From: Ryusuke Konishi <konishi.ryusuke@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-nilfs@vger.kernel.org,
syzbot <syzbot+2e22057de05b9f3b30d8@syzkaller.appspotmail.com>,
syzkaller-bugs@googlegroups.com,
Jeongjun Park <aha310510@gmail.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH] nilfs2: Fix OOB in nilfs_set_de_type
Date: Tue, 16 Apr 2024 03:20:48 +0900 [thread overview]
Message-ID: <20240415182048.7144-1-konishi.ryusuke@gmail.com> (raw)
In-Reply-To: <000000000000209c9506161fd1d4@google.com>
From: Jeongjun Park <aha310510@gmail.com>
The size of the nilfs_type_by_mode array in the fs/nilfs2/dir.c file is
defined as "S_IFMT >> S_SHIFT", but the nilfs_set_de_type() function,
which uses this array, specifies the index to read from the array in the
same way as "(mode & S_IFMT) >> S_SHIFT".
static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode
*inode)
{
umode_t mode = inode->i_mode;
de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; // oob
}
However, when the index is determined this way, an out-of-bounds (OOB)
error occurs by referring to an index that is 1 larger than the array
size when the condition "mode & S_IFMT == S_IFMT" is satisfied.
Therefore, a patch to resize the nilfs_type_by_mode array should be
applied to prevent OOB errors.
Reported-by: syzbot+2e22057de05b9f3b30d8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2e22057de05b9f3b30d8
Fixes: 2ba466d74ed7 ("nilfs2: directory entry operations")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: stable@vger.kernel.org
---
Hi Andrew, please apply this as a bugfix.
This patch from Jeongjun fixes an array out-of-bounds access reported
by syzbot that can occur for filesystem images containing corrupted
directory inodes.
Thanks,
Ryusuke Konishi
fs/nilfs2/dir.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c
index bc846b904b68..aee40db7a036 100644
--- a/fs/nilfs2/dir.c
+++ b/fs/nilfs2/dir.c
@@ -240,7 +240,7 @@ nilfs_filetype_table[NILFS_FT_MAX] = {
#define S_SHIFT 12
static unsigned char
-nilfs_type_by_mode[S_IFMT >> S_SHIFT] = {
+nilfs_type_by_mode[(S_IFMT >> S_SHIFT) + 1] = {
[S_IFREG >> S_SHIFT] = NILFS_FT_REG_FILE,
[S_IFDIR >> S_SHIFT] = NILFS_FT_DIR,
[S_IFCHR >> S_SHIFT] = NILFS_FT_CHRDEV,
--
2.34.1
prev parent reply other threads:[~2024-04-15 18:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-15 10:09 [syzbot] [nilfs?] UBSAN: array-index-out-of-bounds in nilfs_add_link syzbot
2024-04-15 18:20 ` Ryusuke Konishi [this message]
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=20240415182048.7144-1-konishi.ryusuke@gmail.com \
--to=konishi.ryusuke@gmail.com \
--cc=aha310510@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nilfs@vger.kernel.org \
--cc=syzbot+2e22057de05b9f3b30d8@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.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 read-only IMAP folder(s) and NNTP newsgroup(s).