From: Gabriel Laskar <gabriel@lse.epita.fr>
Date: Wed, 23 Sep 2015 08:11:55 +0000 (+0200)
Subject: ioctl: fix ioctl command number decoding in case of conflicts
X-Git-Tag: v4.11~162
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9c4fc3404cff4c58b7c9707c85da9661f87131c7;p=strace

ioctl: fix ioctl command number decoding in case of conflicts

When a command number was decoded through ioctl_decode_command_number(),
there was no check for conflicts with other potential ioctls numbers.

For example:
	ioctl(fd, MCE_GET_RECORD_LEN, &i);
output:
	ioctl(3, MIXER_READ(1), 0x7ffddce74a58) = 0
instead of:
	ioctl(3, MIXER_READ(1) or MCE_GET_RECORD_LEN, 0x7ffee435ce08) = 0

* ioctl.c (SYS_FUNC(ioctl)): Fix ioctl command number decoding
in case of conflicts.
* tests/ioctl.c (main): Add a case for command number conflicts.

Signed-off-by: Gabriel Laskar <gabriel@lse.epita.fr>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
---

diff --git a/ioctl.c b/ioctl.c
index 284828a5..adce9867 100644
--- a/ioctl.c
+++ b/ioctl.c
@@ -277,15 +277,16 @@ SYS_FUNC(ioctl)
 	if (entering(tcp)) {
 		printfd(tcp, tcp->u_arg[0]);
 		tprints(", ");
-		if (!ioctl_decode_command_number(tcp)) {
-			iop = ioctl_lookup(tcp->u_arg[1]);
-			if (iop) {
-				tprints(iop->symbol);
-				while ((iop = ioctl_next_match(iop)))
-					tprintf(" or %s", iop->symbol);
-			} else {
-				ioctl_print_code(tcp->u_arg[1]);
-			}
+		ret = ioctl_decode_command_number(tcp);
+		iop = ioctl_lookup(tcp->u_arg[1]);
+		if (iop) {
+			if (ret)
+				tprints(" or ");
+			tprints(iop->symbol);
+			while ((iop = ioctl_next_match(iop)))
+				tprintf(" or %s", iop->symbol);
+		} else if (!ret) {
+			ioctl_print_code(tcp->u_arg[1]);
 		}
 		ret = ioctl_decode(tcp);
 	} else {
diff --git a/tests/ioctl.c b/tests/ioctl.c
index 7f9b84ce..7882140f 100644
--- a/tests/ioctl.c
+++ b/tests/ioctl.c
@@ -58,6 +58,10 @@ main(void )
 	printf("ioctl(-1, EVIOCGBIT(EV_KEY, 8), %p)"
 	       " = -1 EBADF (Bad file descriptor)\n", &data);
 
+	(void) ioctl(-1, _IOR('M', 13, int), &data);
+	printf("ioctl(-1, MIXER_READ(13) or OTPSELECT, [MTD_OTP_OFF])"
+	       " = -1 EBADF (Bad file descriptor)\n");
+
 	(void) ioctl(-1, _IOR(0xde, 0xad, data), &data);
 	printf("ioctl(-1, _IOC(_IOC_READ, 0xde, 0xad, 0x08), %p)"
 	       " = -1 EBADF (Bad file descriptor)\n", &data);