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authorSungwoo Kim <iam@sung-woo.kim>2022-11-18 23:01:47 +0300
committerLuiz Augusto von Dentz <luiz.von.dentz@intel.com>2022-12-03 00:09:30 +0300
commitbcd70260ef56e0aee8a4fc6cd214a419900b0765 (patch)
tree67f88bda7c13a0d952a7f16f81b6e7a97d1c166d /net/bluetooth/l2cap_core.c
parent696bd3622138bfad0dda9ad7311886b8e6f5ea10 (diff)
downloadlinux-bcd70260ef56e0aee8a4fc6cd214a419900b0765.tar.xz
Bluetooth: L2CAP: Fix u8 overflow
By keep sending L2CAP_CONF_REQ packets, chan->num_conf_rsp increases multiple times and eventually it will wrap around the maximum number (i.e., 255). This patch prevents this by adding a boundary check with L2CAP_MAX_CONF_RSP Btmon log: Bluetooth monitor ver 5.64 = Note: Linux version 6.1.0-rc2 (x86_64) 0.264594 = Note: Bluetooth subsystem version 2.22 0.264636 @ MGMT Open: btmon (privileged) version 1.22 {0x0001} 0.272191 = New Index: 00:00:00:00:00:00 (Primary,Virtual,hci0) [hci0] 13.877604 @ RAW Open: 9496 (privileged) version 2.22 {0x0002} 13.890741 = Open Index: 00:00:00:00:00:00 [hci0] 13.900426 (...) > ACL Data RX: Handle 200 flags 0x00 dlen 1033 #32 [hci0] 14.273106 invalid packet size (12 != 1033) 08 00 01 00 02 01 04 00 01 10 ff ff ............ > ACL Data RX: Handle 200 flags 0x00 dlen 1547 #33 [hci0] 14.273561 invalid packet size (14 != 1547) 0a 00 01 00 04 01 06 00 40 00 00 00 00 00 ........@..... > ACL Data RX: Handle 200 flags 0x00 dlen 2061 #34 [hci0] 14.274390 invalid packet size (16 != 2061) 0c 00 01 00 04 01 08 00 40 00 00 00 00 00 00 04 ........@....... > ACL Data RX: Handle 200 flags 0x00 dlen 2061 #35 [hci0] 14.274932 invalid packet size (16 != 2061) 0c 00 01 00 04 01 08 00 40 00 00 00 07 00 03 00 ........@....... = bluetoothd: Bluetooth daemon 5.43 14.401828 > ACL Data RX: Handle 200 flags 0x00 dlen 1033 #36 [hci0] 14.275753 invalid packet size (12 != 1033) 08 00 01 00 04 01 04 00 40 00 00 00 ........@... Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Diffstat (limited to 'net/bluetooth/l2cap_core.c')
-rw-r--r--net/bluetooth/l2cap_core.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 9c24947aa41e..9fdede5fe71c 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4453,7 +4453,8 @@ static inline int l2cap_config_req(struct l2cap_conn *conn,
chan->ident = cmd->ident;
l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp);
- chan->num_conf_rsp++;
+ if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP)
+ chan->num_conf_rsp++;
/* Reset config buffer. */
chan->conf_len = 0;