From: Zhang Hongtao <zhanghongtao35@huawei.com> mainline inclusion from mainline-v6.18 commit 79a2d4678ba90bdba577dc3af88cc900d6dcd5ee category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13304 CVE: CVE-2025-68304 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't ensure hci_conn* is not concurrently modified/deleted. This locking appears to be leftover from before conn_hash started using RCU commit bf4c63252490b ("Bluetooth: convert conn hash to RCU") and not clear if it had purpose since then. Currently, there are code paths that delete hci_conn* from elsewhere than the ordered hdev->workqueue where the RX work runs in. E.g. commit 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") introduced some of these, and there probably were a few others before it. It's better to do the locking so that even if these run concurrently no UAF is possible. Move the lookup of hci_conn and associated socket-specific conn to protocol recv handlers, and do them within a single critical section to cover hci_conn* usage and lookup. syzkaller has reported a crash that appears to be this issue: [Task hdev->workqueue] [Task 2] hci_disconnect_all_sync l2cap_recv_acldata(hcon) hci_conn_get(hcon) hci_abort_conn_sync(hcon) hci_dev_lock hci_dev_lock hci_conn_del(hcon) v-------------------------------- hci_dev_unlock hci_conn_put(hcon) conn = hcon->l2cap_data (UAF) Fixes: 5af1f84ed13a ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync") Reported-by: syzbot+d32d77220b92eddd89ad@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d32d77220b92eddd89ad Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Conflicts: net/bluetooth/hci_core.c, net/bluetooth/iso.c, net/bluetooth/sco.c, include/net/bluetooth/hci_core.h [conflicts due to not mergered 59437cbb5781227567dec226aaa88c66a09ccc5a ("Bluetooth: hci_core: Fix not checking skb length on hci_scodata_packet")] Signed-off-by: Zhang Hongtao<zhanghongtao35@huawei.com> --- include/net/bluetooth/hci_core.h | 20 +++++--- net/bluetooth/hci_core.c | 78 ++++++++++++-------------------- net/bluetooth/iso.c | 46 ++++++++++++++++--- net/bluetooth/l2cap_core.c | 23 ++++++++-- net/bluetooth/sco.c | 49 ++++++++++++++++---- 5 files changed, 142 insertions(+), 74 deletions(-) diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index 8b60ccdccdc9..3c653208c911 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -832,11 +832,12 @@ extern struct mutex hci_cb_list_lock; /* ----- HCI interface to upper protocols ----- */ int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr); int l2cap_disconn_ind(struct hci_conn *hcon); -void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags); +int l2cap_recv_acldata(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, + u16 flags); #if IS_ENABLED(CONFIG_BT_BREDR) int sco_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags); -void sco_recv_scodata(struct hci_conn *hcon, struct sk_buff *skb); +int sco_recv_scodata(struct hci_dev *hdev, u16 handle, struct sk_buff *skb); #else static inline int sco_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags) @@ -844,23 +845,30 @@ static inline int sco_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, return 0; } -static inline void sco_recv_scodata(struct hci_conn *hcon, struct sk_buff *skb) +static inline int sco_recv_scodata(struct hci_dev *hdev, u16 handle, + struct sk_buff *skb) { + kfree_skb(skb); + return -ENOENT; } #endif #if IS_ENABLED(CONFIG_BT_LE) int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags); -void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags); +int iso_recv(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, + u16 flags); #else static inline int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags) { return 0; } -static inline void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, - u16 flags) + +static inline int iso_recv(struct hci_dev *hdev, u16 handle, + struct sk_buff *skb, u16 flags) { + kfree_skb(skb); + return -ENOENT; } #endif diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index c5e3ae5ddf42..e876875d0dc0 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -3735,13 +3735,14 @@ static void hci_tx_work(struct work_struct *work) static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb) { struct hci_acl_hdr *hdr; - struct hci_conn *conn; __u16 handle, flags; + int err; hdr = skb_pull_data(skb, sizeof(*hdr)); if (!hdr) { bt_dev_err(hdev, "ACL packet too small"); - goto drop; + kfree_skb(skb); + return; } handle = __le16_to_cpu(hdr->handle); @@ -3753,33 +3754,28 @@ static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb) hdev->stat.acl_rx++; - hci_dev_lock(hdev); - conn = hci_conn_hash_lookup_handle(hdev, handle); - hci_dev_unlock(hdev); - - if (conn) { - hci_conn_enter_active_mode(conn, BT_POWER_FORCE_ACTIVE_OFF); - - /* Send to upper protocol */ - l2cap_recv_acldata(conn, skb, flags); - return; - } else { + err = l2cap_recv_acldata(hdev, handle, skb, flags); + if (err == -ENOENT) bt_dev_err(hdev, "ACL packet for unknown connection handle %d", handle); - } - -drop: - kfree_skb(skb); + else if (err) + bt_dev_dbg(hdev, "ACL packet recv for handle %d failed: %d", + handle, err); } /* SCO data packet */ static void hci_scodata_packet(struct hci_dev *hdev, struct sk_buff *skb) { - struct hci_sco_hdr *hdr = (void *) skb->data; - struct hci_conn *conn; + struct hci_sco_hdr *hdr; __u16 handle, flags; + int err; - skb_pull(skb, HCI_SCO_HDR_SIZE); + hdr = skb_pull_data(skb, sizeof(*hdr)); + if (!hdr) { + bt_dev_err(hdev, "SCO packet too small"); + kfree_skb(skb); + return; + } handle = __le16_to_cpu(hdr->handle); flags = hci_flags(handle); @@ -3790,33 +3786,28 @@ static void hci_scodata_packet(struct hci_dev *hdev, struct sk_buff *skb) hdev->stat.sco_rx++; - hci_dev_lock(hdev); - conn = hci_conn_hash_lookup_handle(hdev, handle); - hci_dev_unlock(hdev); + hci_skb_pkt_status(skb) = flags & 0x03; - if (conn) { - /* Send to upper protocol */ - hci_skb_pkt_status(skb) = flags & 0x03; - sco_recv_scodata(conn, skb); - return; - } else { + err = sco_recv_scodata(hdev, handle, skb); + if (err == -ENOENT) bt_dev_err_ratelimited(hdev, "SCO packet for unknown connection handle %d", handle); - } - - kfree_skb(skb); + else if (err) + bt_dev_dbg(hdev, "SCO packet recv for handle %d failed: %d", + handle, err); } static void hci_isodata_packet(struct hci_dev *hdev, struct sk_buff *skb) { struct hci_iso_hdr *hdr; - struct hci_conn *conn; __u16 handle, flags; + int err; hdr = skb_pull_data(skb, sizeof(*hdr)); if (!hdr) { bt_dev_err(hdev, "ISO packet too small"); - goto drop; + kfree_skb(skb); + return; } handle = __le16_to_cpu(hdr->handle); @@ -3826,22 +3817,13 @@ static void hci_isodata_packet(struct hci_dev *hdev, struct sk_buff *skb) bt_dev_dbg(hdev, "len %d handle 0x%4.4x flags 0x%4.4x", skb->len, handle, flags); - hci_dev_lock(hdev); - conn = hci_conn_hash_lookup_handle(hdev, handle); - hci_dev_unlock(hdev); - - if (!conn) { + err = iso_recv(hdev, handle, skb, flags); + if (err == -ENOENT) bt_dev_err(hdev, "ISO packet for unknown connection handle %d", handle); - goto drop; - } - - /* Send to upper protocol */ - iso_recv(conn, skb, flags); - return; - -drop: - kfree_skb(skb); + else if (err) + bt_dev_dbg(hdev, "ISO packet recv for handle %d failed: %d", + handle, err); } static bool hci_req_is_complete(struct hci_dev *hdev) diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c index be71082d9eaf..1b740aba5b65 100644 --- a/net/bluetooth/iso.c +++ b/net/bluetooth/iso.c @@ -36,6 +36,20 @@ struct iso_conn { __u16 tx_sn; }; +static struct iso_conn *iso_conn_hold_unless_zero(struct iso_conn *conn) +{ + /* reuse struct hcon's ref_cnt and cooresponding infrastructure*/ + if (conn && conn->hcon && atomic_inc_not_zero(&conn->hcon->refcnt)) + return conn; + return NULL; +} + +static void iso_conn_put(struct iso_conn *conn) +{ + if (conn && conn->hcon) + hci_conn_put(conn->hcon); +} + #define iso_conn_lock(c) spin_lock(&(c)->lock) #define iso_conn_unlock(c) spin_unlock(&(c)->lock) @@ -1987,13 +2001,30 @@ static void iso_disconn_cfm(struct hci_conn *hcon, __u8 reason) iso_conn_del(hcon, bt_to_errno(reason)); } -void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) +int iso_recv(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, u16 flags) { - struct iso_conn *conn = hcon->iso_data; + struct hci_conn *hcon; + struct iso_conn *conn; __u16 pb, ts, len; - if (!conn) - goto drop; + hci_dev_lock(hdev); + + hcon = hci_conn_hash_lookup_handle(hdev, handle); + if (!hcon) { + hci_dev_unlock(hdev); + kfree_skb(skb); + return -ENOENT; + } + + conn = iso_conn_hold_unless_zero(hcon->iso_data); + hcon = NULL; + + hci_dev_unlock(hdev); + + if (!conn) { + kfree_skb(skb); + return -EINVAL; + } pb = hci_iso_flags_pb(flags); ts = hci_iso_flags_ts(flags); @@ -2043,7 +2074,7 @@ void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) /* Complete frame received */ hci_skb_pkt_status(skb) = flags & 0x03; iso_recv_frame(conn, skb); - return; + goto done; } if (pb == ISO_SINGLE) { @@ -2091,7 +2122,7 @@ void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len), skb->len); conn->rx_len -= skb->len; - return; + break; case ISO_END: skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len), @@ -2113,6 +2144,9 @@ void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) drop: kfree_skb(skb); +done: + iso_conn_put(conn); + return 0; } static struct hci_cb iso_cb = { diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 41ed98f670d5..2f9d6238f413 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -7453,13 +7453,24 @@ struct l2cap_conn *l2cap_conn_hold_unless_zero(struct l2cap_conn *c) return c; } -void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) +int l2cap_recv_acldata(struct hci_dev *hdev, u16 handle, + struct sk_buff *skb, u16 flags) { + struct hci_conn *hcon; struct l2cap_conn *conn; int len; - /* Lock hdev to access l2cap_data to avoid race with l2cap_conn_del */ - hci_dev_lock(hcon->hdev); + /* Lock hdev for hci_conn, and race on l2cap_data vs. l2cap_conn_del */ + hci_dev_lock(hdev); + + hcon = hci_conn_hash_lookup_handle(hdev, handle); + if (!hcon) { + hci_dev_unlock(hdev); + kfree_skb(skb); + return -ENOENT; + } + + hci_conn_enter_active_mode(hcon, BT_POWER_FORCE_ACTIVE_OFF); conn = hcon->l2cap_data; @@ -7467,12 +7478,13 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) conn = l2cap_conn_add(hcon); conn = l2cap_conn_hold_unless_zero(conn); + hcon = NULL; - hci_dev_unlock(hcon->hdev); + hci_dev_unlock(hdev); if (!conn) { kfree_skb(skb); - return; + return -EINVAL; } BT_DBG("conn %p len %u flags 0x%x", conn, skb->len, flags); @@ -7586,6 +7598,7 @@ void l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 flags) unlock: mutex_unlock(&conn->lock); l2cap_conn_put(conn); + return 0; } static struct hci_cb l2cap_cb = { diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index 64d4d57c7033..4e11ab5384cc 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -53,6 +53,20 @@ struct sco_conn { unsigned int mtu; }; +static struct sco_conn *sco_conn_hold_unless_zero(struct sco_conn *conn) +{ + if (conn && conn->hcon && atomic_inc_not_zero(&conn->hcon->refcnt)) + return conn; + + return NULL; +} + +static void sco_conn_put(struct sco_conn *conn) +{ + if (conn && conn->hcon) + hci_conn_put(conn->hcon); +} + #define sco_conn_lock(c) spin_lock(&c->lock) #define sco_conn_unlock(c) spin_unlock(&c->lock) @@ -1380,22 +1394,39 @@ static void sco_disconn_cfm(struct hci_conn *hcon, __u8 reason) sco_conn_del(hcon, bt_to_errno(reason)); } -void sco_recv_scodata(struct hci_conn *hcon, struct sk_buff *skb) +int sco_recv_scodata(struct hci_dev *hdev, u16 handle, struct sk_buff *skb) { - struct sco_conn *conn = hcon->sco_data; + struct hci_conn *hcon; + struct sco_conn *conn; - if (!conn) - goto drop; + hci_dev_lock(hdev); + + hcon = hci_conn_hash_lookup_handle(hdev, handle); + if (!hcon) { + hci_dev_unlock(hdev); + kfree_skb(skb); + return -ENOENT; + } + + conn = sco_conn_hold_unless_zero(hcon->sco_data); + hcon = NULL; + + hci_dev_unlock(hdev); + + if (!conn) { + kfree_skb(skb); + return -EINVAL; + } BT_DBG("conn %p len %u", conn, skb->len); - if (skb->len) { + if (skb->len) sco_recv_frame(conn, skb); - return; - } + else + kfree_skb(skb); -drop: - kfree_skb(skb); + sco_conn_put(conn); + return 0; } static struct hci_cb sco_cb = { -- 2.34.1