AX.25: Prevent out-of-bounds read in ax25_sendmsg()
authorPeilin Ye <yepeilin.cs@gmail.com>
Wed, 22 Jul 2020 16:05:12 +0000 (12:05 -0400)
committerDavid S. Miller <davem@davemloft.net>
Thu, 23 Jul 2020 01:06:49 +0000 (18:06 -0700)
commit8885bb0621f01a6c82be60a91e5fc0f6e2f71186
treec91120c4f5a39c568f95e4f48a9098cb285c2678
parentf659173364c64d3276b8aba62368e7e732fab309
AX.25: Prevent out-of-bounds read in ax25_sendmsg()

Checks on `addr_len` and `usax->sax25_ndigis` are insufficient.
ax25_sendmsg() can go out of bounds when `usax->sax25_ndigis` equals to 7
or 8. Fix it.

It is safe to remove `usax->sax25_ndigis > AX25_MAX_DIGIS`, since
`addr_len` is guaranteed to be less than or equal to
`sizeof(struct full_sockaddr_ax25)`

Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ax25/af_ax25.c