code then sets the
>>> internal jffs2_raw_inode->isize to the size of max(current inode size,
>>> pageofs) but that is wrong: the new file size should be the 'pos', which is
>>> larger than both the current inode size and pageofs.
>>>
>>> Similarly, the code incorrectly sets the internal jffs2_raw_inode->dsize to
>>> the difference between the pageofs minus current inode size; instead it
>>> should be the current pos minus the current inode size. Finally,
>>> inode->i_size was also set incorrectly.
>>>
>>> The patch below fixes this bug. The bug was discovered using a new tool
>>> for finding f/s bugs using model checking, called MCFS (Model Checking File
>>> Systems).
>>>
>>> Signed-off-by: Yifei Liu <yifeliu@...stonybrook.edu>
>>> Signed-off-by: Erez Zadok <ezk@...stonybrook.edu>
>>> Signed-off-by: Manish Adkar <madkar@...stonybrook.edu>
>>> ---
>>> fs/jffs2/file.c | 15 +++++++--------
>>> 1 file changed, 7 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
>>> index ba86acbe12d3..0479096b96e4 100644
>>> --- a/fs/jffs2/file.c
>>> +++ b/fs/jffs2/file.c
>>> @@ -137,19 +137,18 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
>>> struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
>>> struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
>>> pgoff_t index = pos >> PAGE_SHIFT;
>>> - uint32_t pageofs = index << PAGE_SHIFT;
>>> int ret = 0;
>>>
>>> jffs2_dbg(1, "%s()\n", __func__);
>>>
>>> - if (pageofs > inode->i_size) {
>>> - /* Make new hole frag from old EOF to new page */
>>> + if (pos > inode->i_size) {
>>> + /* Make new hole frag from old EOF to new position */
>>> struct jffs2_raw_inode ri;
>>> struct jffs2_full_dnode *fn;
>>> uint32_t alloc_len;
>>>
>>> - jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
>>> - (unsigned int)inode->i_size, pageofs);
>>> + jffs2_dbg(1, "Writing new hole frag 0x%x-0x%x between current EOF and new position\n",
>>> + (unsigned int)inode->i_size, (uint32_t)pos);
>>>
>>> ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
>>> ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
>>> @@ -169,10 +168,10 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
>>> ri.mode = cpu_to_jemode(inode->i_mode);
>>> ri.uid = cpu_to_je16(i_uid_read(inode));
>>> ri.gid = cpu_to_je16(i_gid_read(inode));
>>> - ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
>>> + ri.isize = cpu_to_je32((uint32_t)pos);
>>> ri.atime = ri.ctime = ri.mtime = cpu_to_je32(JFFS2_NOW());
>>> ri.offset = cpu_to_je32(inode->i_size);
>>> - ri.dsize = cpu_to_je32(pageofs - inode->i_size);
>>> + ri.dsize = cpu_to_je32((uint32_t)pos - inode->i_size);
>>> ri.csize = cpu_to_je32(0);
>>> ri.compr = JFFS2_COMPR_ZERO;
>>> ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
>>> @@ -202,7 +201,7 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
>>> goto out_err;
>>> }
>>> jffs2_complete_reservation(c);
>>> - inode->i_size = pageofs;
>>> + inode->i_size = pos;
>>> mutex_unlock(&f->sem);
>>> }
>>>
>>> --
>>> 2.25.1
>>>
>>>
>>> ______________________________________________________
>>> Linux MTD discussion mailing list
>>> http://lists.infradead.org/mailman/listinfo/linux-mtd/
Powered by blists - more mailing lists