host/ble_l2cap_coc: coc_rx.sdus index should not exceed BLE_L2CAP_SDU_BUFF_CNT #1567
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@jrotkiewicz PTAL. AFAIK if mynewt-nimble/nimble/host/src/ble_l2cap_coc.c Lines 606 to 610 in ef0fb14 But maybe I'm missing something :) I'm sure of a crash though |
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This was caught while testing #845 |
KKopyscinski
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As discussed offline, |
rymanluk
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Jul 25, 2023
nimble/host/src/ble_l2cap_coc.c
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| @@ -341,7 +341,8 @@ ble_l2cap_coc_chan_alloc(struct ble_hs_conn *conn, uint16_t psm, uint16_t mtu, | |||
| chan->coc_rx.sdus[i] = NULL; | |||
| } | |||
| chan->coc_rx.current_sdu_idx = 0; | |||
| chan->coc_rx.next_sdu_alloc_idx = chan->coc_rx.sdus[0] == NULL ? 0 : 1; | |||
| chan->coc_rx.next_sdu_alloc_idx = chan->coc_rx.sdus[0] == NULL || | |||
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Thanks.
technically it is ok, but lets try to make it look nicer using if () Ok ?
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ble_l2cap_coc_chan_alloc can be called with *sdu_rx = NULL - in that case, with previous fix, we would set next_sdu_alloc_idx = 1 where it should be 0. Fixed this with simple if case for BLE_L2CAP_SDU_BUFF_CNT == 1
…_BUFF_CNT Multiple calls to `ble_l2cap_coc_recv_ready` with `BLE_L2CAP_SDU_BUFF_CNT == 1` will lead to assigning coc_rx.sdus outside array range - so this will (most likely) overwrite rest of stucture. This will lead to either undefined behavior or crash when structure members are accessed.
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LGTM |
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Multiple calls to
ble_l2cap_coc_recv_readywithBLE_L2CAP_SDU_BUFF_CNT == 1will lead to assigning coc_rx.sdus outside array range - so this will (most likely) overwrite rest of stucture. This will lead to either undefined behavior or crash when structure members are accessed.