From 1e41568d7378d1ba8c64ba137b9ddd00b59f893a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 26 Jan 2010 05:43:08 -0500 Subject: Take ima_path_check() in nfsd past dentry_open() in nfsd_open() Signed-off-by: Al Viro --- fs/nfsd/vfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/nfsd') diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index c194793b642b..325959e264ce 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -752,6 +752,8 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, flags, current_cred()); if (IS_ERR(*filp)) host_err = PTR_ERR(*filp); + host_err = ima_path_check(&(*filp)->f_path, + access & (MAY_READ | MAY_WRITE | MAY_EXEC)); out_nfserr: err = nfserrno(host_err); out: @@ -2127,7 +2129,6 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, */ path.mnt = exp->ex_path.mnt; path.dentry = dentry; - err = ima_path_check(&path, acc & (MAY_READ | MAY_WRITE | MAY_EXEC)); nfsd_out: return err? nfserrno(err) : 0; } -- cgit v1.2.3 From 8eb988c70e7709b7bd1a69f0ec53d19ac20dea84 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Wed, 20 Jan 2010 15:35:41 -0500 Subject: fix ima breakage The "Untangling ima mess, part 2 with counters" patch messed up the counters. Based on conversations with Al Viro, this patch streamlines ima_path_check() by removing the counter maintaince. The counters are now updated independently, from measuring the file, in __dentry_open() and alloc_file() by calling ima_counts_get(). ima_path_check() is called from nfsd and do_filp_open(). It also did not measure all files that should have been measured. Reason: ima_path_check() got bogus value passed as mask. [AV: mea culpa] [AV: add missing nfsd bits] Signed-off-by: Mimi Zohar Signed-off-by: Al Viro --- fs/namei.c | 6 +- fs/nfsd/vfs.c | 3 +- include/linux/ima.h | 4 +- security/integrity/ima/ima_main.c | 236 +++++++++++++++----------------------- 4 files changed, 97 insertions(+), 152 deletions(-) (limited to 'fs/nfsd') diff --git a/fs/namei.c b/fs/namei.c index 94a5e60779f9..cd77b6375efd 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1736,8 +1736,7 @@ do_last: if (nd.root.mnt) path_put(&nd.root); if (!IS_ERR(filp)) { - error = ima_path_check(&filp->f_path, filp->f_mode & - (MAY_READ | MAY_WRITE | MAY_EXEC)); + error = ima_path_check(filp, acc_mode); if (error) { fput(filp); filp = ERR_PTR(error); @@ -1797,8 +1796,7 @@ ok: } filp = nameidata_to_filp(&nd); if (!IS_ERR(filp)) { - error = ima_path_check(&filp->f_path, filp->f_mode & - (MAY_READ | MAY_WRITE | MAY_EXEC)); + error = ima_path_check(filp, acc_mode); if (error) { fput(filp); filp = ERR_PTR(error); diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 325959e264ce..32477e3a645c 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -752,8 +752,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, flags, current_cred()); if (IS_ERR(*filp)) host_err = PTR_ERR(*filp); - host_err = ima_path_check(&(*filp)->f_path, - access & (MAY_READ | MAY_WRITE | MAY_EXEC)); + host_err = ima_path_check(*filp, access); out_nfserr: err = nfserrno(host_err); out: diff --git a/include/linux/ima.h b/include/linux/ima.h index 99dc6d5cf7e5..aa55a8f1f5b9 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -17,7 +17,7 @@ struct linux_binprm; extern int ima_bprm_check(struct linux_binprm *bprm); extern int ima_inode_alloc(struct inode *inode); extern void ima_inode_free(struct inode *inode); -extern int ima_path_check(struct path *path, int mask); +extern int ima_path_check(struct file *file, int mask); extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); extern void ima_counts_get(struct file *file); @@ -38,7 +38,7 @@ static inline void ima_inode_free(struct inode *inode) return; } -static inline int ima_path_check(struct path *path, int mask) +static inline int ima_path_check(struct file *file, int mask) { return 0; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index a89f44d5e030..75aee18f6163 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -84,6 +84,36 @@ out: return found; } +/* ima_read_write_check - reflect possible reading/writing errors in the PCR. + * + * When opening a file for read, if the file is already open for write, + * the file could change, resulting in a file measurement error. + * + * Opening a file for write, if the file is already open for read, results + * in a time of measure, time of use (ToMToU) error. + * + * In either case invalidate the PCR. + */ +enum iint_pcr_error { TOMTOU, OPEN_WRITERS }; +static void ima_read_write_check(enum iint_pcr_error error, + struct ima_iint_cache *iint, + struct inode *inode, + const unsigned char *filename) +{ + switch (error) { + case TOMTOU: + if (iint->readcount > 0) + ima_add_violation(inode, filename, "invalid_pcr", + "ToMToU"); + break; + case OPEN_WRITERS: + if (iint->writecount > 0) + ima_add_violation(inode, filename, "invalid_pcr", + "open_writers"); + break; + } +} + /* * Update the counts given an fmode_t */ @@ -98,6 +128,47 @@ static void ima_inc_counts(struct ima_iint_cache *iint, fmode_t mode) iint->writecount++; } +/* + * ima_counts_get - increment file counts + * + * Maintain read/write counters for all files, but only + * invalidate the PCR for measured files: + * - Opening a file for write when already open for read, + * results in a time of measure, time of use (ToMToU) error. + * - Opening a file for read when already open for write, + * could result in a file measurement error. + * + */ +void ima_counts_get(struct file *file) +{ + struct dentry *dentry = file->f_path.dentry; + struct inode *inode = dentry->d_inode; + fmode_t mode = file->f_mode; + struct ima_iint_cache *iint; + int rc; + + if (!ima_initialized || !S_ISREG(inode->i_mode)) + return; + iint = ima_iint_find_get(inode); + if (!iint) + return; + mutex_lock(&iint->mutex); + rc = ima_must_measure(iint, inode, MAY_READ, PATH_CHECK); + if (rc < 0) + goto out; + + if (mode & FMODE_WRITE) { + ima_read_write_check(TOMTOU, iint, inode, dentry->d_name.name); + goto out; + } + ima_read_write_check(OPEN_WRITERS, iint, inode, dentry->d_name.name); +out: + ima_inc_counts(iint, file->f_mode); + mutex_unlock(&iint->mutex); + + kref_put(&iint->refcount, iint_free); +} + /* * Decrement ima counts */ @@ -153,123 +224,6 @@ void ima_file_free(struct file *file) kref_put(&iint->refcount, iint_free); } -/* ima_read_write_check - reflect possible reading/writing errors in the PCR. - * - * When opening a file for read, if the file is already open for write, - * the file could change, resulting in a file measurement error. - * - * Opening a file for write, if the file is already open for read, results - * in a time of measure, time of use (ToMToU) error. - * - * In either case invalidate the PCR. - */ -enum iint_pcr_error { TOMTOU, OPEN_WRITERS }; -static void ima_read_write_check(enum iint_pcr_error error, - struct ima_iint_cache *iint, - struct inode *inode, - const unsigned char *filename) -{ - switch (error) { - case TOMTOU: - if (iint->readcount > 0) - ima_add_violation(inode, filename, "invalid_pcr", - "ToMToU"); - break; - case OPEN_WRITERS: - if (iint->writecount > 0) - ima_add_violation(inode, filename, "invalid_pcr", - "open_writers"); - break; - } -} - -static int get_path_measurement(struct ima_iint_cache *iint, struct file *file, - const unsigned char *filename) -{ - int rc = 0; - - ima_inc_counts(iint, file->f_mode); - - rc = ima_collect_measurement(iint, file); - if (!rc) - ima_store_measurement(iint, file, filename); - return rc; -} - -/** - * ima_path_check - based on policy, collect/store measurement. - * @path: contains a pointer to the path to be measured - * @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE - * - * Measure the file being open for readonly, based on the - * ima_must_measure() policy decision. - * - * Keep read/write counters for all files, but only - * invalidate the PCR for measured files: - * - Opening a file for write when already open for read, - * results in a time of measure, time of use (ToMToU) error. - * - Opening a file for read when already open for write, - * could result in a file measurement error. - * - * Always return 0 and audit dentry_open failures. - * (Return code will be based upon measurement appraisal.) - */ -int ima_path_check(struct path *path, int mask) -{ - struct inode *inode = path->dentry->d_inode; - struct ima_iint_cache *iint; - struct file *file = NULL; - int rc; - - if (!ima_initialized || !S_ISREG(inode->i_mode)) - return 0; - iint = ima_iint_find_get(inode); - if (!iint) - return 0; - - mutex_lock(&iint->mutex); - - rc = ima_must_measure(iint, inode, MAY_READ, PATH_CHECK); - if (rc < 0) - goto out; - - if ((mask & MAY_WRITE) || (mask == 0)) - ima_read_write_check(TOMTOU, iint, inode, - path->dentry->d_name.name); - - if ((mask & (MAY_WRITE | MAY_READ | MAY_EXEC)) != MAY_READ) - goto out; - - ima_read_write_check(OPEN_WRITERS, iint, inode, - path->dentry->d_name.name); - if (!(iint->flags & IMA_MEASURED)) { - struct dentry *dentry = dget(path->dentry); - struct vfsmount *mnt = mntget(path->mnt); - - file = dentry_open(dentry, mnt, O_RDONLY | O_LARGEFILE, - current_cred()); - if (IS_ERR(file)) { - int audit_info = 0; - - integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, - dentry->d_name.name, - "add_measurement", - "dentry_open failed", - 1, audit_info); - file = NULL; - goto out; - } - rc = get_path_measurement(iint, file, dentry->d_name.name); - } -out: - mutex_unlock(&iint->mutex); - if (file) - fput(file); - kref_put(&iint->refcount, iint_free); - return 0; -} -EXPORT_SYMBOL_GPL(ima_path_check); - static int process_measurement(struct file *file, const unsigned char *filename, int mask, int function) { @@ -297,33 +251,6 @@ out: return rc; } -/* - * ima_counts_get - increment file counts - * - * - for IPC shm and shmat file. - * - for nfsd exported files. - * - * Increment the counts for these files to prevent unnecessary - * imbalance messages. - */ -void ima_counts_get(struct file *file) -{ - struct inode *inode = file->f_dentry->d_inode; - struct ima_iint_cache *iint; - - if (!ima_initialized || !S_ISREG(inode->i_mode)) - return; - iint = ima_iint_find_get(inode); - if (!iint) - return; - mutex_lock(&iint->mutex); - ima_inc_counts(iint, file->f_mode); - mutex_unlock(&iint->mutex); - - kref_put(&iint->refcount, iint_free); -} -EXPORT_SYMBOL_GPL(ima_counts_get); - /** * ima_file_mmap - based on policy, collect/store measurement. * @file: pointer to the file to be measured (May be NULL) @@ -369,6 +296,27 @@ int ima_bprm_check(struct linux_binprm *bprm) return 0; } +/** + * ima_path_check - based on policy, collect/store measurement. + * @file: pointer to the file to be measured + * @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE + * + * Measure files based on the ima_must_measure() policy decision. + * + * Always return 0 and audit dentry_open failures. + * (Return code will be based upon measurement appraisal.) + */ +int ima_path_check(struct file *file, int mask) +{ + int rc; + + rc = process_measurement(file, file->f_dentry->d_name.name, + mask & (MAY_READ | MAY_WRITE | MAY_EXEC), + PATH_CHECK); + return 0; +} +EXPORT_SYMBOL_GPL(ima_path_check); + static int __init init_ima(void) { int error; -- cgit v1.2.3 From 9bbb6cad0173e6220f3ac609e26beb48dab3b7cd Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 26 Jan 2010 17:02:40 -0500 Subject: ima: rename ima_path_check to ima_file_check ima_path_check actually deals with files! call it ima_file_check instead. Signed-off-by: Eric Paris Acked-by: Mimi Zohar Signed-off-by: Al Viro --- fs/namei.c | 4 ++-- fs/nfsd/vfs.c | 2 +- include/linux/ima.h | 4 ++-- security/integrity/ima/ima_main.c | 6 +++--- 4 files changed, 8 insertions(+), 8 deletions(-) (limited to 'fs/nfsd') diff --git a/fs/namei.c b/fs/namei.c index cd77b6375efd..d62fdc875f22 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1736,7 +1736,7 @@ do_last: if (nd.root.mnt) path_put(&nd.root); if (!IS_ERR(filp)) { - error = ima_path_check(filp, acc_mode); + error = ima_file_check(filp, acc_mode); if (error) { fput(filp); filp = ERR_PTR(error); @@ -1796,7 +1796,7 @@ ok: } filp = nameidata_to_filp(&nd); if (!IS_ERR(filp)) { - error = ima_path_check(filp, acc_mode); + error = ima_file_check(filp, acc_mode); if (error) { fput(filp); filp = ERR_PTR(error); diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 32477e3a645c..97d79eff6b7f 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -752,7 +752,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, flags, current_cred()); if (IS_ERR(*filp)) host_err = PTR_ERR(*filp); - host_err = ima_path_check(*filp, access); + host_err = ima_file_check(*filp, access); out_nfserr: err = nfserrno(host_err); out: diff --git a/include/linux/ima.h b/include/linux/ima.h index aa55a8f1f5b9..975837e7d6c0 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -17,7 +17,7 @@ struct linux_binprm; extern int ima_bprm_check(struct linux_binprm *bprm); extern int ima_inode_alloc(struct inode *inode); extern void ima_inode_free(struct inode *inode); -extern int ima_path_check(struct file *file, int mask); +extern int ima_file_check(struct file *file, int mask); extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); extern void ima_counts_get(struct file *file); @@ -38,7 +38,7 @@ static inline void ima_inode_free(struct inode *inode) return; } -static inline int ima_path_check(struct file *file, int mask) +static inline int ima_file_check(struct file *file, int mask) { return 0; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index eb1cf6498cc9..b76e1f03ea2b 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -14,7 +14,7 @@ * * File: ima_main.c * implements the IMA hooks: ima_bprm_check, ima_file_mmap, - * and ima_path_check. + * and ima_file_check. */ #include #include @@ -306,7 +306,7 @@ int ima_bprm_check(struct linux_binprm *bprm) * Always return 0 and audit dentry_open failures. * (Return code will be based upon measurement appraisal.) */ -int ima_path_check(struct file *file, int mask) +int ima_file_check(struct file *file, int mask) { int rc; @@ -315,7 +315,7 @@ int ima_path_check(struct file *file, int mask) PATH_CHECK); return 0; } -EXPORT_SYMBOL_GPL(ima_path_check); +EXPORT_SYMBOL_GPL(ima_file_check); static int __init init_ima(void) { -- cgit v1.2.3 From 260c64d23532caf19abb77e696971da05c388489 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Mon, 8 Feb 2010 13:42:26 -0500 Subject: Revert "nfsd4: fix error return when pseudoroot missing" Commit f39bde24b275ddc45d fixed the error return from PUTROOTFH in the case where there is no pseudofilesystem. This is really a case we shouldn't hit on a correctly configured server: in the absence of a root filehandle, there's no point accepting version 4 NFS rpc calls at all. But the shared responsibility between kernel and userspace here means the kernel on its own can't eliminate the possiblity of this happening. And we have indeed gotten this wrong in distro's, so new client-side mount code that attempts to negotiate v4 by default first has to work around this case. Therefore when commit f39bde24b275ddc45d arrived at roughly the same time as the new v4-default mount code, which explicitly checked only for the previous error, the result was previously fine mounts suddenly failing. We'll fix both sides for now: revert the error change, and make the client-side mount workaround more robust. Signed-off-by: J. Bruce Fields --- fs/nfsd/export.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) (limited to 'fs/nfsd') diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index c487810a2366..a0c4016413f1 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -1316,19 +1316,11 @@ rqst_exp_parent(struct svc_rqst *rqstp, struct path *path) static struct svc_export *find_fsidzero_export(struct svc_rqst *rqstp) { - struct svc_export *exp; u32 fsidv[2]; mk_fsid(FSID_NUM, fsidv, 0, 0, 0, NULL); - exp = rqst_exp_find(rqstp, FSID_NUM, fsidv); - /* - * We shouldn't have accepting an nfsv4 request at all if we - * don't have a pseudoexport!: - */ - if (IS_ERR(exp) && PTR_ERR(exp) == -ENOENT) - exp = ERR_PTR(-ESERVERFAULT); - return exp; + return rqst_exp_find(rqstp, FSID_NUM, fsidv); } /* -- cgit v1.2.3 From aeaa5ccd6421fbf9e7ded0ac67b12ea2b9fcf51e Mon Sep 17 00:00:00 2001 From: Chuck Ebbert Date: Mon, 15 Feb 2010 18:07:39 -0500 Subject: vfs: don't call ima_file_check() unconditionally in nfsd_open() commit 1e41568d7378d1ba8c64ba137b9ddd00b59f893a ("Take ima_path_check() in nfsd past dentry_open() in nfsd_open()") moved this code back to its original location but missed the "else". Signed-off-by: Chuck Ebbert Signed-off-by: Al Viro --- fs/nfsd/vfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/nfsd') diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 97d79eff6b7f..8715d194561a 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -752,7 +752,8 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, flags, current_cred()); if (IS_ERR(*filp)) host_err = PTR_ERR(*filp); - host_err = ima_file_check(*filp, access); + else + host_err = ima_file_check(*filp, access); out_nfserr: err = nfserrno(host_err); out: -- cgit v1.2.3