linux-kernel - [PATCH 4.9 30/70] btrfs: fix wrong address when faulting in pages in the search ioctl

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200921162036.491236637@linuxfoundation.org>
Date:   Mon, 21 Sep 2020 18:27:30 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, A L <mail@...hevalier.se>,
        Josef Bacik <josef@...icpanda.com>,
        Filipe Manana <fdmanana@...e.com>,
        David Sterba <dsterba@...e.com>
Subject: [PATCH 4.9 30/70] btrfs: fix wrong address when faulting in pages in the search ioctl

From: Filipe Manana <fdmanana@...e.com>

commit 1c78544eaa4660096aeb6a57ec82b42cdb3bfe5a upstream.

When faulting in the pages for the user supplied buffer for the search
ioctl, we are passing only the base address of the buffer to the function
fault_in_pages_writeable(). This means that after the first iteration of
the while loop that searches for leaves, when we have a non-zero offset,
stored in 'sk_offset', we try to fault in a wrong page range.

So fix this by adding the offset in 'sk_offset' to the base address of the
user supplied buffer when calling fault_in_pages_writeable().

Several users have reported that the applications compsize and bees have
started to operate incorrectly since commit a48b73eca4ceb9 ("btrfs: fix
potential deadlock in the search ioctl") was added to stable trees, and
these applications make heavy use of the search ioctls. This fixes their
issues.

Link: https://lore.kernel.org/linux-btrfs/632b888d-a3c3-b085-cdf5-f9bb61017d92@lechevalier.se/
Link: https://github.com/kilobyte/compsize/issues/34
Fixes: a48b73eca4ceb9 ("btrfs: fix potential deadlock in the search ioctl")
CC: stable@...r.kernel.org # 4.4+
Tested-by: A L <mail@...hevalier.se>
Reviewed-by: Josef Bacik <josef@...icpanda.com>
Signed-off-by: Filipe Manana <fdmanana@...e.com>
Reviewed-by: David Sterba <dsterba@...e.com>
Signed-off-by: David Sterba <dsterba@...e.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 fs/btrfs/ioctl.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2151,7 +2151,8 @@ static noinline int search_ioctl(struct
 	key.offset = sk->min_offset;

 	while (1) {
-		ret = fault_in_pages_writeable(ubuf, *buf_size - sk_offset);
+		ret = fault_in_pages_writeable(ubuf + sk_offset,
+					       *buf_size - sk_offset);
 		if (ret)
 			break;