From: Pauli Virtanen <pav@iki.fi> mainline inclusion from mainline-v6.18-rc4 commit e8785404de06a69d89dcdd1e9a0b6ea42dc6d327 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/7954 CVE: CVE-2025-39981 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- There is a BUG: KASAN: stack-out-of-bounds in set_mesh_sync due to memcpy from badly declared on-stack flexible array. Another crash is in set_mesh_complete() due to double list_del via mgmt_pending_valid + mgmt_pending_remove. Use DEFINE_FLEX to declare the flexible array right, and don't memcpy outside bounds. As mgmt_pending_valid removes the cmd from list, use mgmt_pending_free, and also report status on error. Fixes: 302a1f674c00d ("Bluetooth: MGMT: Fix possible UAFs") Signed-off-by: Pauli Virtanen <pav@iki.fi> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> --- include/net/bluetooth/mgmt.h | 2 +- net/bluetooth/mgmt.c | 26 +++++++++++++++----------- 2 files changed, 16 insertions(+), 12 deletions(-) diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h index e083f0fa0113..6cf97ad15a4c 100644 --- a/include/net/bluetooth/mgmt.h +++ b/include/net/bluetooth/mgmt.h @@ -847,7 +847,7 @@ struct mgmt_cp_set_mesh { __le16 window; __le16 period; __u8 num_ad_types; - __u8 ad_types[]; + __u8 ad_types[] __counted_by(num_ad_types); } __packed; #define MGMT_SET_MESH_RECEIVER_SIZE 6 diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index ed7fa1148b8f..50945738f094 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -2163,19 +2163,24 @@ static void set_mesh_complete(struct hci_dev *hdev, void *data, int err) sk = cmd->sk; if (status) { + mgmt_cmd_status(cmd->sk, hdev->id, MGMT_OP_SET_MESH_RECEIVER, + status); mgmt_pending_foreach(MGMT_OP_SET_MESH_RECEIVER, hdev, true, cmd_status_rsp, &status); - return; + goto done; } - mgmt_pending_remove(cmd); mgmt_cmd_complete(sk, hdev->id, MGMT_OP_SET_MESH_RECEIVER, 0, NULL, 0); + +done: + mgmt_pending_free(cmd); } static int set_mesh_sync(struct hci_dev *hdev, void *data) { struct mgmt_pending_cmd *cmd = data; - struct mgmt_cp_set_mesh cp; + DEFINE_FLEX(struct mgmt_cp_set_mesh, cp, ad_types, num_ad_types, + sizeof(hdev->mesh_ad_types)); size_t len; mutex_lock(&hdev->mgmt_pending_lock); @@ -2185,27 +2190,26 @@ static int set_mesh_sync(struct hci_dev *hdev, void *data) return -ECANCELED; } - memcpy(&cp, cmd->param, sizeof(cp)); + len = cmd->param_len; + memcpy(cp, cmd->param, min(__struct_size(cp), len)); mutex_unlock(&hdev->mgmt_pending_lock); - len = cmd->param_len; - memset(hdev->mesh_ad_types, 0, sizeof(hdev->mesh_ad_types)); - if (cp.enable) + if (cp->enable) hci_dev_set_flag(hdev, HCI_MESH); else hci_dev_clear_flag(hdev, HCI_MESH); - hdev->le_scan_interval = __le16_to_cpu(cp.period); - hdev->le_scan_window = __le16_to_cpu(cp.window); + hdev->le_scan_interval = __le16_to_cpu(cp->period); + hdev->le_scan_window = __le16_to_cpu(cp->window); - len -= sizeof(cp); + len -= sizeof(struct mgmt_cp_set_mesh); /* If filters don't fit, forward all adv pkts */ if (len <= sizeof(hdev->mesh_ad_types)) - memcpy(hdev->mesh_ad_types, cp.ad_types, len); + memcpy(hdev->mesh_ad_types, cp->ad_types, len); hci_update_passive_scan_sync(hdev); return 0; -- 2.43.0