From 5362247a42e18ef74e698bb23575c272f8e35375 Mon Sep 17 00:00:00 2001 From: Tilman Schmidt <tilman@imap.cc> Date: Sat, 11 Oct 2014 13:46:30 +0200 Subject: [PATCH] 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 | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/isdn/capi/capiutil.c b/drivers/isdn/capi/capiutil.c index 4073d1684d07e..b501d76209f02 100644 --- a/drivers/isdn/capi/capiutil.c +++ b/drivers/isdn/capi/capiutil.c @@ -207,6 +207,8 @@ static unsigned command_2_index(unsigned c, unsigned sc) c = 0x9 + (c & 0x0f); else if (c == 0x41) c = 0x9 + 0x1; + if (c > 0x18) + c = 0x00; return (sc & 3) * (0x9 + 0x9) + c; } -- 2.30.2