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From: J. R. Okajima <hooanon05@yahoo.co.jp>
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Date: Sun, 7 Feb 2010 06:48:55 +0000 (+1100)
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Subject: ima: fix null pointer deref
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X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Fjmorris%2Fsecurity-testing-2.6.git;a=commitdiff_plain;h=8bb6795424b09db0eca1cccf7a17b93fc28ac7f7
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ima: fix null pointer deref
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The commit 6c21a7f "LSM: imbed ima calls in the security hooks"
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which moves the ima_file_free() call within security_file_free()
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brought a problem into pipe.c.
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In the error path of pipe(2), the allocated resources are freed by
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path_put() and put_filp() (in this order). Since security_file_free()
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refers f_dentry and ima_file_free() refers f_dentry->d_inode, path_put()
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should be called after put_filp().
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Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
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Signed-off-by: James Morris <jmorris@namei.org>
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---
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diff --git a/fs/pipe.c b/fs/pipe.c
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index 37ba29f..90b543d 100644
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--- a/fs/pipe.c
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+++ b/fs/pipe.c
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@@ -1004,9 +1004,10 @@ struct file *create_write_pipe(int flags)
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 void free_write_pipe(struct file *f)
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 {
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+	struct path path = f->f_path;
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 	free_pipe_info(f->f_dentry->d_inode);
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-	path_put(&f->f_path);
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 	put_filp(f);
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+	path_put(&path);
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 }
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 struct file *create_read_pipe(struct file *wrf, int flags)
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@@ -1028,6 +1029,7 @@ int do_pipe_flags(int *fd, int flags)
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 	struct file *fw, *fr;
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 	int error;
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 	int fdw, fdr;
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+	struct path path;
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 	if (flags & ~(O_CLOEXEC | O_NONBLOCK))
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 		return -EINVAL;
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@@ -1061,8 +1063,9 @@ int do_pipe_flags(int *fd, int flags)
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  err_fdr:
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 	put_unused_fd(fdr);
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  err_read_pipe:
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-	path_put(&fr->f_path);
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+	path = fr->f_path;
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 	put_filp(fr);
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+	path_put(&path);
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  err_write_pipe:
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 	free_write_pipe(fw);
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 	return error;