Re: [PATCH] ax25: unsigned cannot be less than 0 in ax25_ctl_ioctl()
From: Roel Kluin <hidden>
Date: 2009-10-14 15:17:43
Also in:
linux-hams
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2009-10-10 · [PATCH] ax25: unsigned cannot be less than 0 in ax25_ctl_ioctl() · Roel Kluin <hidden>
struct ax25_ctl_struct member `arg' is unsigned and cannot be less than 0. Signed-off-by: Roel Kluin <redacted> --- Op 12-10-09 23:58, Kevin Dawson schreef:
quoted
quoted
tmp_arg=ax25_ctl.arg * HZ; if (arg == 0 || arg > ULONG_MAX ) goto einval_put;I'm not sure, I think this would only work if we made `arg' an unsigned long long.That depends on the possible values of ax25_ctl.arg.quoted
+ if (ax25_ctl.arg * HZ > ULONG_MAX && ax25_ctl.cmd != AX25_KILL) + return -EINVAL;Why the need to change arg before comparing it with a constant? Let the compiler do the work: if (ax25_ctl.arg > ULONG_MAX / HZ && ...
Ok, How about this then?
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index f454607..d923ac4 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c@@ -369,6 +369,9 @@ static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg) if (ax25_ctl.digi_count > AX25_MAX_DIGIS) return -EINVAL; + if (ax25_ctl.arg > ULONG_MAX / HZ && ax25_ctl.cmd != AX25_KILL) + return -EINVAL; + digi.ndigi = ax25_ctl.digi_count; for (k = 0; k < digi.ndigi; k++) digi.calls[k] = ax25_ctl.digi_addr[k];
@@ -418,14 +421,10 @@ static int ax25_ctl_ioctl(const unsigned int cmd, void __user *arg) break; case AX25_T3: - if (ax25_ctl.arg < 0) - goto einval_put; ax25->t3 = ax25_ctl.arg * HZ; break; case AX25_IDLE: - if (ax25_ctl.arg < 0) - goto einval_put; ax25->idle = ax25_ctl.arg * 60 * HZ; break;