linux/net/bluetooth/smp.h
Matias Karhumaa cb28c306b9 Bluetooth: SMP: fix crash in unpairing
In case unpair_device() was called through mgmt interface at the same time
when pairing was in progress, Bluetooth kernel module crash was seen.

[  600.351225] general protection fault: 0000 [#1] SMP PTI
[  600.351235] CPU: 1 PID: 11096 Comm: btmgmt Tainted: G           OE     4.19.0-rc1+ #1
[  600.351238] Hardware name: Dell Inc. Latitude E5440/08RCYC, BIOS A18 05/14/2017
[  600.351272] RIP: 0010:smp_chan_destroy.isra.10+0xce/0x2c0 [bluetooth]
[  600.351276] Code: c0 0f 84 b4 01 00 00 80 78 28 04 0f 84 53 01 00 00 4d 85 ed 0f 85 ab 00 00 00 48 8b 08 48 8b 50 08 be 10 00 00 00 48 89 51 08 <48> 89 0a 48 b9 00 02 00 00 00 00 ad de 48 89 48 08 48 8b 83 00 01
[  600.351279] RSP: 0018:ffffa9be839b3b50 EFLAGS: 00010246
[  600.351282] RAX: ffff9c999ac565a0 RBX: ffff9c9996e98c00 RCX: ffff9c999aa28b60
[  600.351285] RDX: dead000000000200 RSI: 0000000000000010 RDI: ffff9c999e403500
[  600.351287] RBP: ffffa9be839b3b70 R08: 0000000000000000 R09: ffffffff92a25c00
[  600.351290] R10: ffffa9be839b3ae8 R11: 0000000000000001 R12: ffff9c995375b800
[  600.351292] R13: 0000000000000000 R14: ffff9c99619a5000 R15: ffff9c9962a01c00
[  600.351295] FS:  00007fb2be27c700(0000) GS:ffff9c999e880000(0000) knlGS:0000000000000000
[  600.351298] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  600.351300] CR2: 00007fb2bdadbad0 CR3: 000000041c328001 CR4: 00000000001606e0
[  600.351302] Call Trace:
[  600.351325]  smp_failure+0x4f/0x70 [bluetooth]
[  600.351345]  smp_cancel_pairing+0x74/0x80 [bluetooth]
[  600.351370]  unpair_device+0x1c1/0x330 [bluetooth]
[  600.351399]  hci_sock_sendmsg+0x960/0x9f0 [bluetooth]
[  600.351409]  ? apparmor_socket_sendmsg+0x1e/0x20
[  600.351417]  sock_sendmsg+0x3e/0x50
[  600.351422]  sock_write_iter+0x85/0xf0
[  600.351429]  do_iter_readv_writev+0x12b/0x1b0
[  600.351434]  do_iter_write+0x87/0x1a0
[  600.351439]  vfs_writev+0x98/0x110
[  600.351443]  ? ep_poll+0x16d/0x3d0
[  600.351447]  ? ep_modify+0x73/0x170
[  600.351451]  do_writev+0x61/0xf0
[  600.351455]  ? do_writev+0x61/0xf0
[  600.351460]  __x64_sys_writev+0x1c/0x20
[  600.351465]  do_syscall_64+0x5a/0x110
[  600.351471]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  600.351474] RIP: 0033:0x7fb2bdb62fe0
[  600.351477] Code: 73 01 c3 48 8b 0d b8 6e 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 69 c7 2c 00 00 75 10 b8 14 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 de 80 01 00 48 89 04 24
[  600.351479] RSP: 002b:00007ffe062cb8f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
[  600.351484] RAX: ffffffffffffffda RBX: 000000000255b3d0 RCX: 00007fb2bdb62fe0
[  600.351487] RDX: 0000000000000001 RSI: 00007ffe062cb920 RDI: 0000000000000004
[  600.351490] RBP: 00007ffe062cb920 R08: 000000000255bd80 R09: 0000000000000000
[  600.351494] R10: 0000000000000353 R11: 0000000000000246 R12: 0000000000000001
[  600.351497] R13: 00007ffe062cbbe0 R14: 0000000000000000 R15: 0000000000000000
[  600.351501] Modules linked in: algif_hash algif_skcipher af_alg cmac ipt_MASQUERADE nf_conntrack_netlink nfnetlink xfrm_user xfrm_algo iptable_nat nf_nat_ipv4 xt_addrtype iptable_filter ip_tables xt_conntrack x_tables nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c br_netfilter bridge stp llc overlay arc4 nls_iso8859_1 dm_crypt intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp dell_laptop kvm_intel crct10dif_pclmul dell_smm_hwmon crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper intel_cstate intel_rapl_perf uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev media hid_multitouch input_leds joydev serio_raw dell_wmi snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic dell_smbios dcdbas sparse_keymap
[  600.351569]  snd_hda_intel btusb snd_hda_codec btrtl btbcm btintel snd_hda_core bluetooth(OE) snd_hwdep snd_pcm iwlmvm ecdh_generic wmi_bmof dell_wmi_descriptor snd_seq_midi mac80211 snd_seq_midi_event lpc_ich iwlwifi snd_rawmidi snd_seq snd_seq_device snd_timer cfg80211 snd soundcore mei_me mei dell_rbtn dell_smo8800 mac_hid parport_pc ppdev lp parport autofs4 hid_generic usbhid hid i915 nouveau kvmgt vfio_mdev mdev vfio_iommu_type1 vfio kvm irqbypass i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect sysimgblt mxm_wmi psmouse ahci sdhci_pci cqhci libahci fb_sys_fops sdhci drm e1000e video wmi
[  600.351637] ---[ end trace e49e9f1df09c94fb ]---
[  600.351664] RIP: 0010:smp_chan_destroy.isra.10+0xce/0x2c0 [bluetooth]
[  600.351666] Code: c0 0f 84 b4 01 00 00 80 78 28 04 0f 84 53 01 00 00 4d 85 ed 0f 85 ab 00 00 00 48 8b 08 48 8b 50 08 be 10 00 00 00 48 89 51 08 <48> 89 0a 48 b9 00 02 00 00 00 00 ad de 48 89 48 08 48 8b 83 00 01
[  600.351669] RSP: 0018:ffffa9be839b3b50 EFLAGS: 00010246
[  600.351672] RAX: ffff9c999ac565a0 RBX: ffff9c9996e98c00 RCX: ffff9c999aa28b60
[  600.351674] RDX: dead000000000200 RSI: 0000000000000010 RDI: ffff9c999e403500
[  600.351676] RBP: ffffa9be839b3b70 R08: 0000000000000000 R09: ffffffff92a25c00
[  600.351679] R10: ffffa9be839b3ae8 R11: 0000000000000001 R12: ffff9c995375b800
[  600.351681] R13: 0000000000000000 R14: ffff9c99619a5000 R15: ffff9c9962a01c00
[  600.351684] FS:  00007fb2be27c700(0000) GS:ffff9c999e880000(0000) knlGS:0000000000000000
[  600.351686] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  600.351689] CR2: 00007fb2bdadbad0 CR3: 000000041c328001 CR4: 00000000001606e0

Crash happened because list_del_rcu() was called twice for smp->ltk. This
was possible if unpair_device was called right after ltk was generated
but before keys were distributed.

In this commit smp_cancel_pairing was refactored to cancel pairing if it
is in progress and otherwise just removes keys. Once keys are removed from
rcu list, pointers to smp context's keys are set to NULL to make sure
removed list items are not accessed later.

This commit also adjusts the functionality of mgmt unpair_device() little
bit. Previously pairing was canceled only if pairing was in state that
keys were already generated. With this commit unpair_device() cancels
pairing already in earlier states.

Bug was found by fuzzing kernel SMP implementation using Synopsys
Defensics.

Reported-by: Pekka Oikarainen <pekka.oikarainen@synopsys.com>
Signed-off-by: Matias Karhumaa <matias.karhumaa@gmail.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
2018-09-26 12:39:32 +03:00

213 lines
5.0 KiB
C

/*
BlueZ - Bluetooth protocol stack for Linux
Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation;
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
SOFTWARE IS DISCLAIMED.
*/
#ifndef __SMP_H
#define __SMP_H
struct smp_command_hdr {
__u8 code;
} __packed;
#define SMP_CMD_PAIRING_REQ 0x01
#define SMP_CMD_PAIRING_RSP 0x02
struct smp_cmd_pairing {
__u8 io_capability;
__u8 oob_flag;
__u8 auth_req;
__u8 max_key_size;
__u8 init_key_dist;
__u8 resp_key_dist;
} __packed;
#define SMP_IO_DISPLAY_ONLY 0x00
#define SMP_IO_DISPLAY_YESNO 0x01
#define SMP_IO_KEYBOARD_ONLY 0x02
#define SMP_IO_NO_INPUT_OUTPUT 0x03
#define SMP_IO_KEYBOARD_DISPLAY 0x04
#define SMP_OOB_NOT_PRESENT 0x00
#define SMP_OOB_PRESENT 0x01
#define SMP_DIST_ENC_KEY 0x01
#define SMP_DIST_ID_KEY 0x02
#define SMP_DIST_SIGN 0x04
#define SMP_DIST_LINK_KEY 0x08
#define SMP_AUTH_NONE 0x00
#define SMP_AUTH_BONDING 0x01
#define SMP_AUTH_MITM 0x04
#define SMP_AUTH_SC 0x08
#define SMP_AUTH_KEYPRESS 0x10
#define SMP_AUTH_CT2 0x20
#define SMP_CMD_PAIRING_CONFIRM 0x03
struct smp_cmd_pairing_confirm {
__u8 confirm_val[16];
} __packed;
#define SMP_CMD_PAIRING_RANDOM 0x04
struct smp_cmd_pairing_random {
__u8 rand_val[16];
} __packed;
#define SMP_CMD_PAIRING_FAIL 0x05
struct smp_cmd_pairing_fail {
__u8 reason;
} __packed;
#define SMP_CMD_ENCRYPT_INFO 0x06
struct smp_cmd_encrypt_info {
__u8 ltk[16];
} __packed;
#define SMP_CMD_MASTER_IDENT 0x07
struct smp_cmd_master_ident {
__le16 ediv;
__le64 rand;
} __packed;
#define SMP_CMD_IDENT_INFO 0x08
struct smp_cmd_ident_info {
__u8 irk[16];
} __packed;
#define SMP_CMD_IDENT_ADDR_INFO 0x09
struct smp_cmd_ident_addr_info {
__u8 addr_type;
bdaddr_t bdaddr;
} __packed;
#define SMP_CMD_SIGN_INFO 0x0a
struct smp_cmd_sign_info {
__u8 csrk[16];
} __packed;
#define SMP_CMD_SECURITY_REQ 0x0b
struct smp_cmd_security_req {
__u8 auth_req;
} __packed;
#define SMP_CMD_PUBLIC_KEY 0x0c
struct smp_cmd_public_key {
__u8 x[32];
__u8 y[32];
} __packed;
#define SMP_CMD_DHKEY_CHECK 0x0d
struct smp_cmd_dhkey_check {
__u8 e[16];
} __packed;
#define SMP_CMD_KEYPRESS_NOTIFY 0x0e
struct smp_cmd_keypress_notify {
__u8 value;
} __packed;
#define SMP_CMD_MAX 0x0e
#define SMP_PASSKEY_ENTRY_FAILED 0x01
#define SMP_OOB_NOT_AVAIL 0x02
#define SMP_AUTH_REQUIREMENTS 0x03
#define SMP_CONFIRM_FAILED 0x04
#define SMP_PAIRING_NOTSUPP 0x05
#define SMP_ENC_KEY_SIZE 0x06
#define SMP_CMD_NOTSUPP 0x07
#define SMP_UNSPECIFIED 0x08
#define SMP_REPEATED_ATTEMPTS 0x09
#define SMP_INVALID_PARAMS 0x0a
#define SMP_DHKEY_CHECK_FAILED 0x0b
#define SMP_NUMERIC_COMP_FAILED 0x0c
#define SMP_BREDR_PAIRING_IN_PROGRESS 0x0d
#define SMP_CROSS_TRANSP_NOT_ALLOWED 0x0e
#define SMP_MIN_ENC_KEY_SIZE 7
#define SMP_MAX_ENC_KEY_SIZE 16
/* LTK types used in internal storage (struct smp_ltk) */
enum {
SMP_STK,
SMP_LTK,
SMP_LTK_SLAVE,
SMP_LTK_P256,
SMP_LTK_P256_DEBUG,
};
static inline bool smp_ltk_is_sc(struct smp_ltk *key)
{
switch (key->type) {
case SMP_LTK_P256:
case SMP_LTK_P256_DEBUG:
return true;
}
return false;
}
static inline u8 smp_ltk_sec_level(struct smp_ltk *key)
{
if (key->authenticated) {
if (smp_ltk_is_sc(key))
return BT_SECURITY_FIPS;
else
return BT_SECURITY_HIGH;
}
return BT_SECURITY_MEDIUM;
}
/* Key preferences for smp_sufficient security */
enum smp_key_pref {
SMP_ALLOW_STK,
SMP_USE_LTK,
};
/* SMP Commands */
int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr,
u8 addr_type);
bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level,
enum smp_key_pref key_pref);
int smp_conn_security(struct hci_conn *hcon, __u8 sec_level);
int smp_user_confirm_reply(struct hci_conn *conn, u16 mgmt_op, __le32 passkey);
bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],
const bdaddr_t *bdaddr);
int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa);
int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]);
int smp_register(struct hci_dev *hdev);
void smp_unregister(struct hci_dev *hdev);
#if IS_ENABLED(CONFIG_BT_SELFTEST_SMP)
int bt_selftest_smp(void);
#else
static inline int bt_selftest_smp(void)
{
return 0;
}
#endif
#endif /* __SMP_H */