| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 309/342] do_last(): dont let a bogus return value from ->open() et.al. to confuse us | Date | Tue, 01 Mar 2016 23:55:27 +0000 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Al Viro <viro@zeniv.linux.org.uk>
commit c80567c82ae4814a41287618e315a60ecf513be6 upstream.
... 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.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/namei.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/fs/namei.c +++ b/fs/namei.c @@ -3210,6 +3210,10 @@ 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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