diff options
| author | hkbinbin <hkbinbinbin@gmail.com> | 2026-03-31 08:39:16 +0300 |
|---|---|---|
| committer | Luiz Augusto von Dentz <luiz.von.dentz@intel.com> | 2026-04-01 23:48:28 +0300 |
| commit | bc39a094730ce062fa034a529c93147c096cb488 (patch) | |
| tree | edd0c557a3c6fefc771d49dab16b2f952d83e882 /net | |
| parent | 20756fec2f0108cb88e815941f1ffff88dc286fe (diff) | |
| download | linux-bc39a094730ce062fa034a529c93147c096cb488.tar.xz | |
Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync
hci_le_big_create_sync() uses DEFINE_FLEX to allocate a
struct hci_cp_le_big_create_sync on the stack with room for 0x11 (17)
BIS entries. However, conn->num_bis can hold up to HCI_MAX_ISO_BIS (31)
entries — validated against ISO_MAX_NUM_BIS (0x1f) in the caller
hci_conn_big_create_sync(). When conn->num_bis is between 18 and 31,
the memcpy that copies conn->bis into cp->bis writes up to 14 bytes
past the stack buffer, corrupting adjacent stack memory.
This is trivially reproducible: binding an ISO socket with
bc_num_bis = ISO_MAX_NUM_BIS (31) and calling listen() will
eventually trigger hci_le_big_create_sync() from the HCI command
sync worker, causing a KASAN-detectable stack-out-of-bounds write:
BUG: KASAN: stack-out-of-bounds in hci_le_big_create_sync+0x256/0x3b0
Write of size 31 at addr ffffc90000487b48 by task kworker/u9:0/71
Fix this by changing the DEFINE_FLEX count from the incorrect 0x11 to
HCI_MAX_ISO_BIS, which matches the maximum number of BIS entries that
conn->bis can actually carry.
Fixes: 42ecf1947135 ("Bluetooth: ISO: Do not emit LE BIG Create Sync if previous is pending")
Cc: stable@vger.kernel.org
Signed-off-by: hkbinbin <hkbinbinbin@gmail.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bluetooth/hci_sync.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index ffb0ceda6f7b..919ec275dd23 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -7241,7 +7241,8 @@ static void create_big_complete(struct hci_dev *hdev, void *data, int err) static int hci_le_big_create_sync(struct hci_dev *hdev, void *data) { - DEFINE_FLEX(struct hci_cp_le_big_create_sync, cp, bis, num_bis, 0x11); + DEFINE_FLEX(struct hci_cp_le_big_create_sync, cp, bis, num_bis, + HCI_MAX_ISO_BIS); struct hci_conn *conn = data; struct bt_iso_qos *qos = &conn->iso_qos; int err; |