diff options
Diffstat (limited to 'security/selinux/hooks.c')
| -rw-r--r-- | security/selinux/hooks.c | 60 |
1 files changed, 45 insertions, 15 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 5d92167dbe05..333606b3a8ef 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -490,16 +490,10 @@ static int may_context_mount_inode_relabel(u32 sid, return rc; } -static int selinux_is_sblabel_mnt(struct super_block *sb) +static int selinux_is_genfs_special_handling(struct super_block *sb) { - struct superblock_security_struct *sbsec = sb->s_security; - - return sbsec->behavior == SECURITY_FS_USE_XATTR || - sbsec->behavior == SECURITY_FS_USE_TRANS || - sbsec->behavior == SECURITY_FS_USE_TASK || - sbsec->behavior == SECURITY_FS_USE_NATIVE || - /* Special handling. Genfs but also in-core setxattr handler */ - !strcmp(sb->s_type->name, "sysfs") || + /* Special handling. Genfs but also in-core setxattr handler */ + return !strcmp(sb->s_type->name, "sysfs") || !strcmp(sb->s_type->name, "pstore") || !strcmp(sb->s_type->name, "debugfs") || !strcmp(sb->s_type->name, "tracefs") || @@ -509,6 +503,34 @@ static int selinux_is_sblabel_mnt(struct super_block *sb) !strcmp(sb->s_type->name, "cgroup2"))); } +static int selinux_is_sblabel_mnt(struct super_block *sb) +{ + struct superblock_security_struct *sbsec = sb->s_security; + + /* + * IMPORTANT: Double-check logic in this function when adding a new + * SECURITY_FS_USE_* definition! + */ + BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7); + + switch (sbsec->behavior) { + case SECURITY_FS_USE_XATTR: + case SECURITY_FS_USE_TRANS: + case SECURITY_FS_USE_TASK: + case SECURITY_FS_USE_NATIVE: + return 1; + + case SECURITY_FS_USE_GENFS: + return selinux_is_genfs_special_handling(sb); + + /* Never allow relabeling on context mounts */ + case SECURITY_FS_USE_MNTPOINT: + case SECURITY_FS_USE_NONE: + default: + return 0; + } +} + static int sb_finish_set_opts(struct super_block *sb) { struct superblock_security_struct *sbsec = sb->s_security; @@ -2881,9 +2903,8 @@ static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, if (IS_ERR(isec)) return PTR_ERR(isec); - return avc_has_perm_flags(&selinux_state, - sid, isec->sid, isec->sclass, FILE__READ, &ad, - rcu ? MAY_NOT_BLOCK : 0); + return avc_has_perm(&selinux_state, + sid, isec->sid, isec->sclass, FILE__READ, &ad); } static noinline int audit_inode_permission(struct inode *inode, @@ -2938,7 +2959,9 @@ static int selinux_inode_permission(struct inode *inode, int mask) return PTR_ERR(isec); rc = avc_has_perm_noaudit(&selinux_state, - sid, isec->sid, isec->sclass, perms, 0, &avd); + sid, isec->sid, isec->sclass, perms, + (flags & MAY_NOT_BLOCK) ? AVC_NONBLOCKING : 0, + &avd); audited = avc_audit_required(perms, &avd, rc, from_access ? FILE__AUDIT_ACCESS : 0, &denied); @@ -3197,12 +3220,16 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) { struct inode_security_struct *isec = inode_security_novalidate(inode); + struct superblock_security_struct *sbsec = inode->i_sb->s_security; u32 newsid; int rc; if (strcmp(name, XATTR_SELINUX_SUFFIX)) return -EOPNOTSUPP; + if (!(sbsec->flags & SBLABEL_MNT)) + return -EOPNOTSUPP; + if (!value || !size) return -EACCES; @@ -4445,7 +4472,7 @@ err_af: } /* This supports connect(2) and SCTP connect services such as sctp_connectx(3) - * and sctp_sendmsg(3) as described in Documentation/security/LSM-sctp.rst + * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst */ static int selinux_socket_connect_helper(struct socket *sock, struct sockaddr *address, int addrlen) @@ -6236,7 +6263,10 @@ static void selinux_inode_invalidate_secctx(struct inode *inode) */ static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) { - return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0); + int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, + ctx, ctxlen, 0); + /* Do not return error when suppressing label (SBLABEL_MNT not set). */ + return rc == -EOPNOTSUPP ? 0 : rc; } /* |