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In bnep_rx_frame(), the BNEP_FILTER_NET_TYPE_SET and
BNEP_FILTER_MULTI_ADDR_SET extension header parsing has two bugs:
1) The 2-byte length field is read with *(u16 *)(skb->data + 1), which
performs a native-endian read. The BNEP protocol specifies this field
in big-endian (network byte order), and the same file correctly uses
get_unaligned_be16() for the identical fields in
bnep_ctrl_set_netfilter() and bnep_ctrl_set_mcfilter().
2) The length is multiplied by 2, but unlike BNEP_SETUP_CONN_REQ where
the length byte counts UUID pairs (requiring * 2 for two UUIDs per
entry), the filter extension length field already represents the total
data size in bytes. This is confirmed by bnep_ctrl_set_netfilter()
which reads the same field as a byte count and divides by 4 to get
the number of filter entries.
The bogus * 2 means skb_pull advances twice as far as it should,
either dropping valid data from the next header or causing the pull
to fail entirely when the doubled length exceeds the remaining skb.
Fix by splitting the pull into two steps: first use skb_pull_data() to
safely pull and validate the 3-byte fixed header (ctrl type + length),
then pull the variable-length data using the properly decoded length.
Fixes:
|
||
|---|---|---|
| .. | ||
| bnep.h | ||
| core.c | ||
| Kconfig | ||
| Makefile | ||
| netdev.c | ||
| sock.c | ||