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Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ioports

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From: Christian Krafft
Subject: Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ioports
Date: Wednesday, February 13, 2008 - 10:35 am

sensors_detect crashes kernel on PowerPC, as it pokes directly to memory.
This patch adds a check_legacy_ioports to read_port and write_port.
It will now return ENXIO, instead of oopsing.

Signed-off-by: Christian Krafft <krafft@de.ibm.com>

Index: linux.git/drivers/char/mem.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- linux.git.orig/drivers/char/mem.c
+++ linux.git/drivers/char/mem.c
@@ -566,8 +566,13 @@ static ssize_t read_port(struct file * f
 	char __user *tmp =3D buf;
=20
 	if (!access_ok(VERIFY_WRITE, buf, count))
-		return -EFAULT;=20
+		return -EFAULT;
+
 	while (count-- > 0 && i < 65536) {
+#ifdef CONFIG_PPC_MERGE
+		if (check_legacy_ioport(i))
+			return -ENXIO;
+#endif
 		if (__put_user(inb(i),tmp) < 0)=20
 			return -EFAULT; =20
 		i++;
@@ -585,6 +590,7 @@ static ssize_t write_port(struct file *=20
=20
 	if (!access_ok(VERIFY_READ,buf,count))
 		return -EFAULT;
+
 	while (count-- > 0 && i < 65536) {
 		char c;
 		if (__get_user(c, tmp)) {
@@ -592,6 +598,10 @@ static ssize_t write_port(struct file *=20
 				break;
 			return -EFAULT;=20
 		}
+#ifdef CONFIG_PPC_MERGE
+		if (check_legacy_ioport(i))
+			return -ENXIO;
+#endif
 		outb(c,i);
 		i++;
 		tmp++;


--=20
Mit freundlichen Gruessen,
kind regards,

Christian Krafft
IBM Systems & Technology Group,
Linux Kernel Development
IT Specialist


Vorsitzender des Aufsichtsrats:	Martin Jetter
Geschaeftsfuehrung:		Herbert Kircher
Sitz der Gesellschaft:		Boeblingen
Registriergericht:		Amtsgericht Stuttgart, HRB 243294
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Messages in current thread:
[Patch 0/2] add check_legacy_ioport calls to prevent oops, Christian Krafft, (Wed Feb 13, 10:28 am)
Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ..., Christian Krafft, (Wed Feb 13, 10:35 am)
Re: [Patch 2/2] powerpc: i2c-isa: add access check to lega ..., Christian Krafft, (Wed Feb 13, 10:37 am)
Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ..., Benjamin Herrenschmidt, (Wed Feb 13, 1:42 pm)
Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ..., Arnd Bergmann, (Wed Feb 13, 4:07 pm)
Re: [Patch 2/2] powerpc: i2c-isa: add access check to lega ..., Jean Delvare, (Mon Feb 18, 6:31 am)
Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ..., Jean Delvare, (Mon Feb 18, 1:15 pm)
Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ..., Benjamin Herrenschmidt, (Mon Feb 18, 1:42 pm)
Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ..., Jean Delvare, (Mon Feb 18, 1:58 pm)
Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ..., Arjan van de Ven, (Mon Feb 18, 2:04 pm)
Re: [Patch 0/2] powerpc: avoid userspace poking to legacy ..., Benjamin Herrenschmidt, (Mon Feb 18, 2:05 pm)