Commit c4a5af54 authored Nov 23, 2009 by Andrew G. Morgan Committed by James Morris Nov 24, 2009

Silence the existing API for capability version compatibility check.



When libcap, or other libraries attempt to confirm/determine the supported
capability version magic, they generally supply a NULL dataptr to capget().

In this case, while returning the supported/preferred magic (via a
modified header content), the return code of this system call may be 0,
-EINVAL, or -EFAULT.

No libcap code depends on the previous -EINVAL etc. return code, and
all of the above three return codes can accompany a valid (successful)
attempt to determine the requested magic value.

This patch cleans up the system call to return 0, if the call is
successfully being used to determine the supported/preferred capability
magic value.

Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>

parent fe542cf5

kernel/capability.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -169,8 +169,8 @@ SYSCALL_DEFINE2(capget, cap_user_header_t, header, cap_user_data_t, dataptr)
		kernel_cap_t pE, pI, pP;

		ret = cap_validate_magic(header, &tocopy);
		if (ret != 0)
		return ret;
		if ((dataptr == NULL) \|\| (ret != 0))
		return ((dataptr == NULL) && (ret == -EINVAL)) ? 0 : ret;

		if (get_user(pid, &header->pid))
		return -EFAULT;

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