Messages in this thread | | | Date | Mon, 9 Dec 2002 22:51:59 -0800 | From | carbonated beverage <> | Subject | Re: capable open_port() check wrong for kmem |
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forgot to cc: linux-kernel:
Hi,
On Tue, Dec 10, 2002 at 05:45:09AM +0000, David Wagner wrote: > Read-only access to /dev/kmem is probably enough to get root access > (maybe you can snoop root's password, for instance). This would make > the power of the two capabilities roughly equivalent, so if this is true, > I'm not sure I understand the point of splitting them in two this way.
It's rather annoying and counter-intuitive to have:
crw-r----- 1 root kmem 1, 2 Sep 8 21:56 /dev/kmem
but to have the following code fragment give:
int fd; fd = open("/dev/kmem", O_RDONLY); if(fd == -1) { fprintf(stderr, "Can't open /dev/kmem: %s\n", strerror(errno)); exit(EXIT_FAILURE); }
Can't open /dev/kmem: Operation not permitted
with a user in the kmem group.
Also, the utility I'm writing doesn't need write access, so why give it to the process in the first place?
-- DN Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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