All of lore.kernel.org
 help / color / mirror / Atom feed
From: Eric Biggers <ebiggers@kernel.org>
To: Arnd Bergmann <arnd@arndb.de>, Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>,
	bpf@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-ppp@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	syzbot <syzbot+eb853b51b10f1befa0b7@syzkaller.appspotmail.com>,
	syzkaller-bugs@googlegroups.com
Subject: [PATCH] ppp: fix out-of-bounds access in bpf_prog_create()
Date: Wed,  4 Dec 2019 21:54:19 -0800	[thread overview]
Message-ID: <20191205055419.13435-1-ebiggers@kernel.org> (raw)
In-Reply-To: <20191205052220.GC1158@sol.localdomain>

From: Eric Biggers <ebiggers@google.com>

sock_fprog_kern::len is in units of struct sock_filter, not bytes.

Fixes: 3e859adf3643 ("compat_ioctl: unify copy-in of ppp filters")
Reported-by: syzbot+eb853b51b10f1befa0b7@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 drivers/net/ppp/ppp_generic.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 0cb1c2d0a8bc..3bf8a8b42983 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -564,8 +564,9 @@ static struct bpf_prog *get_filter(struct sock_fprog *uprog)
 		return NULL;
 
 	/* uprog->len is unsigned short, so no overflow here */
-	fprog.len = uprog->len * sizeof(struct sock_filter);
-	fprog.filter = memdup_user(uprog->filter, fprog.len);
+	fprog.len = uprog->len;
+	fprog.filter = memdup_user(uprog->filter,
+				   uprog->len * sizeof(struct sock_filter));
 	if (IS_ERR(fprog.filter))
 		return ERR_CAST(fprog.filter);
 
-- 
2.24.0


WARNING: multiple messages have this Message-ID (diff)
From: Eric Biggers <ebiggers@kernel.org>
To: Arnd Bergmann <arnd@arndb.de>, Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>,
	bpf@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-ppp@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	syzbot <syzbot+eb853b51b10f1befa0b7@syzkaller.appspotmail.com>,
	syzkaller-bugs@googlegroups.com
Subject: [PATCH] ppp: fix out-of-bounds access in bpf_prog_create()
Date: Thu, 05 Dec 2019 05:54:19 +0000	[thread overview]
Message-ID: <20191205055419.13435-1-ebiggers@kernel.org> (raw)
In-Reply-To: <20191205052220.GC1158@sol.localdomain>

From: Eric Biggers <ebiggers@google.com>

sock_fprog_kern::len is in units of struct sock_filter, not bytes.

Fixes: 3e859adf3643 ("compat_ioctl: unify copy-in of ppp filters")
Reported-by: syzbot+eb853b51b10f1befa0b7@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 drivers/net/ppp/ppp_generic.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 0cb1c2d0a8bc..3bf8a8b42983 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -564,8 +564,9 @@ static struct bpf_prog *get_filter(struct sock_fprog *uprog)
 		return NULL;
 
 	/* uprog->len is unsigned short, so no overflow here */
-	fprog.len = uprog->len * sizeof(struct sock_filter);
-	fprog.filter = memdup_user(uprog->filter, fprog.len);
+	fprog.len = uprog->len;
+	fprog.filter = memdup_user(uprog->filter,
+				   uprog->len * sizeof(struct sock_filter));
 	if (IS_ERR(fprog.filter))
 		return ERR_CAST(fprog.filter);
 
-- 
2.24.0

  reply	other threads:[~2019-12-05  5:55 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-17 18:49 KASAN: slab-out-of-bounds Read in bpf_prog_create syzbot
2019-09-17 18:49 ` syzbot
2019-09-28  3:15 ` Eric Biggers
2019-09-28  3:15   ` Eric Biggers
2019-12-05  5:22   ` Eric Biggers
2019-12-05  5:22     ` Eric Biggers
2019-12-05  5:54     ` Eric Biggers [this message]
2019-12-05  5:54       ` [PATCH] ppp: fix out-of-bounds access in bpf_prog_create() Eric Biggers
2019-12-05  9:07       ` Arnd Bergmann
2019-12-05  9:07         ` Arnd Bergmann
2019-12-05 22:45       ` David Miller
2019-12-05 22:45         ` David Miller
2019-12-05  9:08     ` KASAN: slab-out-of-bounds Read in bpf_prog_create Arnd Bergmann
2019-12-05  9:08       ` Arnd Bergmann

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=20191205055419.13435-1-ebiggers@kernel.org \
    --to=ebiggers@kernel.org \
    --cc=arnd@arndb.de \
    --cc=bpf@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-ppp@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=paulus@samba.org \
    --cc=syzbot+eb853b51b10f1befa0b7@syzkaller.appspotmail.com \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=viro@zeniv.linux.org.uk \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.