Commit c80567c8 authored Feb 27, 2016 by Al Viro

do_last(): don't let a bogus return value from ->open() et.al. to confuse us



... into returning a positive to path_openat(), which would interpret that
as "symlink had been encountered" and proceed to corrupt memory, etc.
It can only happen due to a bug in some ->open() instance or in some LSM
hook, etc., so we report any such event *and* make sure it doesn't trick
us into further unpleasantness.

Cc: stable@vger.kernel.org # v3.6+, at least
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

parent 0fcbf996

fs/namei.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -3273,6 +3273,10 @@ opened:
		goto exit_fput;
		}
		out:
		if (unlikely(error > 0)) {
		WARN_ON(1);
		error = -EINVAL;
		}
		if (got_write)
		mnt_drop_write(nd->path.mnt);
		path_put(&save_parent);

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