6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: HyeongJun An <redacted>
commit 4beb198bc59b242404a47c21990bc84165052c8a upstream.
eir_get_service_data() walks the advertising data for a Service Data
field with a matching UUID. On a mismatch it advances:
eir += dlen;
eir_len -= dlen;
eir_get_data() reports dlen as the field's data length, but the field
spans dlen + 2 bytes once its length and type bytes count, and more
when non-Service-Data fields were skipped to reach it. The pointer
lands correctly on the next field. eir_len does not, and the shortfall
compounds across fields until eir_get_data() reads the length and type
bytes of a "field" past the end of the buffer.
For an ISO broadcast sink that buffer is hcon->le_per_adv_data[], filled
from the periodic advertising reports of a remote broadcaster. A PA
payload packed with mismatching Service Data fields walks off the array
into the rest of struct hci_conn. A drifted field that matches the BAA
UUID puts those bytes in iso_pi(sk)->base, where user space reads them
back with getsockopt(BT_ISO_BASE).
Recompute eir_len from the end of the buffer each iteration.
Fixes: 8f9ae5b3ae80 ("Bluetooth: eir: Add helpers for managing service data")
Cc: <redacted>
Assisted-by: Claude:claude-opus-5
Signed-off-by: HyeongJun An <redacted>
Signed-off-by: Luiz Augusto von Dentz <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bluetooth/eir.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/bluetooth/eir.c
+++ b/net/bluetooth/eir.c
@@ -369,6 +369,7 @@ u8 eir_create_scan_rsp(struct hci_dev *h
void *eir_get_service_data(u8 *eir, size_t eir_len, u16 uuid, size_t *len)
{
+ const u8 *eir_end = eir + eir_len;
size_t dlen;
while ((eir = eir_get_data(eir, eir_len, EIR_SERVICE_DATA, &dlen))) {@@ -381,7 +382,7 @@ void *eir_get_service_data(u8 *eir, size
}
eir += dlen;
- eir_len -= dlen;
+ eir_len = eir_end - eir;
}
return NULL;