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author | David Howells <dhowells@redhat.com> | 2015-09-18 10:45:22 (GMT) |
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committer | Miklos Szeredi <miklos@szeredi.hu> | 2015-10-12 13:56:20 (GMT) |
commit | ab79efab0a0ba01a74df782eb7fa44b044dae8b5 (patch) | |
tree | fc70625885e132efa3c66e14b4a035e5aaa0a136 /kernel | |
parent | 0480334fa60488d12ae101a02d7d9e1a3d03d7dd (diff) | |
download | linux-ab79efab0a0ba01a74df782eb7fa44b044dae8b5.tar.xz |
ovl: fix dentry reference leak
In ovl_copy_up_locked(), newdentry is leaked if the function exits through
out_cleanup as this just to out after calling ovl_cleanup() - which doesn't
actually release the ref on newdentry.
The out_cleanup segment should instead exit through out2 as certainly
newdentry leaks - and possibly upper does also, though this isn't caught
given the catch of newdentry.
Without this fix, something like the following is seen:
BUG: Dentry ffff880023e9eb20{i=f861,n=#ffff880023e82d90} still in use (1) [unmount of tmpfs tmpfs]
BUG: Dentry ffff880023ece640{i=0,n=bigfile} still in use (1) [unmount of tmpfs tmpfs]
when unmounting the upper layer after an error occurred in copyup.
An error can be induced by creating a big file in a lower layer with
something like:
dd if=/dev/zero of=/lower/a/bigfile bs=65536 count=1 seek=$((0xf000))
to create a large file (4.1G). Overlay an upper layer that is too small
(on tmpfs might do) and then induce a copy up by opening it writably.
Reported-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org> # v3.18+
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions