* [PATCH 1/2] overlayfs: Conditionally use O_LARGEFILE in ovl_copy_up()
@ 2015-09-18 10:45 David Howells
2015-09-18 10:45 ` [PATCH 2/2] overlayfs: Fix dentry reference leak David Howells
0 siblings, 1 reply; 3+ messages in thread
From: David Howells @ 2015-09-18 10:45 UTC (permalink / raw)
To: miklos; +Cc: dhowells, linux-kernel, linux-unionfs, viro
Open the lower file with O_LARGEFILE in ovl_copy_up() if the lower file is
>= 4GiB in size.
Reported-by: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---
fs/overlayfs/copy_up.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 84d693d37428..89b4cb3773d7 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -76,16 +76,19 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
struct file *new_file;
loff_t old_pos = 0;
loff_t new_pos = 0;
- int error = 0;
+ int error = 0, o_flag = 0;
if (len == 0)
return 0;
- old_file = ovl_path_open(old, O_RDONLY);
+ if (i_size_read(d_inode(old->dentry)) > MAX_NON_LFS)
+ o_flag |= O_LARGEFILE;
+
+ old_file = ovl_path_open(old, o_flag | O_RDONLY);
if (IS_ERR(old_file))
return PTR_ERR(old_file);
- new_file = ovl_path_open(new, O_WRONLY);
+ new_file = ovl_path_open(new, o_flag | O_WRONLY);
if (IS_ERR(new_file)) {
error = PTR_ERR(new_file);
goto out_fput;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/2] overlayfs: Fix dentry reference leak
2015-09-18 10:45 [PATCH 1/2] overlayfs: Conditionally use O_LARGEFILE in ovl_copy_up() David Howells
@ 2015-09-18 10:45 ` David Howells
2015-09-21 8:19 ` Miklos Szeredi
0 siblings, 1 reply; 3+ messages in thread
From: David Howells @ 2015-09-18 10:45 UTC (permalink / raw)
To: miklos; +Cc: dhowells, linux-kernel, linux-unionfs, viro
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>
---
fs/overlayfs/copy_up.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 89b4cb3773d7..d3a5990fd2b9 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -270,7 +270,7 @@ out:
out_cleanup:
ovl_cleanup(wdir, newdentry);
- goto out;
+ goto out2;
}
/*
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 2/2] overlayfs: Fix dentry reference leak
2015-09-18 10:45 ` [PATCH 2/2] overlayfs: Fix dentry reference leak David Howells
@ 2015-09-21 8:19 ` Miklos Szeredi
0 siblings, 0 replies; 3+ messages in thread
From: Miklos Szeredi @ 2015-09-21 8:19 UTC (permalink / raw)
To: David Howells; +Cc: linux-kernel, linux-unionfs, viro
Hi David,
Applied both patches.
Thanks,
Miklos
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-09-21 8:19 UTC | newest]
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2015-09-18 10:45 [PATCH 1/2] overlayfs: Conditionally use O_LARGEFILE in ovl_copy_up() David Howells
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2015-09-21 8:19 ` Miklos Szeredi
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