isdn/capi: prevent index overrun from command_2_index()
authorTilman Schmidt <tilman@imap.cc>
Sat, 11 Oct 2014 11:46:30 +0000 (13:46 +0200)
committerDavid S. Miller <davem@davemloft.net>
Tue, 14 Oct 2014 19:05:34 +0000 (15:05 -0400)
commit5362247a42e18ef74e698bb23575c272f8e35375
tree554176a9ed7964f711456c7dd41427b2bf8dc2dd
parent9ea8aa8d5087529210553114b7bc4bf4374ace8f
isdn/capi: prevent index overrun from command_2_index()

The result of the function command_2_index() is used to index two
arrays mnames[] and cpars[] with max. index 0x4e but in its current
form that function can produce results up to 3*(0x9+0x9)+0x7f =
0xb5.
Fix by clamping all result values potentially overrunning the arrays
to zero which is already handled as an invalid value.

Re-spotted with Coverity.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/isdn/capi/capiutil.c