From 18032ca062e621e15683cb61c066ef3dc5414a7b Mon Sep 17 00:00:00 2001 From: David Quigley Date: Thu, 2 May 2013 13:19:10 -0400 Subject: [PATCH] NFSD: Server implementation of MAC Labeling Implement labeled NFS on the server: encoding and decoding, and writing and reading, of file labels. Enabled with CONFIG_NFSD_V4_SECURITY_LABEL. Signed-off-by: Matthew N. Dodd Signed-off-by: Miguel Rodel Felipe Signed-off-by: Phua Eu Gene Signed-off-by: Khin Mi Mi Aung Signed-off-by: J. Bruce Fields --- fs/nfsd/Kconfig | 16 +++++++ fs/nfsd/nfs4proc.c | 41 +++++++++++++++++ fs/nfsd/nfs4xdr.c | 108 +++++++++++++++++++++++++++++++++++++++++---- fs/nfsd/nfsd.h | 18 +++++++- fs/nfsd/vfs.c | 28 ++++++++++++ fs/nfsd/vfs.h | 2 + fs/nfsd/xdr4.h | 4 ++ 7 files changed, 207 insertions(+), 10 deletions(-) diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig index 430b6872806f..dc8f1ef665ce 100644 --- a/fs/nfsd/Kconfig +++ b/fs/nfsd/Kconfig @@ -81,6 +81,22 @@ config NFSD_V4 If unsure, say N. +config NFSD_V4_SECURITY_LABEL + bool "Provide Security Label support for NFSv4 server" + depends on NFSD_V4 && SECURITY + help + + Say Y here if you want enable fine-grained security label attribute + support for NFS version 4. Security labels allow security modules like + SELinux and Smack to label files to facilitate enforcement of their policies. + Without this an NFSv4 mount will have the same label on each file. + + If you do not wish to enable fine-grained security labels SELinux or + Smack policies on NFSv4 files, say N. + + WARNING: there is still a chance of backwards-incompatible protocol changes. + For now we recommend "Y" only for developers and testers." + config NFSD_FAULT_INJECTION bool "NFS server manual fault injection" depends on NFSD_V4 && DEBUG_KERNEL diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 27d74a294515..1a1ff247bc59 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -42,6 +42,36 @@ #include "current_stateid.h" #include "netns.h" +#ifdef CONFIG_NFSD_V4_SECURITY_LABEL +#include + +static inline void +nfsd4_security_inode_setsecctx(struct svc_fh *resfh, struct xdr_netobj *label, u32 *bmval) +{ + struct inode *inode = resfh->fh_dentry->d_inode; + int status; + + mutex_lock(&inode->i_mutex); + status = security_inode_setsecctx(resfh->fh_dentry, + label->data, label->len); + mutex_unlock(&inode->i_mutex); + + if (status) + /* + * XXX: We should really fail the whole open, but we may + * already have created a new file, so it may be too + * late. For now this seems the least of evils: + */ + bmval[2] &= ~FATTR4_WORD2_SECURITY_LABEL; + + return; +} +#else +static inline void +nfsd4_security_inode_setsecctx(struct svc_fh *resfh, struct xdr_netobj *label, u32 *bmval) +{ } +#endif + #define NFSDDBG_FACILITY NFSDDBG_PROC static u32 nfsd_attrmask[] = { @@ -239,6 +269,9 @@ do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, stru (u32 *)open->op_verf.data, &open->op_truncate, &open->op_created); + if (!status && open->op_label.len) + nfsd4_security_inode_setsecctx(resfh, &open->op_label, open->op_bmval); + /* * Following rfc 3530 14.2.16, use the returned bitmask * to indicate which attributes we used to store the @@ -637,6 +670,9 @@ nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, if (status) goto out; + if (create->cr_label.len) + nfsd4_security_inode_setsecctx(&resfh, &create->cr_label, create->cr_bmval); + if (create->cr_acl != NULL) do_set_nfs4_acl(rqstp, &resfh, create->cr_acl, create->cr_bmval); @@ -916,6 +952,11 @@ nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, setattr->sa_acl); if (status) goto out; + if (setattr->sa_label.len) + status = nfsd4_set_nfs4_label(rqstp, &cstate->current_fh, + &setattr->sa_label); + if (status) + goto out; status = nfsd_setattr(rqstp, &cstate->current_fh, &setattr->sa_iattr, 0, (time_t)0); out: diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 9aeacddafa3f..dfca5121de53 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -55,6 +55,11 @@ #include "cache.h" #include "netns.h" +#ifdef CONFIG_NFSD_V4_SECURITY_LABEL +#include +#endif + + #define NFSDDBG_FACILITY NFSDDBG_XDR /* @@ -242,7 +247,8 @@ nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval) static __be32 nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, - struct iattr *iattr, struct nfs4_acl **acl) + struct iattr *iattr, struct nfs4_acl **acl, + struct xdr_netobj *label) { int expected_len, len = 0; u32 dummy32; @@ -380,6 +386,32 @@ nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, goto xdr_error; } } + + label->len = 0; +#ifdef CONFIG_NFSD_V4_SECURITY_LABEL + if (bmval[2] & FATTR4_WORD2_SECURITY_LABEL) { + READ_BUF(4); + len += 4; + READ32(dummy32); /* lfs: we don't use it */ + READ_BUF(4); + len += 4; + READ32(dummy32); /* pi: we don't use it either */ + READ_BUF(4); + len += 4; + READ32(dummy32); + READ_BUF(dummy32); + if (dummy32 > NFSD4_MAX_SEC_LABEL_LEN) + return nfserr_badlabel; + len += (XDR_QUADLEN(dummy32) << 2); + READMEM(buf, dummy32); + label->data = kzalloc(dummy32 + 1, GFP_KERNEL); + if (!label->data) + return nfserr_jukebox; + defer_free(argp, kfree, label->data); + memcpy(label->data, buf, dummy32); + } +#endif + if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0 || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1 || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) @@ -576,7 +608,7 @@ nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create return status; status = nfsd4_decode_fattr(argp, create->cr_bmval, &create->cr_iattr, - &create->cr_acl); + &create->cr_acl, &create->cr_label); if (status) goto out; @@ -827,7 +859,7 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open) case NFS4_CREATE_UNCHECKED: case NFS4_CREATE_GUARDED: status = nfsd4_decode_fattr(argp, open->op_bmval, - &open->op_iattr, &open->op_acl); + &open->op_iattr, &open->op_acl, &open->op_label); if (status) goto out; break; @@ -841,7 +873,7 @@ nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open) READ_BUF(NFS4_VERIFIER_SIZE); COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE); status = nfsd4_decode_fattr(argp, open->op_bmval, - &open->op_iattr, &open->op_acl); + &open->op_iattr, &open->op_acl, &open->op_label); if (status) goto out; break; @@ -1063,7 +1095,7 @@ nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *seta if (status) return status; return nfsd4_decode_fattr(argp, setattr->sa_bmval, &setattr->sa_iattr, - &setattr->sa_acl); + &setattr->sa_acl, &setattr->sa_label); } static __be32 @@ -1954,6 +1986,36 @@ nfsd4_encode_aclname(struct svc_rqst *rqstp, struct nfs4_ace *ace, FATTR4_WORD0_RDATTR_ERROR) #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID +#ifdef CONFIG_NFSD_V4_SECURITY_LABEL +static inline __be32 +nfsd4_encode_security_label(struct svc_rqst *rqstp, void *context, int len, __be32 **pp, int *buflen) +{ + __be32 *p = *pp; + + if (*buflen < ((XDR_QUADLEN(len) << 2) + 4 + 4 + 4)) + return nfserr_resource; + + /* + * For now we use a 0 here to indicate the null translation; in + * the future we may place a call to translation code here. + */ + if ((*buflen -= 8) < 0) + return nfserr_resource; + + WRITE32(0); /* lfs */ + WRITE32(0); /* pi */ + p = xdr_encode_opaque(p, context, len); + *buflen -= (XDR_QUADLEN(len) << 2) + 4; + + *pp = p; + return 0; +} +#else +static inline __be32 +nfsd4_encode_security_label(struct svc_rqst *rqstp, struct dentry *dentry, __be32 **pp, int *buflen) +{ return 0; } +#endif + static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *rdattr_err) { /* As per referral draft: */ @@ -2013,6 +2075,9 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp, int err; int aclsupport = 0; struct nfs4_acl *acl = NULL; + void *context = NULL; + int contextlen; + bool contextsupport = false; struct nfsd4_compoundres *resp = rqstp->rq_resp; u32 minorversion = resp->cstate.minorversion; struct path path = { @@ -2066,6 +2131,21 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp, } } +#ifdef CONFIG_NFSD_V4_SECURITY_LABEL + if ((bmval[2] & FATTR4_WORD2_SECURITY_LABEL) || + bmval[0] & FATTR4_WORD0_SUPPORTED_ATTRS) { + err = security_inode_getsecctx(dentry->d_inode, + &context, &contextlen); + contextsupport = (err == 0); + if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) { + if (err == -EOPNOTSUPP) + bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL; + else if (err) + goto out_nfserr; + } + } +#endif /* CONFIG_NFSD_V4_SECURITY_LABEL */ + if (bmval2) { if ((buflen -= 16) < 0) goto out_resource; @@ -2094,6 +2174,8 @@ nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp, if (!aclsupport) word0 &= ~FATTR4_WORD0_ACL; + if (!contextsupport) + word2 &= ~FATTR4_WORD2_SECURITY_LABEL; if (!word2) { if ((buflen -= 12) < 0) goto out_resource; @@ -2401,6 +2483,12 @@ out_acl: get_parent_attributes(exp, &stat); WRITE64(stat.ino); } + if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) { + status = nfsd4_encode_security_label(rqstp, context, + contextlen, &p, &buflen); + if (status) + goto out; + } if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) { WRITE32(3); WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD0); @@ -2413,6 +2501,8 @@ out_acl: status = nfs_ok; out: + if (context) + security_release_secctx(context, contextlen); kfree(acl); if (fhp == &tempfh) fh_put(&tempfh); @@ -3177,16 +3267,18 @@ nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4 { __be32 *p; - RESERVE_SPACE(12); + RESERVE_SPACE(16); if (nfserr) { - WRITE32(2); + WRITE32(3); + WRITE32(0); WRITE32(0); WRITE32(0); } else { - WRITE32(2); + WRITE32(3); WRITE32(setattr->sa_bmval[0]); WRITE32(setattr->sa_bmval[1]); + WRITE32(setattr->sa_bmval[2]); } ADJUST_ARGS(); return nfserr; diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 15e7e1d531f0..2bbd94e51efc 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -328,6 +328,13 @@ void nfsd_lockd_shutdown(void); #define NFSD4_1_SUPPORTED_ATTRS_WORD2 \ (NFSD4_SUPPORTED_ATTRS_WORD2 | FATTR4_WORD2_SUPPATTR_EXCLCREAT) +#ifdef CONFIG_NFSD_V4_SECURITY_LABEL +#define NFSD4_2_SUPPORTED_ATTRS_WORD2 \ + (NFSD4_1_SUPPORTED_ATTRS_WORD2 | FATTR4_WORD2_SECURITY_LABEL) +#else +#define NFSD4_2_SUPPORTED_ATTRS_WORD2 0 +#endif + static inline u32 nfsd_suppattrs0(u32 minorversion) { return minorversion ? NFSD4_1_SUPPORTED_ATTRS_WORD0 @@ -342,8 +349,11 @@ static inline u32 nfsd_suppattrs1(u32 minorversion) static inline u32 nfsd_suppattrs2(u32 minorversion) { - return minorversion ? NFSD4_1_SUPPORTED_ATTRS_WORD2 - : NFSD4_SUPPORTED_ATTRS_WORD2; + switch (minorversion) { + default: return NFSD4_2_SUPPORTED_ATTRS_WORD2; + case 1: return NFSD4_1_SUPPORTED_ATTRS_WORD2; + case 0: return NFSD4_SUPPORTED_ATTRS_WORD2; + } } /* These will return ERR_INVAL if specified in GETATTR or READDIR. */ @@ -356,7 +366,11 @@ static inline u32 nfsd_suppattrs2(u32 minorversion) #define NFSD_WRITEABLE_ATTRS_WORD1 \ (FATTR4_WORD1_MODE | FATTR4_WORD1_OWNER | FATTR4_WORD1_OWNER_GROUP \ | FATTR4_WORD1_TIME_ACCESS_SET | FATTR4_WORD1_TIME_MODIFY_SET) +#ifdef CONFIG_NFSD_V4_SECURITY_LABEL +#define NFSD_WRITEABLE_ATTRS_WORD2 FATTR4_WORD2_SECURITY_LABEL +#else #define NFSD_WRITEABLE_ATTRS_WORD2 0 +#endif #define NFSD_SUPPATTR_EXCLCREAT_WORD0 \ NFSD_WRITEABLE_ATTRS_WORD0 diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 84ce601d8063..1e757fa45c40 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -28,6 +28,7 @@ #include #include #include +#include #ifdef CONFIG_NFSD_V3 #include "xdr3.h" @@ -621,6 +622,33 @@ int nfsd4_is_junction(struct dentry *dentry) return 0; return 1; } +#ifdef CONFIG_NFSD_V4_SECURITY_LABEL +__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp, + struct xdr_netobj *label) +{ + __be32 error; + int host_error; + struct dentry *dentry; + + error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); + if (error) + return error; + + dentry = fhp->fh_dentry; + + mutex_lock(&dentry->d_inode->i_mutex); + host_error = security_inode_setsecctx(dentry, label->data, label->len); + mutex_unlock(&dentry->d_inode->i_mutex); + return nfserrno(host_error); +} +#else +__be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp, + struct xdr_netobj *label) +{ + return nfserr_notsupp; +} +#endif + #endif /* defined(CONFIG_NFSD_V4) */ #ifdef CONFIG_NFSD_V3 diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index 8d2b40d71669..a4be2e389670 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -55,6 +55,8 @@ int nfsd_mountpoint(struct dentry *, struct svc_export *); __be32 nfsd4_set_nfs4_acl(struct svc_rqst *, struct svc_fh *, struct nfs4_acl *); int nfsd4_get_nfs4_acl(struct svc_rqst *, struct dentry *, struct nfs4_acl **); +__be32 nfsd4_set_nfs4_label(struct svc_rqst *, struct svc_fh *, + struct xdr_netobj *); #endif /* CONFIG_NFSD_V4 */ __be32 nfsd_create(struct svc_rqst *, struct svc_fh *, char *name, int len, struct iattr *attrs, diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h index 3b271d2092b6..b3ed6446ed8e 100644 --- a/fs/nfsd/xdr4.h +++ b/fs/nfsd/xdr4.h @@ -40,6 +40,7 @@ #include "state.h" #include "nfsd.h" +#define NFSD4_MAX_SEC_LABEL_LEN 2048 #define NFSD4_MAX_TAGLEN 128 #define XDR_LEN(n) (((n) + 3) & ~3) @@ -118,6 +119,7 @@ struct nfsd4_create { struct iattr cr_iattr; /* request */ struct nfsd4_change_info cr_cinfo; /* response */ struct nfs4_acl *cr_acl; + struct xdr_netobj cr_label; }; #define cr_linklen u.link.namelen #define cr_linkname u.link.name @@ -246,6 +248,7 @@ struct nfsd4_open { struct nfs4_file *op_file; /* used during processing */ struct nfs4_ol_stateid *op_stp; /* used during processing */ struct nfs4_acl *op_acl; + struct xdr_netobj op_label; }; #define op_iattr iattr @@ -330,6 +333,7 @@ struct nfsd4_setattr { u32 sa_bmval[3]; /* request */ struct iattr sa_iattr; /* request */ struct nfs4_acl *sa_acl; + struct xdr_netobj sa_label; }; struct nfsd4_setclientid { -- 2.39.5