ntfs3.lists.linux.dev archive mirror
 help / color / mirror / Atom feed
From: Abdun Nihaal <abdun.nihaal@gmail.com>
To: almaz.alexandrovich@paragon-software.com
Cc: ntfs3@lists.linux.dev, linux-kernel@vger.kernel.org,
	skhan@linuxfoundation.org,
	linux-kernel-mentees@lists.linuxfoundation.org,
	Abdun Nihaal <abdun.nihaal@gmail.com>,
	syzbot+b892240eac461e488d51@syzkaller.appspotmail.com
Subject: [PATCH] fs/ntfs3: Fix slab-out-of-bounds read in ntfs_trim_fs
Date: Sat,  1 Oct 2022 12:30:24 +0530	[thread overview]
Message-ID: <20221001070024.1366018-1-abdun.nihaal@gmail.com> (raw)

Syzbot reports an out of bound access in ntfs_trim_fs.
The cause of this is using a loop termination condition that compares
window index (iw) with wnd->nbits instead of wnd->nwnd, due to which the
index used for wnd->free_bits exceeds the size of the array allocated.

Fix the loop condition.

Fixes: 3f3b442b5ad2 ("fs/ntfs3: Add bitmap")
Link: https://syzkaller.appspot.com/bug?extid=b892240eac461e488d51
Reported-by: syzbot+b892240eac461e488d51@syzkaller.appspotmail.com
Signed-off-by: Abdun Nihaal <abdun.nihaal@gmail.com>
---
 fs/ntfs3/bitmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ntfs3/bitmap.c b/fs/ntfs3/bitmap.c
index 1675c9a69788..629c1ee97268 100644
--- a/fs/ntfs3/bitmap.c
+++ b/fs/ntfs3/bitmap.c
@@ -1424,7 +1424,7 @@ int ntfs_trim_fs(struct ntfs_sb_info *sbi, struct fstrim_range *range)
 
 	down_read_nested(&wnd->rw_lock, BITMAP_MUTEX_CLUSTERS);
 
-	for (; iw < wnd->nbits; iw++, wbit = 0) {
+	for (; iw < wnd->nwnd; iw++, wbit = 0) {
 		CLST lcn_wnd = iw * wbits;
 		struct buffer_head *bh;
 
-- 
2.37.3


             reply	other threads:[~2022-10-01  7:02 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-01  7:00 Abdun Nihaal [this message]
2022-11-12 18:06 ` [PATCH] fs/ntfs3: Fix slab-out-of-bounds read in ntfs_trim_fs Konstantin Komarov

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=20221001070024.1366018-1-abdun.nihaal@gmail.com \
    --to=abdun.nihaal@gmail.com \
    --cc=almaz.alexandrovich@paragon-software.com \
    --cc=linux-kernel-mentees@lists.linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ntfs3@lists.linux.dev \
    --cc=skhan@linuxfoundation.org \
    --cc=syzbot+b892240eac461e488d51@syzkaller.appspotmail.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).