From: Luiz Augusto von Dentz luiz.von.dentz@intel.com

[ Upstream commit a97de7bff13b1cc825c1b1344eaed8d6c2d3e695 ]

syzbot reported rfcomm_sock_setsockopt_old() is copying data without checking user input length.

BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline] BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt_old net/bluetooth/rfcomm/sock.c:632 [inline] BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt+0x893/0xa70 net/bluetooth/rfcomm/sock.c:673 Read of size 4 at addr ffff8880209a8bc3 by task syz-executor632/5064

Fixes: 9f2c8a03fbb3 ("Bluetooth: Replace RFCOMM link mode with security level") Fixes: bb23c0ab8246 ("Bluetooth: Add support for deferring RFCOMM connection setup") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org [Keerthana: No changes from v1 link to v1: https://lore.kernel.org/stable/2025012010-manager-dreamlike-b5c1@gregkh/] Signed-off-by: Keerthana K keerthana.kalyanasundaram@broadcom.com --- net/bluetooth/rfcomm/sock.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c index ae6f80730561..56360da0827c 100644 --- a/net/bluetooth/rfcomm/sock.c +++ b/net/bluetooth/rfcomm/sock.c @@ -657,7 +657,7 @@ static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname,

switch (optname) { case RFCOMM_LM: - if (copy_from_sockptr(&opt, optval, sizeof(u32))) { + if (bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen)) { err = -EFAULT; break; } @@ -692,7 +692,6 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname, struct sock *sk = sock->sk; struct bt_security sec; int err = 0; - size_t len; u32 opt;

BT_DBG("sk %p", sk); @@ -714,11 +713,9 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,

sec.level = BT_SECURITY_LOW;

- len = min_t(unsigned int, sizeof(sec), optlen); - if (copy_from_sockptr(&sec, optval, len)) { - err = -EFAULT; + err = bt_copy_from_sockptr(&sec, sizeof(sec), optval, optlen); + if (err) break; - }

if (sec.level > BT_SECURITY_HIGH) { err = -EINVAL; @@ -734,10 +731,9 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname, break; }

- if (copy_from_sockptr(&opt, optval, sizeof(u32))) { - err = -EFAULT; + err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen); + if (err) break; - }

if (opt) set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);