mirror of
https://github.com/torvalds/linux.git
synced 2024-11-22 04:02:20 +00:00
selinux: Convert isec->lock into a spinlock
Convert isec->lock from a mutex into a spinlock. Instead of holding the lock while sleeping in inode_doinit_with_dentry, set isec->initialized to LABEL_PENDING and release the lock. Then, when the sid has been determined, re-acquire the lock. If isec->initialized is still set to LABEL_PENDING, set isec->sid; otherwise, the sid has been set by another task (LABEL_INITIALIZED) or invalidated (LABEL_INVALID) in the meantime. This fixes a deadlock on gfs2 where * one task is in inode_doinit_with_dentry -> gfs2_getxattr, holds isec->lock, and tries to acquire the inode's glock, and * another task is in do_xmote -> inode_go_inval -> selinux_inode_invalidate_secctx, holds the inode's glock, and tries to acquire isec->lock. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> [PM: minor tweaks to keep checkpatch.pl happy] Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Andreas Gruenbacher
Paul Moore
parent
3322d0d64f
commit
9287aed2ad
@ -231,7 +231,7 @@ static int inode_alloc_security(struct inode *inode)
|
||||
if (!isec)
|
||||
return -ENOMEM;
|
||||
|
||||
mutex_init(&isec->lock);
|
||||
spin_lock_init(&isec->lock);
|
||||
INIT_LIST_HEAD(&isec->list);
|
||||
isec->inode = inode;
|
||||
isec->sid = SECINITSID_UNLABELED;
|
||||
@ -1382,7 +1382,8 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
{
|
||||
struct superblock_security_struct *sbsec = NULL;
|
||||
struct inode_security_struct *isec = inode->i_security;
|
||||
u32 sid;
|
||||
u32 task_sid, sid = 0;
|
||||
u16 sclass;
|
||||
struct dentry *dentry;
|
||||
#define INITCONTEXTLEN 255
|
||||
char *context = NULL;
|
||||
@ -1392,7 +1393,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
if (isec->initialized == LABEL_INITIALIZED)
|
||||
return 0;
|
||||
|
||||
mutex_lock(&isec->lock);
|
||||
spin_lock(&isec->lock);
|
||||
if (isec->initialized == LABEL_INITIALIZED)
|
||||
goto out_unlock;
|
||||
|
||||
@ -1411,12 +1412,18 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
sclass = isec->sclass;
|
||||
task_sid = isec->task_sid;
|
||||
sid = isec->sid;
|
||||
isec->initialized = LABEL_PENDING;
|
||||
spin_unlock(&isec->lock);
|
||||
|
||||
switch (sbsec->behavior) {
|
||||
case SECURITY_FS_USE_NATIVE:
|
||||
break;
|
||||
case SECURITY_FS_USE_XATTR:
|
||||
if (!(inode->i_opflags & IOP_XATTR)) {
|
||||
isec->sid = sbsec->def_sid;
|
||||
sid = sbsec->def_sid;
|
||||
break;
|
||||
}
|
||||
/* Need a dentry, since the xattr API requires one.
|
||||
@ -1438,7 +1445,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
* inode_doinit with a dentry, before these inodes could
|
||||
* be used again by userspace.
|
||||
*/
|
||||
goto out_unlock;
|
||||
goto out;
|
||||
}
|
||||
|
||||
len = INITCONTEXTLEN;
|
||||
@ -1446,7 +1453,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
if (!context) {
|
||||
rc = -ENOMEM;
|
||||
dput(dentry);
|
||||
goto out_unlock;
|
||||
goto out;
|
||||
}
|
||||
context[len] = '\0';
|
||||
rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
|
||||
@ -1457,14 +1464,14 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
|
||||
if (rc < 0) {
|
||||
dput(dentry);
|
||||
goto out_unlock;
|
||||
goto out;
|
||||
}
|
||||
len = rc;
|
||||
context = kmalloc(len+1, GFP_NOFS);
|
||||
if (!context) {
|
||||
rc = -ENOMEM;
|
||||
dput(dentry);
|
||||
goto out_unlock;
|
||||
goto out;
|
||||
}
|
||||
context[len] = '\0';
|
||||
rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
|
||||
@ -1476,7 +1483,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
"%d for dev=%s ino=%ld\n", __func__,
|
||||
-rc, inode->i_sb->s_id, inode->i_ino);
|
||||
kfree(context);
|
||||
goto out_unlock;
|
||||
goto out;
|
||||
}
|
||||
/* Map ENODATA to the default file SID */
|
||||
sid = sbsec->def_sid;
|
||||
@ -1506,28 +1513,25 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
}
|
||||
}
|
||||
kfree(context);
|
||||
isec->sid = sid;
|
||||
break;
|
||||
case SECURITY_FS_USE_TASK:
|
||||
isec->sid = isec->task_sid;
|
||||
sid = task_sid;
|
||||
break;
|
||||
case SECURITY_FS_USE_TRANS:
|
||||
/* Default to the fs SID. */
|
||||
isec->sid = sbsec->sid;
|
||||
sid = sbsec->sid;
|
||||
|
||||
/* Try to obtain a transition SID. */
|
||||
rc = security_transition_sid(isec->task_sid, sbsec->sid,
|
||||
isec->sclass, NULL, &sid);
|
||||
rc = security_transition_sid(task_sid, sid, sclass, NULL, &sid);
|
||||
if (rc)
|
||||
goto out_unlock;
|
||||
isec->sid = sid;
|
||||
goto out;
|
||||
break;
|
||||
case SECURITY_FS_USE_MNTPOINT:
|
||||
isec->sid = sbsec->mntpoint_sid;
|
||||
sid = sbsec->mntpoint_sid;
|
||||
break;
|
||||
default:
|
||||
/* Default to the fs superblock SID. */
|
||||
isec->sid = sbsec->sid;
|
||||
sid = sbsec->sid;
|
||||
|
||||
if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) {
|
||||
/* We must have a dentry to determine the label on
|
||||
@ -1550,21 +1554,30 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
|
||||
* could be used again by userspace.
|
||||
*/
|
||||
if (!dentry)
|
||||
goto out_unlock;
|
||||
rc = selinux_genfs_get_sid(dentry, isec->sclass,
|
||||
goto out;
|
||||
rc = selinux_genfs_get_sid(dentry, sclass,
|
||||
sbsec->flags, &sid);
|
||||
dput(dentry);
|
||||
if (rc)
|
||||
goto out_unlock;
|
||||
isec->sid = sid;
|
||||
goto out;
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
isec->initialized = LABEL_INITIALIZED;
|
||||
out:
|
||||
spin_lock(&isec->lock);
|
||||
if (isec->initialized == LABEL_PENDING) {
|
||||
if (!sid || rc) {
|
||||
isec->initialized = LABEL_INVALID;
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
isec->initialized = LABEL_INITIALIZED;
|
||||
isec->sid = sid;
|
||||
}
|
||||
|
||||
out_unlock:
|
||||
mutex_unlock(&isec->lock);
|
||||
spin_unlock(&isec->lock);
|
||||
return rc;
|
||||
}
|
||||
|
||||
@ -3195,9 +3208,11 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
|
||||
}
|
||||
|
||||
isec = backing_inode_security(dentry);
|
||||
spin_lock(&isec->lock);
|
||||
isec->sclass = inode_mode_to_security_class(inode->i_mode);
|
||||
isec->sid = newsid;
|
||||
isec->initialized = LABEL_INITIALIZED;
|
||||
spin_unlock(&isec->lock);
|
||||
|
||||
return;
|
||||
}
|
||||
@ -3290,9 +3305,11 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
|
||||
if (rc)
|
||||
return rc;
|
||||
|
||||
spin_lock(&isec->lock);
|
||||
isec->sclass = inode_mode_to_security_class(inode->i_mode);
|
||||
isec->sid = newsid;
|
||||
isec->initialized = LABEL_INITIALIZED;
|
||||
spin_unlock(&isec->lock);
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -3953,9 +3970,11 @@ static void selinux_task_to_inode(struct task_struct *p,
|
||||
struct inode_security_struct *isec = inode->i_security;
|
||||
u32 sid = task_sid(p);
|
||||
|
||||
spin_lock(&isec->lock);
|
||||
isec->sclass = inode_mode_to_security_class(inode->i_mode);
|
||||
isec->sid = sid;
|
||||
isec->initialized = LABEL_INITIALIZED;
|
||||
spin_unlock(&isec->lock);
|
||||
}
|
||||
|
||||
/* Returns error only if unable to parse addresses */
|
||||
@ -4274,24 +4293,24 @@ static int selinux_socket_post_create(struct socket *sock, int family,
|
||||
const struct task_security_struct *tsec = current_security();
|
||||
struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
|
||||
struct sk_security_struct *sksec;
|
||||
u16 sclass = socket_type_to_security_class(family, type, protocol);
|
||||
u32 sid = SECINITSID_KERNEL;
|
||||
int err = 0;
|
||||
|
||||
isec->sclass = socket_type_to_security_class(family, type, protocol);
|
||||
|
||||
if (kern)
|
||||
isec->sid = SECINITSID_KERNEL;
|
||||
else {
|
||||
err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
|
||||
if (!kern) {
|
||||
err = socket_sockcreate_sid(tsec, sclass, &sid);
|
||||
if (err)
|
||||
return err;
|
||||
}
|
||||
|
||||
isec->sclass = sclass;
|
||||
isec->sid = sid;
|
||||
isec->initialized = LABEL_INITIALIZED;
|
||||
|
||||
if (sock->sk) {
|
||||
sksec = sock->sk->sk_security;
|
||||
sksec->sid = isec->sid;
|
||||
sksec->sclass = isec->sclass;
|
||||
sksec->sclass = sclass;
|
||||
sksec->sid = sid;
|
||||
err = selinux_netlbl_socket_post_create(sock->sk, family);
|
||||
}
|
||||
|
||||
@ -4467,16 +4486,22 @@ static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
|
||||
int err;
|
||||
struct inode_security_struct *isec;
|
||||
struct inode_security_struct *newisec;
|
||||
u16 sclass;
|
||||
u32 sid;
|
||||
|
||||
err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
newisec = inode_security_novalidate(SOCK_INODE(newsock));
|
||||
|
||||
isec = inode_security_novalidate(SOCK_INODE(sock));
|
||||
newisec->sclass = isec->sclass;
|
||||
newisec->sid = isec->sid;
|
||||
spin_lock(&isec->lock);
|
||||
sclass = isec->sclass;
|
||||
sid = isec->sid;
|
||||
spin_unlock(&isec->lock);
|
||||
|
||||
newisec = inode_security_novalidate(SOCK_INODE(newsock));
|
||||
newisec->sclass = sclass;
|
||||
newisec->sid = sid;
|
||||
newisec->initialized = LABEL_INITIALIZED;
|
||||
|
||||
return 0;
|
||||
@ -5979,9 +6004,9 @@ static void selinux_inode_invalidate_secctx(struct inode *inode)
|
||||
{
|
||||
struct inode_security_struct *isec = inode->i_security;
|
||||
|
||||
mutex_lock(&isec->lock);
|
||||
spin_lock(&isec->lock);
|
||||
isec->initialized = LABEL_INVALID;
|
||||
mutex_unlock(&isec->lock);
|
||||
spin_unlock(&isec->lock);
|
||||
}
|
||||
|
||||
/*
|
||||
|
||||
@ -39,7 +39,8 @@ struct task_security_struct {
|
||||
|
||||
enum label_initialized {
|
||||
LABEL_INVALID, /* invalid or not initialized */
|
||||
LABEL_INITIALIZED /* initialized */
|
||||
LABEL_INITIALIZED, /* initialized */
|
||||
LABEL_PENDING
|
||||
};
|
||||
|
||||
struct inode_security_struct {
|
||||
@ -52,7 +53,7 @@ struct inode_security_struct {
|
||||
u32 sid; /* SID of this object */
|
||||
u16 sclass; /* security class of this object */
|
||||
unsigned char initialized; /* initialization flag */
|
||||
struct mutex lock;
|
||||
spinlock_t lock;
|
||||
};
|
||||
|
||||
struct file_security_struct {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user