* [PATCH][v3] overlayfs: Do not lose security.capability xattr over metadata file copy-up
@ 2019-01-30 19:01 Vivek Goyal
2019-01-30 19:14 ` Amir Goldstein
2019-02-04 9:05 ` Miklos Szeredi
0 siblings, 2 replies; 4+ messages in thread
From: Vivek Goyal @ 2019-01-30 19:01 UTC (permalink / raw)
To: linux-unionfs, Amir Goldstein, Miklos Szeredi
If a file has been copied up metadata only, and later data is copied up,
upper loses any security.capability xattr it has (underlying filesystem
clears it as upon file write).
>From a user's point of view, this is just a file copy-up and that should
not result in losing security.capability xattr. Hence, before data copy
up, save security.capability xattr (if any) and restore it on upper after
data copy up is complete.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
fs/overlayfs/copy_up.c | 24 ++++++++++++++++++-
fs/overlayfs/overlayfs.h | 1
fs/overlayfs/util.c | 58 +++++++++++++++++++++++++++++++++--------------
3 files changed, 65 insertions(+), 18 deletions(-)
Index: rhvgoyal-linux/fs/overlayfs/util.c
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/util.c 2019-01-30 13:44:46.123840084 -0500
+++ rhvgoyal-linux/fs/overlayfs/util.c 2019-01-30 13:48:50.433840084 -0500
@@ -863,31 +863,61 @@ bool ovl_is_metacopy_dentry(struct dentr
return (oe->numlower > 1);
}
-char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
+size_t ovl_getxattr(struct dentry *dentry, char *name, void **value,
+ size_t *size, int padding)
{
int res;
- char *s, *next, *buf = NULL;
+ void *buf = NULL;
- res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, NULL, 0);
+ res = vfs_getxattr(dentry, name, NULL, 0);
if (res < 0) {
if (res == -ENODATA || res == -EOPNOTSUPP)
- return NULL;
+ return 0;
goto fail;
}
- buf = kzalloc(res + padding + 1, GFP_KERNEL);
- if (!buf)
- return ERR_PTR(-ENOMEM);
-
if (res == 0)
goto invalid;
- res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, buf, res);
+ buf = kzalloc(res + padding, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ res = vfs_getxattr(dentry, name, buf, res);
if (res < 0)
goto fail;
+
if (res == 0)
goto invalid;
+ *value = buf;
+ if (size)
+ *size = res;
+
+ return res;
+
+err_free:
+ kfree(buf);
+ return res;
+fail:
+ pr_warn_ratelimited("overlayfs: failed to get xattr %s: err=%i)\n", name, res);
+ goto err_free;
+invalid:
+ pr_warn_ratelimited("overlayfs: invalid xattr %s \n", name);
+ res = -EINVAL;
+ goto err_free;
+}
+
+char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
+{
+ int res;
+ char *s, *next, *buf = NULL;
+
+ res = ovl_getxattr(dentry, OVL_XATTR_REDIRECT, (void **)&buf, NULL,
+ padding + 1);
+ if (res <= 0)
+ return ERR_PTR(res);
+
if (buf[0] == '/') {
for (s = buf; *s++ == '/'; s = next) {
next = strchrnul(s, '/');
@@ -900,15 +930,9 @@ char *ovl_get_redirect_xattr(struct dent
}
return buf;
-
-err_free:
- kfree(buf);
- return ERR_PTR(res);
-fail:
- pr_warn_ratelimited("overlayfs: failed to get redirect (%i)\n", res);
- goto err_free;
invalid:
pr_warn_ratelimited("overlayfs: invalid redirect (%s)\n", buf);
res = -EINVAL;
- goto err_free;
+ kfree(buf);
+ return ERR_PTR(res);
}
Index: rhvgoyal-linux/fs/overlayfs/overlayfs.h
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/overlayfs.h 2019-01-30 13:44:46.121840084 -0500
+++ rhvgoyal-linux/fs/overlayfs/overlayfs.h 2019-01-30 13:44:48.623840084 -0500
@@ -277,6 +277,7 @@ int ovl_lock_rename_workdir(struct dentr
int ovl_check_metacopy_xattr(struct dentry *dentry);
bool ovl_is_metacopy_dentry(struct dentry *dentry);
char *ovl_get_redirect_xattr(struct dentry *dentry, int padding);
+size_t ovl_getxattr(struct dentry *dentry, char *name, void **value, size_t *size, int padding);
static inline bool ovl_is_impuredir(struct dentry *dentry)
{
Index: rhvgoyal-linux/fs/overlayfs/copy_up.c
===================================================================
--- rhvgoyal-linux.orig/fs/overlayfs/copy_up.c 2019-01-30 13:44:46.119840084 -0500
+++ rhvgoyal-linux/fs/overlayfs/copy_up.c 2019-01-30 13:44:48.624840084 -0500
@@ -742,6 +742,8 @@ static int ovl_copy_up_meta_inode_data(s
{
struct path upperpath, datapath;
int err;
+ void *capability = NULL;
+ size_t cap_size;
ovl_path_upper(c->dentry, &upperpath);
if (WARN_ON(upperpath.dentry == NULL))
@@ -751,9 +753,29 @@ static int ovl_copy_up_meta_inode_data(s
if (WARN_ON(datapath.dentry == NULL))
return -EIO;
+ if (c->stat.size) {
+ cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS, &capability, &cap_size, 0);
+ if (cap_size < 0)
+ return cap_size;
+ }
+
err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size);
- if (err)
+ if (err) {
+ kfree(capability);
return err;
+ }
+
+ /*
+ * Writing to upper file will clear security.capability xattr. We
+ * don't want that to happen for normal copy-up operation.
+ */
+ if (capability) {
+ err = ovl_do_setxattr(upperpath.dentry, XATTR_NAME_CAPS, capability, cap_size, 0);
+ kfree(capability);
+ if (err)
+ return err;
+ }
+
err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY);
if (err)
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH][v3] overlayfs: Do not lose security.capability xattr over metadata file copy-up
2019-01-30 19:01 [PATCH][v3] overlayfs: Do not lose security.capability xattr over metadata file copy-up Vivek Goyal
@ 2019-01-30 19:14 ` Amir Goldstein
2019-02-04 9:05 ` Miklos Szeredi
1 sibling, 0 replies; 4+ messages in thread
From: Amir Goldstein @ 2019-01-30 19:14 UTC (permalink / raw)
To: Vivek Goyal; +Cc: overlayfs, Miklos Szeredi
On Wed, Jan 30, 2019 at 9:01 PM Vivek Goyal <vgoyal@redhat.com> wrote:
>
> If a file has been copied up metadata only, and later data is copied up,
> upper loses any security.capability xattr it has (underlying filesystem
> clears it as upon file write).
>
> From a user's point of view, this is just a file copy-up and that should
> not result in losing security.capability xattr. Hence, before data copy
> up, save security.capability xattr (if any) and restore it on upper after
> data copy up is complete.
>
> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
> ---
> fs/overlayfs/copy_up.c | 24 ++++++++++++++++++-
> fs/overlayfs/overlayfs.h | 1
> fs/overlayfs/util.c | 58 +++++++++++++++++++++++++++++++++--------------
> 3 files changed, 65 insertions(+), 18 deletions(-)
>
> Index: rhvgoyal-linux/fs/overlayfs/util.c
> ===================================================================
> --- rhvgoyal-linux.orig/fs/overlayfs/util.c 2019-01-30 13:44:46.123840084 -0500
> +++ rhvgoyal-linux/fs/overlayfs/util.c 2019-01-30 13:48:50.433840084 -0500
> @@ -863,31 +863,61 @@ bool ovl_is_metacopy_dentry(struct dentr
> return (oe->numlower > 1);
> }
>
> -char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
> +size_t ovl_getxattr(struct dentry *dentry, char *name, void **value,
> + size_t *size, int padding)
> {
> int res;
> - char *s, *next, *buf = NULL;
> + void *buf = NULL;
>
> - res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, NULL, 0);
> + res = vfs_getxattr(dentry, name, NULL, 0);
> if (res < 0) {
> if (res == -ENODATA || res == -EOPNOTSUPP)
> - return NULL;
> + return 0;
> goto fail;
> }
>
> - buf = kzalloc(res + padding + 1, GFP_KERNEL);
> - if (!buf)
> - return ERR_PTR(-ENOMEM);
> -
> if (res == 0)
> goto invalid;
>
> - res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, buf, res);
> + buf = kzalloc(res + padding, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + res = vfs_getxattr(dentry, name, buf, res);
> if (res < 0)
> goto fail;
> +
> if (res == 0)
> goto invalid;
>
> + *value = buf;
> + if (size)
> + *size = res;
> +
> + return res;
> +
> +err_free:
> + kfree(buf);
> + return res;
> +fail:
> + pr_warn_ratelimited("overlayfs: failed to get xattr %s: err=%i)\n", name, res);
> + goto err_free;
> +invalid:
> + pr_warn_ratelimited("overlayfs: invalid xattr %s \n", name);
> + res = -EINVAL;
> + goto err_free;
> +}
> +
> +char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
> +{
> + int res;
> + char *s, *next, *buf = NULL;
> +
> + res = ovl_getxattr(dentry, OVL_XATTR_REDIRECT, (void **)&buf, NULL,
> + padding + 1);
> + if (res <= 0)
> + return ERR_PTR(res);
> +
> if (buf[0] == '/') {
> for (s = buf; *s++ == '/'; s = next) {
> next = strchrnul(s, '/');
> @@ -900,15 +930,9 @@ char *ovl_get_redirect_xattr(struct dent
> }
>
> return buf;
> -
> -err_free:
> - kfree(buf);
> - return ERR_PTR(res);
> -fail:
> - pr_warn_ratelimited("overlayfs: failed to get redirect (%i)\n", res);
> - goto err_free;
> invalid:
> pr_warn_ratelimited("overlayfs: invalid redirect (%s)\n", buf);
> res = -EINVAL;
> - goto err_free;
> + kfree(buf);
> + return ERR_PTR(res);
> }
> Index: rhvgoyal-linux/fs/overlayfs/overlayfs.h
> ===================================================================
> --- rhvgoyal-linux.orig/fs/overlayfs/overlayfs.h 2019-01-30 13:44:46.121840084 -0500
> +++ rhvgoyal-linux/fs/overlayfs/overlayfs.h 2019-01-30 13:44:48.623840084 -0500
> @@ -277,6 +277,7 @@ int ovl_lock_rename_workdir(struct dentr
> int ovl_check_metacopy_xattr(struct dentry *dentry);
> bool ovl_is_metacopy_dentry(struct dentry *dentry);
> char *ovl_get_redirect_xattr(struct dentry *dentry, int padding);
> +size_t ovl_getxattr(struct dentry *dentry, char *name, void **value, size_t *size, int padding);
>
> static inline bool ovl_is_impuredir(struct dentry *dentry)
> {
> Index: rhvgoyal-linux/fs/overlayfs/copy_up.c
> ===================================================================
> --- rhvgoyal-linux.orig/fs/overlayfs/copy_up.c 2019-01-30 13:44:46.119840084 -0500
> +++ rhvgoyal-linux/fs/overlayfs/copy_up.c 2019-01-30 13:44:48.624840084 -0500
> @@ -742,6 +742,8 @@ static int ovl_copy_up_meta_inode_data(s
> {
> struct path upperpath, datapath;
> int err;
> + void *capability = NULL;
> + size_t cap_size;
>
> ovl_path_upper(c->dentry, &upperpath);
> if (WARN_ON(upperpath.dentry == NULL))
> @@ -751,9 +753,29 @@ static int ovl_copy_up_meta_inode_data(s
> if (WARN_ON(datapath.dentry == NULL))
> return -EIO;
>
> + if (c->stat.size) {
> + cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS, &capability, &cap_size, 0);
> + if (cap_size < 0)
> + return cap_size;
> + }
> +
> err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size);
> - if (err)
> + if (err) {
> + kfree(capability);
> return err;
> + }
> +
> + /*
> + * Writing to upper file will clear security.capability xattr. We
> + * don't want that to happen for normal copy-up operation.
> + */
> + if (capability) {
> + err = ovl_do_setxattr(upperpath.dentry, XATTR_NAME_CAPS, capability, cap_size, 0);
> + kfree(capability);
> + if (err)
> + return err;
> + }
> +
>
> err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY);
> if (err)
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH][v3] overlayfs: Do not lose security.capability xattr over metadata file copy-up
2019-01-30 19:01 [PATCH][v3] overlayfs: Do not lose security.capability xattr over metadata file copy-up Vivek Goyal
2019-01-30 19:14 ` Amir Goldstein
@ 2019-02-04 9:05 ` Miklos Szeredi
2019-02-04 19:36 ` Vivek Goyal
1 sibling, 1 reply; 4+ messages in thread
From: Miklos Szeredi @ 2019-02-04 9:05 UTC (permalink / raw)
To: Vivek Goyal; +Cc: linux-unionfs, Amir Goldstein
On Wed, Jan 30, 2019 at 02:01:57PM -0500, Vivek Goyal wrote:
> If a file has been copied up metadata only, and later data is copied up,
> upper loses any security.capability xattr it has (underlying filesystem
> clears it as upon file write).
>
> From a user's point of view, this is just a file copy-up and that should
> not result in losing security.capability xattr. Hence, before data copy
> up, save security.capability xattr (if any) and restore it on upper after
> data copy up is complete.
>
> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cleaned it up a bit. Hope I didn't break it...
Thanks,
Miklos
---
fs/overlayfs/copy_up.c | 27 +++++++++++++++++++++--
fs/overlayfs/overlayfs.h | 2 +
fs/overlayfs/util.c | 55 +++++++++++++++++++++++++++++------------------
3 files changed, 62 insertions(+), 22 deletions(-)
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -863,28 +863,49 @@ bool ovl_is_metacopy_dentry(struct dentr
return (oe->numlower > 1);
}
-char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
+ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
+ size_t padding)
{
- int res;
- char *s, *next, *buf = NULL;
+ ssize_t res;
+ char *buf = NULL;
- res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, NULL, 0);
+ res = vfs_getxattr(dentry, name, NULL, 0);
if (res < 0) {
if (res == -ENODATA || res == -EOPNOTSUPP)
- return NULL;
+ return -ENODATA;
goto fail;
}
- buf = kzalloc(res + padding + 1, GFP_KERNEL);
- if (!buf)
- return ERR_PTR(-ENOMEM);
+ if (res != 0) {
+ buf = kzalloc(res + padding, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ res = vfs_getxattr(dentry, name, buf, res);
+ if (res < 0)
+ goto fail;
+ }
+ *value = buf;
- if (res == 0)
- goto invalid;
+ return res;
+
+fail:
+ pr_warn_ratelimited("overlayfs: failed to get xattr %s: err=%zi)\n",
+ name, res);
+ kfree(buf);
+ return res;
+}
+
+char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
+{
+ int res;
+ char *s, *next, *buf = NULL;
- res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, buf, res);
+ res = ovl_getxattr(dentry, OVL_XATTR_REDIRECT, &buf, padding + 1);
+ if (res == -ENODATA)
+ return NULL;
if (res < 0)
- goto fail;
+ return ERR_PTR(res);
if (res == 0)
goto invalid;
@@ -900,15 +921,9 @@ char *ovl_get_redirect_xattr(struct dent
}
return buf;
-
-err_free:
- kfree(buf);
- return ERR_PTR(res);
-fail:
- pr_warn_ratelimited("overlayfs: failed to get redirect (%i)\n", res);
- goto err_free;
invalid:
pr_warn_ratelimited("overlayfs: invalid redirect (%s)\n", buf);
res = -EINVAL;
- goto err_free;
+ kfree(buf);
+ return ERR_PTR(res);
}
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -277,6 +277,8 @@ int ovl_lock_rename_workdir(struct dentr
int ovl_check_metacopy_xattr(struct dentry *dentry);
bool ovl_is_metacopy_dentry(struct dentry *dentry);
char *ovl_get_redirect_xattr(struct dentry *dentry, int padding);
+ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
+ size_t padding);
static inline bool ovl_is_impuredir(struct dentry *dentry)
{
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -742,6 +742,8 @@ static int ovl_copy_up_meta_inode_data(s
{
struct path upperpath, datapath;
int err;
+ char *capability = NULL;
+ ssize_t uninitialized_var(cap_size);
ovl_path_upper(c->dentry, &upperpath);
if (WARN_ON(upperpath.dentry == NULL))
@@ -751,15 +753,36 @@ static int ovl_copy_up_meta_inode_data(s
if (WARN_ON(datapath.dentry == NULL))
return -EIO;
+ if (c->stat.size) {
+ err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS,
+ &capability, 0);
+ if (err < 0 && err != -ENODATA)
+ goto out;
+ }
+
err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size);
if (err)
- return err;
+ goto out_free;
+
+ /*
+ * Writing to upper file will clear security.capability xattr. We
+ * don't want that to happen for normal copy-up operation.
+ */
+ if (capability) {
+ err = ovl_do_setxattr(upperpath.dentry, XATTR_NAME_CAPS, capability, cap_size, 0);
+ if (err)
+ goto out_free;
+ }
+
err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY);
if (err)
- return err;
+ goto out_free;
ovl_set_upperdata(d_inode(c->dentry));
+out_free:
+ kfree(capability);
+out:
return err;
}
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH][v3] overlayfs: Do not lose security.capability xattr over metadata file copy-up
2019-02-04 9:05 ` Miklos Szeredi
@ 2019-02-04 19:36 ` Vivek Goyal
0 siblings, 0 replies; 4+ messages in thread
From: Vivek Goyal @ 2019-02-04 19:36 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: linux-unionfs, Amir Goldstein
On Mon, Feb 04, 2019 at 10:05:26AM +0100, Miklos Szeredi wrote:
> On Wed, Jan 30, 2019 at 02:01:57PM -0500, Vivek Goyal wrote:
> > If a file has been copied up metadata only, and later data is copied up,
> > upper loses any security.capability xattr it has (underlying filesystem
> > clears it as upon file write).
> >
> > From a user's point of view, this is just a file copy-up and that should
> > not result in losing security.capability xattr. Hence, before data copy
> > up, save security.capability xattr (if any) and restore it on upper after
> > data copy up is complete.
> >
> > Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
>
>
> Cleaned it up a bit. Hope I didn't break it...
Hi Miklos,
I compiled it and xfstest I wrote to test it passes. Patch also looks good
to me.
Thanks
Vivek
>
> Thanks,
> Miklos
>
> ---
> fs/overlayfs/copy_up.c | 27 +++++++++++++++++++++--
> fs/overlayfs/overlayfs.h | 2 +
> fs/overlayfs/util.c | 55 +++++++++++++++++++++++++++++------------------
> 3 files changed, 62 insertions(+), 22 deletions(-)
>
> --- a/fs/overlayfs/util.c
> +++ b/fs/overlayfs/util.c
> @@ -863,28 +863,49 @@ bool ovl_is_metacopy_dentry(struct dentr
> return (oe->numlower > 1);
> }
>
> -char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
> +ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
> + size_t padding)
> {
> - int res;
> - char *s, *next, *buf = NULL;
> + ssize_t res;
> + char *buf = NULL;
>
> - res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, NULL, 0);
> + res = vfs_getxattr(dentry, name, NULL, 0);
> if (res < 0) {
> if (res == -ENODATA || res == -EOPNOTSUPP)
> - return NULL;
> + return -ENODATA;
> goto fail;
> }
>
> - buf = kzalloc(res + padding + 1, GFP_KERNEL);
> - if (!buf)
> - return ERR_PTR(-ENOMEM);
> + if (res != 0) {
> + buf = kzalloc(res + padding, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + res = vfs_getxattr(dentry, name, buf, res);
> + if (res < 0)
> + goto fail;
> + }
> + *value = buf;
>
> - if (res == 0)
> - goto invalid;
> + return res;
> +
> +fail:
> + pr_warn_ratelimited("overlayfs: failed to get xattr %s: err=%zi)\n",
> + name, res);
> + kfree(buf);
> + return res;
> +}
> +
> +char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
> +{
> + int res;
> + char *s, *next, *buf = NULL;
>
> - res = vfs_getxattr(dentry, OVL_XATTR_REDIRECT, buf, res);
> + res = ovl_getxattr(dentry, OVL_XATTR_REDIRECT, &buf, padding + 1);
> + if (res == -ENODATA)
> + return NULL;
> if (res < 0)
> - goto fail;
> + return ERR_PTR(res);
> if (res == 0)
> goto invalid;
>
> @@ -900,15 +921,9 @@ char *ovl_get_redirect_xattr(struct dent
> }
>
> return buf;
> -
> -err_free:
> - kfree(buf);
> - return ERR_PTR(res);
> -fail:
> - pr_warn_ratelimited("overlayfs: failed to get redirect (%i)\n", res);
> - goto err_free;
> invalid:
> pr_warn_ratelimited("overlayfs: invalid redirect (%s)\n", buf);
> res = -EINVAL;
> - goto err_free;
> + kfree(buf);
> + return ERR_PTR(res);
> }
> --- a/fs/overlayfs/overlayfs.h
> +++ b/fs/overlayfs/overlayfs.h
> @@ -277,6 +277,8 @@ int ovl_lock_rename_workdir(struct dentr
> int ovl_check_metacopy_xattr(struct dentry *dentry);
> bool ovl_is_metacopy_dentry(struct dentry *dentry);
> char *ovl_get_redirect_xattr(struct dentry *dentry, int padding);
> +ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
> + size_t padding);
>
> static inline bool ovl_is_impuredir(struct dentry *dentry)
> {
> --- a/fs/overlayfs/copy_up.c
> +++ b/fs/overlayfs/copy_up.c
> @@ -742,6 +742,8 @@ static int ovl_copy_up_meta_inode_data(s
> {
> struct path upperpath, datapath;
> int err;
> + char *capability = NULL;
> + ssize_t uninitialized_var(cap_size);
>
> ovl_path_upper(c->dentry, &upperpath);
> if (WARN_ON(upperpath.dentry == NULL))
> @@ -751,15 +753,36 @@ static int ovl_copy_up_meta_inode_data(s
> if (WARN_ON(datapath.dentry == NULL))
> return -EIO;
>
> + if (c->stat.size) {
> + err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS,
> + &capability, 0);
> + if (err < 0 && err != -ENODATA)
> + goto out;
> + }
> +
> err = ovl_copy_up_data(&datapath, &upperpath, c->stat.size);
> if (err)
> - return err;
> + goto out_free;
> +
> + /*
> + * Writing to upper file will clear security.capability xattr. We
> + * don't want that to happen for normal copy-up operation.
> + */
> + if (capability) {
> + err = ovl_do_setxattr(upperpath.dentry, XATTR_NAME_CAPS, capability, cap_size, 0);
> + if (err)
> + goto out_free;
> + }
> +
>
> err = vfs_removexattr(upperpath.dentry, OVL_XATTR_METACOPY);
> if (err)
> - return err;
> + goto out_free;
>
> ovl_set_upperdata(d_inode(c->dentry));
> +out_free:
> + kfree(capability);
> +out:
> return err;
> }
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-02-04 19:36 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-01-30 19:01 [PATCH][v3] overlayfs: Do not lose security.capability xattr over metadata file copy-up Vivek Goyal
2019-01-30 19:14 ` Amir Goldstein
2019-02-04 9:05 ` Miklos Szeredi
2019-02-04 19:36 ` Vivek Goyal
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