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| author | Marcel Holtmann <marcel@holtmann.org> | 2007-05-05 02:35:59 +0400 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2007-05-05 02:35:59 +0400 |
| commit | 0878b6667f28772aa7d6b735abff53efc7bf6d91 (patch) | |
| tree | 5a1dbfb35f679335fbec4cbd17dfe64926db7750 /net/bluetooth/l2cap.c | |
| parent | dc87c3985e9b442c60994308a96f887579addc39 (diff) | |
| download | linux-0878b6667f28772aa7d6b735abff53efc7bf6d91.tar.xz | |
[Bluetooth] Fix L2CAP and HCI setsockopt() information leaks
The L2CAP and HCI setsockopt() implementations have a small information
leak that makes it possible to leak kernel stack memory to userspace.
If the optlen parameter is 0, no data will be copied by copy_from_user(),
but the uninitialized stack buffer will be read and stored later. A call
to getsockopt() can now retrieve the leaked information.
To fix this problem the stack buffer given to copy_from_user() must be
initialized with the current settings.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth/l2cap.c')
| -rw-r--r-- | net/bluetooth/l2cap.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index a5867879b615..a59b1fb63b76 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -954,11 +954,17 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, ch switch (optname) { case L2CAP_OPTIONS: + opts.imtu = l2cap_pi(sk)->imtu; + opts.omtu = l2cap_pi(sk)->omtu; + opts.flush_to = l2cap_pi(sk)->flush_to; + opts.mode = 0x00; + len = min_t(unsigned int, sizeof(opts), optlen); if (copy_from_user((char *) &opts, optval, len)) { err = -EFAULT; break; } + l2cap_pi(sk)->imtu = opts.imtu; l2cap_pi(sk)->omtu = opts.omtu; break; |