[PATCH v2 v5.10.y] Bluetooth: RFCOMM: Fix not validating setsockopt user input
From: Keerthana K <hidden>
Date: 2025-01-24 07:20:53
Also in:
linux-bluetooth, lkml, stable
Subsystem:
bluetooth subsystem, the rest · Maintainers:
Marcel Holtmann, Luiz Augusto von Dentz, Linus Torvalds
From: Luiz Augusto von Dentz <redacted>
[ 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 <redacted>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Luiz Augusto von Dentz <redacted>
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/ (local)]
Signed-off-by: Keerthana K <redacted>
---
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);
--
2.39.4