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| author |   Amir Goldstein <amir73il@gmail.com> | 2019-07-12 15:24:34 +0300 |
|---|---|---|
| committer |   Miklos Szeredi <mszeredi@redhat.com> | 2019-07-16 13:23:40 +0200 |
| commit | 0be0bfd2de9dfdd2098a9c5b14bdd8f739c9165d (patch) | |
| tree | 9fdb5305b90a0baffbdd019fed86e023da52e646 /fs/overlayfs/ovl_entry.h | |
| parent | Linux 5.2 (diff) | |
| download | linux-dev-0be0bfd2de9dfdd2098a9c5b14bdd8f739c9165d.tar.xz linux-dev-0be0bfd2de9dfdd2098a9c5b14bdd8f739c9165d.zip | |
ovl: fix regression caused by overlapping layers detection
Once upon a time, commit 2cac0c00a6cd ("ovl: get exclusive ownership on
upper/work dirs") in v4.13 added some sanity checks on overlayfs layers.
This change caused a docker regression. The root cause was mount leaks
by docker, which as far as I know, still exist.
To mitigate the regression, commit 85fdee1eef1a ("ovl: fix regression
caused by exclusive upper/work dir protection") in v4.14 turned the
mount errors into warnings for the default index=off configuration.
Recently, commit 146d62e5a586 ("ovl: detect overlapping layers") in
v5.2, re-introduced exclusive upper/work dir checks regardless of
index=off configuration.
This changes the status quo and mount leak related bug reports have
started to re-surface. Restore the status quo to fix the regressions.
To clarify, index=off does NOT relax overlapping layers check for this
ovelayfs mount. index=off only relaxes exclusive upper/work dir checks
with another overlayfs mount.
To cover the part of overlapping layers detection that used the
exclusive upper/work dir checks to detect overlap with self upper/work
dir, add a trap also on the work base dir.
Link: https://github.com/moby/moby/issues/34672
Link: https://lore.kernel.org/linux-fsdevel/20171006121405.GA32700@veci.piliscsaba.szeredi.hu/
Link: https://github.com/containers/libpod/issues/3540
Fixes: 146d62e5a586 ("ovl: detect overlapping layers")
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Tested-by: Colin Walters <walters@verbum.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/ovl_entry.h')
| -rw-r--r-- | fs/overlayfs/ovl_entry.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 28a2d12a1029..a8279280e88d 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -66,6 +66,7 @@ struct ovl_fs { bool workdir_locked; /* Traps in ovl inode cache */ struct inode *upperdir_trap; + struct inode *workbasedir_trap; struct inode *workdir_trap; struct inode *indexdir_trap; /* Inode numbers in all layers do not use the high xino_bits */ |