Messages in this thread Patch in this message | | | Date | Sun, 8 Apr 2012 23:40:00 -0700 | Subject | Re: [PATCH] Add security.selinux XATTR support for the UBIFS. Also fix couple of bugs in UBIFS extended attribute length calculation. | From | Subodh Nijsure <> |
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On Sun, Apr 8, 2012 at 7:37 PM, Casey Schaufler <casey@schaufler-ca.com> wrote: > On 4/8/2012 6:47 AM, Subodh Nijsure wrote: >> TESTING: Tested on MX28 based platforms using Micron MT29F2G08ABAEAH4 NAND >> With these change we are able to label UBIFS filesystem with security.selinux >> and run system with selinux enabled. >> Also ran integck test on UBI filesystem. >> >> Signed-off-by: Subodh Nijsure <snijsure@grid-net.com> > > There is no reason to restrict xattr support to SELinux. > SELinux specific behavior belongs within the SELinux LSM. > This code needs to support the full xattr semantics. > > Nacked-by: Casey Schaufler <casey@scahufler-ca.com> > >> --- >> fs/ubifs/dir.c | 4 ++ >> fs/ubifs/file.c | 6 ++ >> fs/ubifs/journal.c | 12 +++- >> fs/ubifs/super.c | 3 + >> fs/ubifs/ubifs.h | 9 +++ >> fs/ubifs/xattr.c | 147 ++++++++++++++++++++++++++++++++++++++++++++++++---- >> 6 files changed, 167 insertions(+), 14 deletions(-) >> >> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c >> index ec9f187..f4e06c4 100644 >> --- a/fs/ubifs/dir.c >> +++ b/fs/ubifs/dir.c >> @@ -293,6 +293,7 @@ static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode, >> ubifs_release_budget(c, &req); >> insert_inode_hash(inode); >> d_instantiate(dentry, inode); >> + ubifs_init_security(dir, inode, &dentry->d_name); >> return 0; >> >> out_cancel: >> @@ -754,6 +755,7 @@ static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) >> >> ubifs_release_budget(c, &req); >> d_instantiate(dentry, inode); >> + ubifs_init_security(dir, inode, &dentry->d_name); >> return 0; >> >> out_cancel: >> @@ -831,6 +833,7 @@ static int ubifs_mknod(struct inode *dir, struct dentry *dentry, >> ubifs_release_budget(c, &req); >> insert_inode_hash(inode); >> d_instantiate(dentry, inode); >> + ubifs_init_security(dir, inode, &dentry->d_name); >> return 0; >> >> out_cancel: >> @@ -907,6 +910,7 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, >> ubifs_release_budget(c, &req); >> insert_inode_hash(inode); >> d_instantiate(dentry, inode); >> + ubifs_init_security(dir, inode, &dentry->d_name); >> return 0; >> >> out_cancel: >> diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c >> index 5c8f6dc..b8e9d66 100644 >> --- a/fs/ubifs/file.c >> +++ b/fs/ubifs/file.c >> @@ -1575,6 +1575,12 @@ const struct inode_operations ubifs_symlink_inode_operations = { >> .follow_link = ubifs_follow_link, >> .setattr = ubifs_setattr, >> .getattr = ubifs_getattr, >> +#ifdef CONFIG_UBIFS_FS_XATTR >> + .setxattr = ubifs_symlink_setxattr, >> + .getxattr = ubifs_symlink_getxattr, >> + .listxattr = ubifs_listxattr, >> + .removexattr = ubifs_removexattr, >> +#endif >> }; >> >> const struct file_operations ubifs_file_operations = { >> diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c >> index 2f438ab..725dc17 100644 >> --- a/fs/ubifs/journal.c >> +++ b/fs/ubifs/journal.c >> @@ -553,7 +553,8 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, >> >> dbg_jnl("ino %lu, dent '%.*s', data len %d in dir ino %lu", >> inode->i_ino, nm->len, nm->name, ui->data_len, dir->i_ino); >> - ubifs_assert(dir_ui->data_len == 0); >> + if (!xent) >> + ubifs_assert(dir_ui->data_len == 0); >> ubifs_assert(mutex_is_locked(&dir_ui->ui_mutex)); >> >> dlen = UBIFS_DENT_NODE_SZ + nm->len + 1; >> @@ -572,7 +573,11 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, >> >> aligned_dlen = ALIGN(dlen, 8); >> aligned_ilen = ALIGN(ilen, 8); >> - len = aligned_dlen + aligned_ilen + UBIFS_INO_NODE_SZ; >> + /* Make sure to account for dir_ui+data_len in length calculation >> + * in case there is extended attribute. >> + */ >> + len = aligned_dlen + aligned_ilen + >> + UBIFS_INO_NODE_SZ + dir_ui->data_len; >> dent = kmalloc(len, GFP_NOFS); >> if (!dent) >> return -ENOMEM; >> @@ -649,7 +654,8 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, >> >> ino_key_init(c, &ino_key, dir->i_ino); >> ino_offs += aligned_ilen; >> - err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, UBIFS_INO_NODE_SZ); >> + err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, >> + UBIFS_INO_NODE_SZ + dir_ui->data_len); >> if (err) >> goto out_ro; >> >> diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c >> index 76e4e05..c28ac04 100644 >> --- a/fs/ubifs/super.c >> +++ b/fs/ubifs/super.c >> @@ -2061,6 +2061,9 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) >> if (c->max_inode_sz > MAX_LFS_FILESIZE) >> sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE; >> sb->s_op = &ubifs_super_operations; >> +#ifdef CONFIG_UBIFS_FS_XATTR >> + sb->s_xattr = ubifs_xattr_handlers; >> +#endif >> >> mutex_lock(&c->umount_mutex); >> err = mount_ubifs(c); >> diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h >> index 93d59ac..60b57f7 100644 >> --- a/fs/ubifs/ubifs.h >> +++ b/fs/ubifs/ubifs.h >> @@ -36,6 +36,7 @@ >> #include <linux/mtd/ubi.h> >> #include <linux/pagemap.h> >> #include <linux/backing-dev.h> >> +#include <linux/security.h> >> #include "ubifs-media.h" >> >> /* Version of this UBIFS implementation */ >> @@ -1454,6 +1455,7 @@ extern spinlock_t ubifs_infos_lock; >> extern atomic_long_t ubifs_clean_zn_cnt; >> extern struct kmem_cache *ubifs_inode_slab; >> extern const struct super_operations ubifs_super_operations; >> +extern const struct xattr_handler *ubifs_xattr_handlers[]; >> extern const struct address_space_operations ubifs_file_address_operations; >> extern const struct file_operations ubifs_file_operations; >> extern const struct inode_operations ubifs_file_inode_operations; >> @@ -1736,10 +1738,17 @@ int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry, >> struct kstat *stat); >> >> /* xattr.c */ >> + >> int ubifs_setxattr(struct dentry *dentry, const char *name, >> const void *value, size_t size, int flags); >> +int ubifs_init_security(struct inode *dentry, struct inode *inode, >> + const struct qstr *qstr); >> +int ubifs_symlink_setxattr(struct dentry *dentry, const char *name, >> + const void *value, size_t size, int flags); >> ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf, >> size_t size); >> +ssize_t ubifs_symlink_getxattr(struct dentry *dentry, const char *name, >> + void *buf, size_t size); >> ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size); >> int ubifs_removexattr(struct dentry *dentry, const char *name); >> >> diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c >> index 85b2722..a402c7d 100644 >> --- a/fs/ubifs/xattr.c >> +++ b/fs/ubifs/xattr.c >> @@ -209,11 +209,11 @@ static int change_xattr(struct ubifs_info *c, struct inode *host, >> goto out_free; >> } >> inode->i_size = ui->ui_size = size; >> - ui->data_len = size; >> >> mutex_lock(&host_ui->ui_mutex); >> host->i_ctime = ubifs_current_time(host); >> host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len); >> + ui->data_len = size; >> host_ui->xattr_size += CALC_XATTR_BYTES(size); >> >> /* >> @@ -293,18 +293,16 @@ static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum) >> return ERR_PTR(-EINVAL); >> } >> >> -int ubifs_setxattr(struct dentry *dentry, const char *name, >> - const void *value, size_t size, int flags) >> +static int __ubifs_setxattr(struct inode *host, const char *name, >> + const void *value, size_t size, int flags) >> { >> - struct inode *inode, *host = dentry->d_inode; >> + struct inode *inode; >> struct ubifs_info *c = host->i_sb->s_fs_info; >> struct qstr nm = { .name = name, .len = strlen(name) }; >> struct ubifs_dent_node *xent; >> union ubifs_key key; >> int err, type; >> >> - dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name, >> - host->i_ino, dentry->d_name.len, dentry->d_name.name, size); >> ubifs_assert(mutex_is_locked(&host->i_mutex)); >> >> if (size > UBIFS_MAX_INO_DATA) >> @@ -356,10 +354,29 @@ out_free: >> return err; >> } >> >> -ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf, >> - size_t size) >> +int ubifs_symlink_setxattr(struct dentry *dentry, const char *name, >> + const void *value, size_t size, int flags) >> { >> - struct inode *inode, *host = dentry->d_inode; >> + struct inode *host = dentry->d_inode; >> + dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name, >> + host->i_ino, dentry->d_name.len, dentry->d_name.name, size); >> + return __ubifs_setxattr(host, name, value, size, flags); >> +} >> + >> +int ubifs_setxattr(struct dentry *dentry, const char *name, >> + const void *value, size_t size, int flags) >> +{ >> + struct inode *host = dentry->d_inode; >> + dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name, >> + host->i_ino, dentry->d_name.len, dentry->d_name.name, size); >> + return __ubifs_setxattr(host, name, value, size, flags); >> +} >> + >> +static >> +ssize_t __ubifs_getxattr(struct inode *host, const char *name, void *buf, >> + size_t size) >> +{ >> + struct inode *inode; >> struct ubifs_info *c = host->i_sb->s_fs_info; >> struct qstr nm = { .name = name, .len = strlen(name) }; >> struct ubifs_inode *ui; >> @@ -367,8 +384,8 @@ ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf, >> union ubifs_key key; >> int err; >> >> - dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name, >> - host->i_ino, dentry->d_name.len, dentry->d_name.name, size); >> + dbg_gen("xattr '%s', ino %lu buf size %zd", name, >> + host->i_ino, size); >> >> err = check_namespace(&nm); >> if (err < 0) >> @@ -416,6 +433,25 @@ out_unlock: >> return err; >> } >> >> +ssize_t ubifs_symlink_getxattr(struct dentry *dentry, const char *name, >> + void *buf, size_t size) >> +{ >> + struct inode *host = dentry->d_inode; >> + dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name, >> + host->i_ino, dentry->d_name.len, dentry->d_name.name, size); >> + return __ubifs_getxattr(host, name, buf, size); >> +} >> + >> +ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf, >> + size_t size) >> +{ >> + struct inode *host = dentry->d_inode; >> + dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name, >> + host->i_ino, dentry->d_name.len, dentry->d_name.name, size); >> + return __ubifs_getxattr(host, name, buf, size); >> +} >> + >> + >> ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size) >> { >> union ubifs_key key; >> @@ -568,3 +604,92 @@ out_free: >> kfree(xent); >> return err; >> } >> + >> +size_t >> +ubifs_security_listxattr(struct dentry *d, char *list, size_t list_size, >> + const char *name, size_t name_len, int flags) >> +{ >> + const int prefix_len = XATTR_SECURITY_PREFIX_LEN; >> + const size_t total_len = prefix_len + name_len + 1; >> + if (list && total_len <= list_size) { >> + memcpy(list, XATTR_SECURITY_PREFIX, prefix_len); >> + memcpy(list+prefix_len, name, name_len); >> + list[prefix_len + name_len] = '\0'; >> + } >> + return total_len; >> +} >> + >> + >> +int ubifs_security_getxattr(struct dentry *d, const char *name, >> + void *buffer, size_t size, int flags) >> +{ >> + if (strcmp(name, "") == 0) >> + return -EINVAL; >> + return __ubifs_getxattr(d->d_inode, XATTR_NAME_SELINUX, buffer, size); >> +} >> + >> + >> +int ubifs_security_setxattr(struct dentry *d, const char *name, >> + const void *value, size_t size, >> + int flags, int handler_flags) >> +{ >> + if (strcmp(name, "") == 0) >> + return -EINVAL; >> + return __ubifs_setxattr(d->d_inode, XATTR_NAME_SELINUX, value, > > This is silly. If you're supporting xattrs there is no reason > single out a particular LSM. Make this general so that Smack > and any other LSM that wants to use xattrs will work. > > Move the changes into the SELinux LSM if you are going to > hard code it. >
Yup, my bad, following change fixes that specific issue and one can set xattr for all security.* namespace. Will submit patch v2 shortly...
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c index a402c7d..c8be7cd 100644 --- a/fs/ubifs/xattr.c +++ b/fs/ubifs/xattr.c @@ -625,7 +625,7 @@ int ubifs_security_getxattr(struct dentry *d, const char *name, { if (strcmp(name, "") == 0) return -EINVAL; - return __ubifs_getxattr(d->d_inode, XATTR_NAME_SELINUX, buffer, size); + return __ubifs_getxattr(d->d_inode, name, buffer, size); }
@@ -635,7 +635,7 @@ int ubifs_security_setxattr(struct dentry *d, const char *name, { if (strcmp(name, "") == 0) return -EINVAL; - return __ubifs_setxattr(d->d_inode, XATTR_NAME_SELINUX, value, + return __ubifs_setxattr(d->d_inode, name, value, size, flags); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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