Commit 6c1dd1fe authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'integrity-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 

Pull integrity updates from Mimi Zohar:

 - Add a new IMA/EVM maintainer and reviewer

 - Disable EVM on overlayfs

   The EVM HMAC and the original file signatures contain filesystem
   specific metadata (e.g. i_ino, i_generation and s_uuid), preventing
   the security.evm xattr from directly being copied up to the overlay.
   Further before calculating and writing out the overlay file's EVM
   HMAC, EVM must first verify the existing backing file's
   'security.evm' value.

   For now until a solution is developed, disable EVM on overlayfs.

 - One bug fix and two cleanups

* tag 'integrity-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  overlay: disable EVM
  evm: add support to disable EVM on unsupported filesystems
  evm: don't copy up 'security.evm' xattr
  MAINTAINERS: Add Eric Snowberg as a reviewer to IMA
  MAINTAINERS: Add Roberto Sassu as co-maintainer to IMA and EVM
  KEYS: encrypted: Add check for strsep
  ima: Remove EXPERIMENTAL from Kconfig
  ima: Reword IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
parents e9b4c589 c00f94b3

MAINTAINERS

+3 −0
Original line number Diff line number Diff line
@@ -7930,6 +7930,7 @@ F: include/uapi/linux/ext4.h 








Extended Verification Module (EVM)









M:	Mimi Zohar <zohar@linux.ibm.com>









M:	Roberto Sassu <roberto.sassu@huawei.com>









L:	linux-integrity@vger.kernel.org









S:	Supported









T:	git git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git








@@ -10518,7 +10519,9 @@ F:	drivers/crypto/inside-secure/















INTEGRITY MEASUREMENT ARCHITECTURE (IMA)









M:	Mimi Zohar <zohar@linux.ibm.com>









M:	Roberto Sassu <roberto.sassu@huawei.com>









M:	Dmitry Kasatkin <dmitry.kasatkin@gmail.com>









R:	Eric Snowberg <eric.snowberg@oracle.com>









L:	linux-integrity@vger.kernel.org









S:	Supported









T:	git git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
































fs/overlayfs/super.c



+1
−0






























Original line number
Diff line number
Diff line







@@ -1454,6 +1454,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc)







	 * lead to unexpected results.









	 */









	sb->s_iflags |= SB_I_NOUMASK;









	sb->s_iflags |= SB_I_EVM_UNSUPPORTED;



















	err = -ENOMEM;









	root_dentry = ovl_get_root(sb, ctx->upper.dentry, oe);
































include/linux/evm.h



+6
−0






























Original line number
Diff line number
Diff line







@@ -31,6 +31,7 @@ extern void evm_inode_post_setxattr(struct dentry *dentry,







				    const char *xattr_name,









				    const void *xattr_value,









				    size_t xattr_value_len);









extern int evm_inode_copy_up_xattr(const char *name);









extern int evm_inode_removexattr(struct mnt_idmap *idmap,









				 struct dentry *dentry, const char *xattr_name);









extern void evm_inode_post_removexattr(struct dentry *dentry,








@@ -117,6 +118,11 @@ static inline void evm_inode_post_setxattr(struct dentry *dentry,







	return;









}



















static inline int  evm_inode_copy_up_xattr(const char *name)









{









	return 0;









}



















static inline int evm_inode_removexattr(struct mnt_idmap *idmap,









					struct dentry *dentry,









					const char *xattr_name)
































include/linux/fs.h



+1
−0






























Original line number
Diff line number
Diff line







@@ -1166,6 +1166,7 @@ extern int send_sigurg(struct fown_struct *fown);







#define SB_I_USERNS_VISIBLE		0x00000010 /* fstype already mounted */









#define SB_I_IMA_UNVERIFIABLE_SIGNATURE	0x00000020









#define SB_I_UNTRUSTED_MOUNTER		0x00000040









#define SB_I_EVM_UNSUPPORTED		0x00000080



















#define SB_I_SKIP_SYNC	0x00000100	/* Skip superblock at global sync */









#define SB_I_PERSB_BDI	0x00000200	/* has a per-sb bdi */
































security/integrity/evm/evm_main.c



+41
−1






























Original line number
Diff line number
Diff line







@@ -151,6 +151,17 @@ static int evm_find_protected_xattrs(struct dentry *dentry)







	return count;









}



















static int is_unsupported_fs(struct dentry *dentry)









{









	struct inode *inode = d_backing_inode(dentry);



















	if (inode->i_sb->s_iflags & SB_I_EVM_UNSUPPORTED) {









		pr_info_once("%s not supported\n", inode->i_sb->s_type->name);









		return 1;









	}









	return 0;









}



















/*









 * evm_verify_hmac - calculate and compare the HMAC with the EVM xattr









 *








@@ -181,6 +192,9 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,







		     iint->evm_status == INTEGRITY_PASS_IMMUTABLE))









		return iint->evm_status;



















	if (is_unsupported_fs(dentry))









		return INTEGRITY_UNKNOWN;



















	/* if status is not PASS, try to check again - against -ENOMEM */



















	/* first need to know the sig type */








@@ -408,6 +422,9 @@ enum integrity_status evm_verifyxattr(struct dentry *dentry,







	if (!evm_key_loaded() || !evm_protected_xattr(xattr_name))









		return INTEGRITY_UNKNOWN;



















	if (is_unsupported_fs(dentry))









		return INTEGRITY_UNKNOWN;



















	if (!iint) {









		iint = integrity_iint_find(d_backing_inode(dentry));









		if (!iint)








@@ -491,15 +508,21 @@ static int evm_protect_xattr(struct mnt_idmap *idmap,







	if (strcmp(xattr_name, XATTR_NAME_EVM) == 0) {









		if (!capable(CAP_SYS_ADMIN))









			return -EPERM;









		if (is_unsupported_fs(dentry))









			return -EPERM;









	} else if (!evm_protected_xattr(xattr_name)) {









		if (!posix_xattr_acl(xattr_name))









			return 0;









		if (is_unsupported_fs(dentry))









			return 0;



















		evm_status = evm_verify_current_integrity(dentry);









		if ((evm_status == INTEGRITY_PASS) ||









		    (evm_status == INTEGRITY_NOXATTRS))









			return 0;









		goto out;









	}









	} else if (is_unsupported_fs(dentry))









		return 0;



















	evm_status = evm_verify_current_integrity(dentry);









	if (evm_status == INTEGRITY_NOXATTRS) {








@@ -750,6 +773,9 @@ void evm_inode_post_setxattr(struct dentry *dentry, const char *xattr_name,







	if (!(evm_initialized & EVM_INIT_HMAC))









		return;



















	if (is_unsupported_fs(dentry))









		return;



















	evm_update_evmxattr(dentry, xattr_name, xattr_value, xattr_value_len);









}


















@@ -814,8 +840,12 @@ int evm_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,







	if (evm_initialized & EVM_ALLOW_METADATA_WRITES)









		return 0;



















	if (is_unsupported_fs(dentry))









		return 0;



















	if (!(ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)))









		return 0;



















	evm_status = evm_verify_current_integrity(dentry);









	/*









	 * Writing attrs is safe for portable signatures, as portable signatures








@@ -859,10 +889,20 @@ void evm_inode_post_setattr(struct dentry *dentry, int ia_valid)







	if (!(evm_initialized & EVM_INIT_HMAC))









		return;



















	if (is_unsupported_fs(dentry))









		return;



















	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID))









		evm_update_evmxattr(dentry, NULL, NULL, 0);









}



















int evm_inode_copy_up_xattr(const char *name)









{









	if (strcmp(name, XATTR_NAME_EVM) == 0)









		return 1; /* Discard */









	return -EOPNOTSUPP;









}



















/*









 * evm_inode_init_security - initializes security.evm HMAC value









 */