sysfs: Update sysfs_setxattr so it updates secdata under the sysfs_mutex
The sysfs_mutex is required to ensure updates are and will remain atomic with respect to other inode iattr updates, that do not happen through the filesystem. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
parent
d3a3b0adad
commit
f44d3e7857
|
@ -123,23 +123,39 @@ int sysfs_setattr(struct dentry * dentry, struct iattr * iattr)
|
||||||
return error;
|
return error;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
static int sysfs_sd_setsecdata(struct sysfs_dirent *sd, void **secdata, u32 *secdata_len)
|
||||||
|
{
|
||||||
|
struct sysfs_inode_attrs *iattrs;
|
||||||
|
void *old_secdata;
|
||||||
|
size_t old_secdata_len;
|
||||||
|
|
||||||
|
iattrs = sd->s_iattr;
|
||||||
|
if (!iattrs)
|
||||||
|
iattrs = sysfs_init_inode_attrs(sd);
|
||||||
|
if (!iattrs)
|
||||||
|
return -ENOMEM;
|
||||||
|
|
||||||
|
old_secdata = iattrs->ia_secdata;
|
||||||
|
old_secdata_len = iattrs->ia_secdata_len;
|
||||||
|
|
||||||
|
iattrs->ia_secdata = *secdata;
|
||||||
|
iattrs->ia_secdata_len = *secdata_len;
|
||||||
|
|
||||||
|
*secdata = old_secdata;
|
||||||
|
*secdata_len = old_secdata_len;
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
|
int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
|
||||||
size_t size, int flags)
|
size_t size, int flags)
|
||||||
{
|
{
|
||||||
struct sysfs_dirent *sd = dentry->d_fsdata;
|
struct sysfs_dirent *sd = dentry->d_fsdata;
|
||||||
struct sysfs_inode_attrs *iattrs;
|
|
||||||
void *secdata;
|
void *secdata;
|
||||||
int error;
|
int error;
|
||||||
u32 secdata_len = 0;
|
u32 secdata_len = 0;
|
||||||
|
|
||||||
if (!sd)
|
if (!sd)
|
||||||
return -EINVAL;
|
return -EINVAL;
|
||||||
if (!sd->s_iattr)
|
|
||||||
sd->s_iattr = sysfs_init_inode_attrs(sd);
|
|
||||||
if (!sd->s_iattr)
|
|
||||||
return -ENOMEM;
|
|
||||||
|
|
||||||
iattrs = sd->s_iattr;
|
|
||||||
|
|
||||||
if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN)) {
|
if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN)) {
|
||||||
const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
|
const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
|
||||||
|
@ -151,12 +167,13 @@ int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
|
||||||
&secdata, &secdata_len);
|
&secdata, &secdata_len);
|
||||||
if (error)
|
if (error)
|
||||||
goto out;
|
goto out;
|
||||||
if (iattrs->ia_secdata)
|
|
||||||
security_release_secctx(iattrs->ia_secdata,
|
|
||||||
iattrs->ia_secdata_len);
|
|
||||||
iattrs->ia_secdata = secdata;
|
|
||||||
iattrs->ia_secdata_len = secdata_len;
|
|
||||||
|
|
||||||
|
mutex_lock(&sysfs_mutex);
|
||||||
|
error = sysfs_sd_setsecdata(sd, &secdata, &secdata_len);
|
||||||
|
mutex_unlock(&sysfs_mutex);
|
||||||
|
|
||||||
|
if (secdata)
|
||||||
|
security_release_secctx(secdata, secdata_len);
|
||||||
} else
|
} else
|
||||||
return -EINVAL;
|
return -EINVAL;
|
||||||
out:
|
out:
|
||||||
|
|
Loading…
Reference in New Issue