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2009-02-12LSM adapter functions.Kentaro Takeda
DAC's permissions and TOMOYO's permissions are not one-to-one mapping. Regarding DAC, there are "read", "write", "execute" permissions. Regarding TOMOYO, there are "allow_read", "allow_write", "allow_read/write", "allow_execute", "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir", "allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar", "allow_truncate", "allow_symlink", "allow_rewrite", "allow_link", "allow_rename" permissions. +----------------------------------+----------------------------------+ | requested operation | required TOMOYO's permission | +----------------------------------+----------------------------------+ | sys_open(O_RDONLY) | allow_read | +----------------------------------+----------------------------------+ | sys_open(O_WRONLY) | allow_write | +----------------------------------+----------------------------------+ | sys_open(O_RDWR) | allow_read/write | +----------------------------------+----------------------------------+ | open_exec() from do_execve() | allow_execute | +----------------------------------+----------------------------------+ | open_exec() from !do_execve() | allow_read | +----------------------------------+----------------------------------+ | sys_read() | (none) | +----------------------------------+----------------------------------+ | sys_write() | (none) | +----------------------------------+----------------------------------+ | sys_mmap() | (none) | +----------------------------------+----------------------------------+ | sys_uselib() | allow_read | +----------------------------------+----------------------------------+ | sys_open(O_CREAT) | allow_create | +----------------------------------+----------------------------------+ | sys_open(O_TRUNC) | allow_truncate | +----------------------------------+----------------------------------+ | sys_truncate() | allow_truncate | +----------------------------------+----------------------------------+ | sys_ftruncate() | allow_truncate | +----------------------------------+----------------------------------+ | sys_open() without O_APPEND | allow_rewrite | +----------------------------------+----------------------------------+ | setfl() without O_APPEND | allow_rewrite | +----------------------------------+----------------------------------+ | sys_sysctl() for writing | allow_write | +----------------------------------+----------------------------------+ | sys_sysctl() for reading | allow_read | +----------------------------------+----------------------------------+ | sys_unlink() | allow_unlink | +----------------------------------+----------------------------------+ | sys_mknod(S_IFREG) | allow_create | +----------------------------------+----------------------------------+ | sys_mknod(0) | allow_create | +----------------------------------+----------------------------------+ | sys_mknod(S_IFIFO) | allow_mkfifo | +----------------------------------+----------------------------------+ | sys_mknod(S_IFSOCK) | allow_mksock | +----------------------------------+----------------------------------+ | sys_bind(AF_UNIX) | allow_mksock | +----------------------------------+----------------------------------+ | sys_mknod(S_IFBLK) | allow_mkblock | +----------------------------------+----------------------------------+ | sys_mknod(S_IFCHR) | allow_mkchar | +----------------------------------+----------------------------------+ | sys_symlink() | allow_symlink | +----------------------------------+----------------------------------+ | sys_mkdir() | allow_mkdir | +----------------------------------+----------------------------------+ | sys_rmdir() | allow_rmdir | +----------------------------------+----------------------------------+ | sys_link() | allow_link | +----------------------------------+----------------------------------+ | sys_rename() | allow_rename | +----------------------------------+----------------------------------+ TOMOYO requires "allow_execute" permission of a pathname passed to do_execve() but does not require "allow_read" permission of that pathname. Let's consider 3 patterns (statically linked, dynamically linked, shell script). This description is to some degree simplified. $ cat hello.c #include <stdio.h> int main() { printf("Hello\n"); return 0; } $ cat hello.sh #! /bin/sh echo "Hello" $ gcc -static -o hello-static hello.c $ gcc -o hello-dynamic hello.c $ chmod 755 hello.sh Case 1 -- Executing hello-static from bash. (1) The bash process calls fork() and the child process requests do_execve("hello-static"). (2) The kernel checks "allow_execute hello-static" from "bash" domain. (3) The kernel calculates "bash hello-static" as the domain to transit to. (4) The kernel overwrites the child process by "hello-static". (5) The child process transits to "bash hello-static" domain. (6) The "hello-static" starts and finishes. Case 2 -- Executing hello-dynamic from bash. (1) The bash process calls fork() and the child process requests do_execve("hello-dynamic"). (2) The kernel checks "allow_execute hello-dynamic" from "bash" domain. (3) The kernel calculates "bash hello-dynamic" as the domain to transit to. (4) The kernel checks "allow_read ld-linux.so" from "bash hello-dynamic" domain. I think permission to access ld-linux.so should be charged hello-dynamic program, for "hello-dynamic needs ld-linux.so" is not a fault of bash program. (5) The kernel overwrites the child process by "hello-dynamic". (6) The child process transits to "bash hello-dynamic" domain. (7) The "hello-dynamic" starts and finishes. Case 3 -- Executing hello.sh from bash. (1) The bash process calls fork() and the child process requests do_execve("hello.sh"). (2) The kernel checks "allow_execute hello.sh" from "bash" domain. (3) The kernel calculates "bash hello.sh" as the domain to transit to. (4) The kernel checks "allow_read /bin/sh" from "bash hello.sh" domain. I think permission to access /bin/sh should be charged hello.sh program, for "hello.sh needs /bin/sh" is not a fault of bash program. (5) The kernel overwrites the child process by "/bin/sh". (6) The child process transits to "bash hello.sh" domain. (7) The "/bin/sh" requests open("hello.sh"). (8) The kernel checks "allow_read hello.sh" from "bash hello.sh" domain. (9) The "/bin/sh" starts and finishes. Whether a file is interpreted as a program or not depends on an application. The kernel cannot know whether the file is interpreted as a program or not. Thus, TOMOYO treats "hello-static" "hello-dynamic" "ld-linux.so" "hello.sh" "/bin/sh" equally as merely files; no distinction between executable and non-executable. Therefore, TOMOYO doesn't check DAC's execute permission. TOMOYO checks "allow_read" permission instead. Calling do_execve() is a bold gesture that an old program's instance (i.e. current process) is ready to be overwritten by a new program and is ready to transfer control to the new program. To split purview of programs, TOMOYO requires "allow_execute" permission of the new program against the old program's instance and performs domain transition. If do_execve() succeeds, the old program is no longer responsible against the consequence of the new program's behavior. Only the new program is responsible for all consequences. But TOMOYO doesn't require "allow_read" permission of the new program. If TOMOYO requires "allow_read" permission of the new program, TOMOYO will allow an attacker (who hijacked the old program's instance) to open the new program and steal data from the new program. Requiring "allow_read" permission will widen purview of the old program. Not requiring "allow_read" permission of the new program against the old program's instance is my design for reducing purview of the old program. To be able to know whether the current process is in do_execve() or not, I want to add in_execve flag to "task_struct". Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12Domain transition handler.Kentaro Takeda
This file controls domain creation/deletion/transition. Every process belongs to a domain in TOMOYO Linux. Domain transition occurs when execve(2) is called and the domain is expressed as 'process invocation history', such as '<kernel> /sbin/init /etc/init.d/rc'. Domain information is stored in current->cred->security field. Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12File operation restriction part.Kentaro Takeda
This file controls file related operations of TOMOYO Linux. tomoyo/tomoyo.c calls the following six functions in this file. Each function handles the following access types. * tomoyo_check_file_perm sysctl()'s "read" and "write". * tomoyo_check_exec_perm "execute". * tomoyo_check_open_permission open(2) for "read" and "write". * tomoyo_check_1path_perm "create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock", "mkblock", "mkchar", "truncate" and "symlink". * tomoyo_check_2path_perm "rename" and "unlink". * tomoyo_check_rewrite_permission "rewrite". ("rewrite" are operations which may lose already recorded data of a file, i.e. open(!O_APPEND) || open(O_TRUNC) || truncate() || ftruncate()) The functions which actually checks ACLs are the following three functions. Each function handles the following access types. ACL directive is expressed by "allow_<access type>". * tomoyo_check_file_acl Open() operation and execve() operation. ("read", "write", "read/write" and "execute") * tomoyo_check_single_write_acl Directory modification operations with 1 pathname. ("create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock", "mkblock", "mkchar", "truncate", "symlink" and "rewrite") * tomoyo_check_double_write_acl Directory modification operations with 2 pathname. ("link" and "rename") Also, this file contains handlers of some utility directives for file related operations. * "allow_read": specifies globally (for all domains) readable files. * "path_group": specifies pathname macro. * "deny_rewrite": restricts rewrite operation. Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12Common functions for TOMOYO Linux.Kentaro Takeda
This file contains common functions (e.g. policy I/O, pattern matching). -------------------- About pattern matching -------------------- Since TOMOYO Linux is a name based access control, TOMOYO Linux seriously considers "safe" string representation. TOMOYO Linux's string manipulation functions make reviewers feel crazy, but there are reasons why TOMOYO Linux needs its own string manipulation functions. ----- Part 1 : preconditions ----- People definitely want to use wild card. To support pattern matching, we have to support wild card characters. In a typical Linux system, filenames are likely consists of only alphabets, numbers, and some characters (e.g. + - ~ . / ). But theoretically, the Linux kernel accepts all characters but NUL character (which is used as a terminator of a string). Some Linux systems can have filenames which contain * ? ** etc. Therefore, we have to somehow modify string so that we can distinguish wild card characters and normal characters. It might be possible for some application's configuration files to restrict acceptable characters. It is impossible for kernel to restrict acceptable characters. We can't accept approaches which will cause troubles for applications. ----- Part 2 : commonly used approaches ----- Text formatted strings separated by space character (0x20) and new line character (0x0A) is more preferable for users over array of NUL-terminated string. Thus, people use text formatted configuration files separated by space character and new line. We sometimes need to handle non-printable characters. Thus, people use \ character (0x5C) as escape character and represent non-printable characters using octal or hexadecimal format. At this point, we remind (at least) 3 approaches. (1) Shell glob style expression (2) POSIX regular expression (UNIX style regular expression) (3) Maverick wild card expression On the surface, (1) and (2) sound good choices. But they have a big pitfall. All meta-characters in (1) and (2) are legal characters for representing a pathname, and users easily write incorrect expression. What is worse, users unlikely notice incorrect expressions because characters used for regular pathnames unlikely contain meta-characters. This incorrect use of meta-characters in pathname representation reveals vulnerability (e.g. unexpected results) only when irregular pathname is specified. The authors of TOMOYO Linux think that approaches which adds some character for interpreting meta-characters as normal characters (i.e. (1) and (2)) are not suitable for security use. Therefore, the authors of TOMOYO Linux propose (3). ----- Part 3: consideration points ----- We need to solve encoding problem. A single character can be represented in several ways using encodings. For Japanese language, there are "ShiftJIS", "ISO-2022-JP", "EUC-JP", "UTF-8" and more. Some languages (e.g. Japanese language) supports multi-byte characters (where a single character is represented using several bytes). Some multi-byte characters may match the escape character. For Japanese language, some characters in "ShiftJIS" encoding match \ character, and bothering Web's CGI developers. It is important that the kernel string is not bothered by encoding problem. Linus said, "I really would expect that kernel strings don't have an encoding. They're just C strings: a NUL-terminated stream of bytes." http://lkml.org/lkml/2007/11/6/142 Yes. The kernel strings are just C strings. We are talking about how to store and carry "kernel strings" safely. If we store "kernel string" into policy file as-is, the "kernel string" will be interpreted differently depending on application's encoding settings. One application may interpret "kernel string" as "UTF-8", another application may interpret "kernel string" as "ShiftJIS". Therefore, we propose to represent strings using ASCII encoding. In this way, we are no longer bothered by encoding problems. We need to avoid information loss caused by display. It is difficult to input and display non-printable characters, but we have to be able to handle such characters because the kernel string is a C string. If we use only ASCII printable characters (from 0x21 to 0x7E) and space character (0x20) and new line character (0x0A), it is easy to input from keyboard and display on all terminals which is running Linux. Therefore, we propose to represent strings using only characters which value is one of "from 0x21 to 0x7E", "0x20", "0x0A". We need to consider ease of splitting strings from a line. If we use an approach which uses "\ " for representing a space character within a string, we have to count the string from the beginning to check whether this space character is accompanied with \ character or not. As a result, we cannot monotonically split a line using space character. If we use an approach which uses "\040" for representing a space character within a string, we can monotonically split a line using space character. If we use an approach which uses NUL character as a delimiter, we cannot use string manipulation functions for splitting strings from a line. Therefore, we propose that we represent space character as "\040". We need to avoid wrong designations (incorrect use of special characters). Not all users can understand and utilize POSIX's regular expressions correctly and perfectly. If a character acts as a wild card by default, the user will get unexpected result if that user didn't know the meaning of that character. Therefore, we propose that all characters but \ character act as a normal character and let the user add \ character to make a character act as a wild card. In this way, users needn't to know all wild card characters beforehand. They can learn when they encountered an unseen wild card character for their first time. ----- Part 4: supported wild card expressions ----- At this point, we have wild card expressions listed below. +-----------+--------------------------------------------------------------+ | Wild card | Meaning and example | +-----------+--------------------------------------------------------------+ | \* | More than or equals to 0 character other than '/'. | | | /var/log/samba/\* | +-----------+--------------------------------------------------------------+ | \@ | More than or equals to 0 character other than '/' or '.'. | | | /var/www/html/\@.html | +-----------+--------------------------------------------------------------+ | \? | 1 byte character other than '/'. | | | /tmp/mail.\?\?\?\?\?\? | +-----------+--------------------------------------------------------------+ | \$ | More than or equals to 1 decimal digit. | | | /proc/\$/cmdline | +-----------+--------------------------------------------------------------+ | \+ | 1 decimal digit. | | | /var/tmp/my_work.\+ | +-----------+--------------------------------------------------------------+ | \X | More than or equals to 1 hexadecimal digit. | | | /var/tmp/my-work.\X | +-----------+--------------------------------------------------------------+ | \x | 1 hexadecimal digit. | | | /tmp/my-work.\x | +-----------+--------------------------------------------------------------+ | \A | More than or equals to 1 alphabet character. | | | /var/log/my-work/\$-\A-\$.log | +-----------+--------------------------------------------------------------+ | \a | 1 alphabet character. | | | /home/users/\a/\*/public_html/\*.html | +-----------+--------------------------------------------------------------+ | \- | Pathname subtraction operator. | | | +---------------------+------------------------------------+ | | | | Example | Meaning | | | | +---------------------+------------------------------------+ | | | | /etc/\* | All files in /etc/ directory. | | | | +---------------------+------------------------------------+ | | | | /etc/\*\-\*shadow\* | /etc/\* other than /etc/\*shadow\* | | | | +---------------------+------------------------------------+ | | | | /\*\-proc\-sys/ | /\*/ other than /proc/ /sys/ | | | | +---------------------+------------------------------------+ | +-----------+--------------------------------------------------------------+ +----------------+---------------------------------------------------------+ | Representation | Meaning and example | +----------------+---------------------------------------------------------+ | \\ | backslash character itself. | +----------------+---------------------------------------------------------+ | \ooo | 1 byte character. | | | ooo is 001 <= ooo <= 040 || 177 <= ooo <= 377. | | | | | | \040 for space character. | | | \177 for del character. | | | | +----------------+---------------------------------------------------------+ ----- Part 5: Advantages ----- We can obtain extensibility. Since our proposed approach adds \ to a character to interpret as a wild card, we can introduce new wild card in future while maintaining backward compatibility. We can process monotonically. Since our proposed approach separates strings using a space character, we can split strings using existing string manipulation functions. We can reliably analyze access logs. It is guaranteed that a string doesn't contain space character (0x20) and new line character (0x0A). It is guaranteed that a string won't be converted by FTP and won't be damaged by a terminal's settings. It is guaranteed that a string won't be affected by encoding converters (except encodings which insert NUL character (e.g. UTF-16)). ----- Part 6: conclusion ----- TOMOYO Linux is using its own encoding with reasons described above. There is a disadvantage that we need to introduce a series of new string manipulation functions. But TOMOYO Linux's encoding is useful for all users (including audit and AppArmor) who want to perform pattern matching and safely exchange string information between the kernel and the userspace. -------------------- About policy interface -------------------- TOMOYO Linux creates the following files on securityfs (normally mounted on /sys/kernel/security) as interfaces between kernel and userspace. These files are for TOMOYO Linux management tools *only*, not for general programs. * profile * exception_policy * domain_policy * manager * meminfo * self_domain * version * .domain_status * .process_status ** /sys/kernel/security/tomoyo/profile ** This file is used to read or write profiles. "profile" means a running mode of process. A profile lists up functions and their modes in "$number-$variable=$value" format. The $number is profile number between 0 and 255. Each domain is assigned one profile. To assign profile to domains, use "ccs-setprofile" or "ccs-editpolicy" or "ccs-loadpolicy" commands. (Example) [root@tomoyo]# cat /sys/kernel/security/tomoyo/profile 0-COMMENT=-----Disabled Mode----- 0-MAC_FOR_FILE=disabled 0-MAX_ACCEPT_ENTRY=2048 0-TOMOYO_VERBOSE=disabled 1-COMMENT=-----Learning Mode----- 1-MAC_FOR_FILE=learning 1-MAX_ACCEPT_ENTRY=2048 1-TOMOYO_VERBOSE=disabled 2-COMMENT=-----Permissive Mode----- 2-MAC_FOR_FILE=permissive 2-MAX_ACCEPT_ENTRY=2048 2-TOMOYO_VERBOSE=enabled 3-COMMENT=-----Enforcing Mode----- 3-MAC_FOR_FILE=enforcing 3-MAX_ACCEPT_ENTRY=2048 3-TOMOYO_VERBOSE=enabled - MAC_FOR_FILE: Specifies access control level regarding file access requests. - MAX_ACCEPT_ENTRY: Limits the max number of ACL entries that are automatically appended during learning mode. Default is 2048. - TOMOYO_VERBOSE: Specifies whether to print domain policy violation messages or not. ** /sys/kernel/security/tomoyo/manager ** This file is used to read or append the list of programs or domains that can write to /sys/kernel/security/tomoyo interface. By default, only processes with both UID = 0 and EUID = 0 can modify policy via /sys/kernel/security/tomoyo interface. You can use keyword "manage_by_non_root" to allow policy modification by non root user. (Example) [root@tomoyo]# cat /sys/kernel/security/tomoyo/manager /usr/lib/ccs/loadpolicy /usr/lib/ccs/editpolicy /usr/lib/ccs/setlevel /usr/lib/ccs/setprofile /usr/lib/ccs/ld-watch /usr/lib/ccs/ccs-queryd ** /sys/kernel/security/tomoyo/exception_policy ** This file is used to read and write system global settings. Each line has a directive and operand pair. Directives are listed below. - initialize_domain: To initialize domain transition when specific program is executed, use initialize_domain directive. * initialize_domain "program" from "domain" * initialize_domain "program" from "the last program part of domain" * initialize_domain "program" If the part "from" and after is not given, the entry is applied to all domain. If the "domain" doesn't start with "<kernel>", the entry is applied to all domain whose domainname ends with "the last program part of domain". This directive is intended to aggregate domain transitions for daemon program and program that are invoked by the kernel on demand, by transiting to different domain. - keep_domain To prevent domain transition when program is executed from specific domain, use keep_domain directive. * keep_domain "program" from "domain" * keep_domain "program" from "the last program part of domain" * keep_domain "domain" * keep_domain "the last program part of domain" If the part "from" and before is not given, this entry is applied to all program. If the "domain" doesn't start with "<kernel>", the entry is applied to all domain whose domainname ends with "the last program part of domain". This directive is intended to reduce total number of domains and memory usage by suppressing unneeded domain transitions. To declare domain keepers, use keep_domain directive followed by domain definition. Any process that belongs to any domain declared with this directive, the process stays at the same domain unless any program registered with initialize_domain directive is executed. In order to control domain transition in detail, you can use no_keep_domain/no_initialize_domain keywrods. - alias: To allow executing programs using the name of symbolic links, use alias keyword followed by dereferenced pathname and reference pathname. For example, /sbin/pidof is a symbolic link to /sbin/killall5 . In normal case, if /sbin/pidof is executed, the domain is defined as if /sbin/killall5 is executed. By specifying "alias /sbin/killall5 /sbin/pidof", you can run /sbin/pidof in the domain for /sbin/pidof . (Example) alias /sbin/killall5 /sbin/pidof - allow_read: To grant unconditionally readable permissions, use allow_read keyword followed by canonicalized file. This keyword is intended to reduce size of domain policy by granting read access to library files such as GLIBC and locale files. Exception is, if ignore_global_allow_read keyword is given to a domain, entries specified by this keyword are ignored. (Example) allow_read /lib/libc-2.5.so - file_pattern: To declare pathname pattern, use file_pattern keyword followed by pathname pattern. The pathname pattern must be a canonicalized Pathname. This keyword is not applicable to neither granting execute permissions nor domain definitions. For example, canonicalized pathname that contains a process ID (i.e. /proc/PID/ files) needs to be grouped in order to make access control work well. (Example) file_pattern /proc/\$/cmdline - path_group To declare pathname group, use path_group keyword followed by name of the group and pathname pattern. For example, if you want to group all files under home directory, you can define path_group HOME-DIR-FILE /home/\*/\* path_group HOME-DIR-FILE /home/\*/\*/\* path_group HOME-DIR-FILE /home/\*/\*/\*/\* in the exception policy and use like allow_read @HOME-DIR-FILE to grant file access permission. - deny_rewrite: To deny overwriting already written contents of file (such as log files) by default, use deny_rewrite keyword followed by pathname pattern. Files whose pathname match the patterns are not permitted to open for writing without append mode or truncate unless the pathnames are explicitly granted using allow_rewrite keyword in domain policy. (Example) deny_rewrite /var/log/\* - aggregator To deal multiple programs as a single program, use aggregator keyword followed by name of original program and aggregated program. This keyword is intended to aggregate similar programs. For example, /usr/bin/tac and /bin/cat are similar. By specifying "aggregator /usr/bin/tac /bin/cat", you can run /usr/bin/tac in the domain for /bin/cat . For example, /usr/sbin/logrotate for Fedora Core 3 generates programs like /tmp/logrotate.\?\?\?\?\?\? and run them, but TOMOYO Linux doesn't allow using patterns for granting execute permission and defining domains. By specifying "aggregator /tmp/logrotate.\?\?\?\?\?\? /tmp/logrotate.tmp", you can run /tmp/logrotate.\?\?\?\?\?\? as if /tmp/logrotate.tmp is running. ** /sys/kernel/security/tomoyo/domain_policy ** This file contains definition of all domains and permissions that are granted to each domain. Lines from the next line to a domain definition ( any lines starting with "<kernel>") to the previous line to the next domain definitions are interpreted as access permissions for that domain. ** /sys/kernel/security/tomoyo/meminfo ** This file is to show the total RAM used to keep policy in the kernel by TOMOYO Linux in bytes. (Example) [root@tomoyo]# cat /sys/kernel/security/tomoyo/meminfo Shared: 61440 Private: 69632 Dynamic: 768 Total: 131840 You can set memory quota by writing to this file. (Example) [root@tomoyo]# echo Shared: 2097152 > /sys/kernel/security/tomoyo/meminfo [root@tomoyo]# echo Private: 2097152 > /sys/kernel/security/tomoyo/meminfo ** /sys/kernel/security/tomoyo/self_domain ** This file is to show the name of domain the caller process belongs to. (Example) [root@etch]# cat /sys/kernel/security/tomoyo/self_domain <kernel> /usr/sbin/sshd /bin/zsh /bin/cat ** /sys/kernel/security/tomoyo/version ** This file is used for getting TOMOYO Linux's version. (Example) [root@etch]# cat /sys/kernel/security/tomoyo/version 2.2.0-pre ** /sys/kernel/security/tomoyo/.domain_status ** This is a view (of a DBMS) that contains only profile number and domainnames of domain so that "ccs-setprofile" command can do line-oriented processing easily. ** /sys/kernel/security/tomoyo/.process_status ** This file is used by "ccs-ccstree" command to show "list of processes currently running" and "domains which each process belongs to" and "profile number which the domain is currently assigned" like "pstree" command. This file is writable by programs that aren't registered as policy manager. Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12Memory and pathname management functions.Kentaro Takeda
TOMOYO Linux performs pathname based access control. To remove factors that make pathname based access control difficult (e.g. symbolic links, "..", "//" etc.), TOMOYO Linux derives realpath of requested pathname from "struct dentry" and "struct vfsmount". The maximum length of string data is limited to 4000 including trailing '\0'. Since TOMOYO Linux uses '\ooo' style representation for non ASCII printable characters, maybe TOMOYO Linux should be able to support 16336 (which means (NAME_MAX * (PATH_MAX / (NAME_MAX + 1)) * 4 + (PATH_MAX / (NAME_MAX + 1))) including trailing '\0'), but I think 4000 is enough for practical use. TOMOYO uses only 0x21 - 0x7E (as printable characters) and 0x20 (as word delimiter) and 0x0A (as line delimiter). 0x01 - 0x20 and 0x80 - 0xFF is handled in \ooo style representation. The reason to use \ooo is to guarantee that "%s" won't damage logs. Userland program can request open("/tmp/file granted.\nAccess /tmp/file ", O_WRONLY | O_CREAT, 0600) and logging such crazy pathname using "Access %s denied.\n" format will cause "fabrication of logs" like Access /tmp/file granted. Access /tmp/file denied. TOMOYO converts such characters to \ooo so that the logs will become Access /tmp/file\040granted.\012Access\040/tmp/file denied. and the administrator can read the logs safely using /bin/cat . Likewise, a crazy request like open("/tmp/\x01\x02\x03\x04\x05\x06\x07\x08\x09", O_WRONLY | O_CREAT, 0600) will be processed safely by converting to Access /tmp/\001\002\003\004\005\006\007\010\011 denied. Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12integrity: audit updateMimi Zohar
Based on discussions on linux-audit, as per Steve Grubb's request http://lkml.org/lkml/2009/2/6/269, the following changes were made: - forced audit result to be either 0 or 1. - made template names const - Added new stand-alone message type: AUDIT_INTEGRITY_RULE Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Steve Grubb <sgrubb@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-06Merge branch 'master' into nextJames Morris
Conflicts: fs/namei.c Manually merged per: diff --cc fs/namei.c index 734f2b5,bbc15c2..0000000 --- a/fs/namei.c +++ b/fs/namei.c @@@ -860,9 -848,8 +849,10 @@@ static int __link_path_walk(const char nd->flags |= LOOKUP_CONTINUE; err = exec_permission_lite(inode); if (err == -EAGAIN) - err = vfs_permission(nd, MAY_EXEC); + err = inode_permission(nd->path.dentry->d_inode, + MAY_EXEC); + if (!err) + err = ima_path_check(&nd->path, MAY_EXEC); if (err) break; @@@ -1525,14 -1506,9 +1509,14 @@@ int may_open(struct path *path, int acc flag &= ~O_TRUNC; } - error = vfs_permission(nd, acc_mode); + error = inode_permission(inode, acc_mode); if (error) return error; + - error = ima_path_check(&nd->path, ++ error = ima_path_check(path, + acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC)); + if (error) + return error; /* * An append-only file must be opened in append mode for writing. */ Signed-off-by: James Morris <jmorris@namei.org>
2009-02-06IMA: fix ima_delete_rules() definitionJames Morris
Fix ima_delete_rules() definition so sparse doesn't complain. Signed-off-by: James Morris <jmorris@namei.org>
2009-02-06Integrity: IMA file free imbalanceMimi Zohar
The number of calls to ima_path_check()/ima_file_free() should be balanced. An extra call to fput(), indicates the file could have been accessed without first being measured. Although f_count is incremented/decremented in places other than fget/fput, like fget_light/fput_light and get_file, the current task must already hold a file refcnt. The call to __fput() is delayed until the refcnt becomes 0, resulting in ima_file_free() flagging any changes. - add hook to increment opencount for IPC shared memory(SYSV), shmat files, and /dev/zero - moved NULL iint test in opencount_get() Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-06integrity: IMA policy openMimi Zohar
Sequentialize access to the policy file - permit multiple attempts to replace default policy with a valid policy Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-06integrity: IMA policyMimi Zohar
Support for a user loadable policy through securityfs with support for LSM specific policy data. - free invalid rule in ima_parse_add_rule() Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-06integrity: IMA displayMimi Zohar
Make the measurement lists available through securityfs. - removed test for NULL return code from securityfs_create_file/dir Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-06integrity: IMA as an integrity service providerMimi Zohar
IMA provides hardware (TPM) based measurement and attestation for file measurements. As the Trusted Computing (TPM) model requires, IMA measures all files before they are accessed in any way (on the integrity_bprm_check, integrity_path_check and integrity_file_mmap hooks), and commits the measurements to the TPM. Once added to the TPM, measurements can not be removed. In addition, IMA maintains a list of these file measurements, which can be used to validate the aggregate value stored in the TPM. The TPM can sign these measurements, and thus the system can prove, to itself and to a third party, the system's integrity in a way that cannot be circumvented by malicious or compromised software. - alloc ima_template_entry before calling ima_store_template() - log ima_add_boot_aggregate() failure - removed unused IMA_TEMPLATE_NAME_LEN - replaced hard coded string length with #define name Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-03securityfs: fix long-broken securityfs_create_file commentSerge E. Hallyn
If there is an error creating a file through securityfs_create_file, NULL is not returned, rather the error is propagated. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-02selinux: remove hooks which simply defer to capabilitiesJames Morris
Remove SELinux hooks which do nothing except defer to the capabilites hooks (or in one case, replicates the function). Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2009-01-30selinux: remove secondary ops call to shm_shmatJames Morris
Remove secondary ops call to shm_shmat, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to unix_stream_connectJames Morris
Remove secondary ops call to unix_stream_connect, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to task_killJames Morris
Remove secondary ops call to task_kill, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to task_setrlimitJames Morris
Remove secondary ops call to task_setrlimit, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove unused cred_commit hookJames Morris
Remove unused cred_commit hook from SELinux. This currently calls into the capabilities hook, which is a noop. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to task_createJames Morris
Remove secondary ops call to task_create, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to file_mprotectJames Morris
Remove secondary ops call to file_mprotect, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to inode_setattrJames Morris
Remove secondary ops call to inode_setattr, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to inode_permissionJames Morris
Remove secondary ops call to inode_permission, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to inode_follow_linkJames Morris
Remove secondary ops call to inode_follow_link, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to inode_mknodJames Morris
Remove secondary ops call to inode_mknod, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to inode_unlinkJames Morris
Remove secondary ops call to inode_unlink, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to inode_linkJames Morris
Remove secondary ops call to inode_link, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to sb_umountJames Morris
Remove secondary ops call to sb_umount, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to sb_mountJames Morris
Remove secondary ops call to sb_mount, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to bprm_committed_credsJames Morris
Remove secondary ops call to bprm_committed_creds, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove secondary ops call to bprm_committing_credsJames Morris
Remove secondary ops call to bprm_committing_creds, which is a noop in capabilities. Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-30selinux: remove unused bprm_check_security hookJames Morris
Remove unused bprm_check_security hook from SELinux. This currently calls into the capabilities hook, which is a noop. Acked-by: Eric Paris <eparis@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-27smackfs load append mode fixCasey Schaufler
Given just how hard it is to find the code that uses MAY_APPEND it's probably not a big surprise that this went unnoticed for so long. The Smack rules loading code is incorrectly setting the MAY_READ bit when MAY_APPEND is requested. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-19SELinux: Unify context mount and genfs behaviorDavid P. Quigley
Context mounts and genfs labeled file systems behave differently with respect to setting file system labels. This patch brings genfs labeled file systems in line with context mounts in that setxattr calls to them should return EOPNOTSUPP and fscreate calls will be ignored. Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@macbook.localdomain>
2009-01-19SELinux: Add new security mount option to indicate security label support.David P. Quigley
There is no easy way to tell if a file system supports SELinux security labeling. Because of this a new flag is being added to the super block security structure to indicate that the particular super block supports labeling. This flag is set for file systems using the xattr, task, and transition labeling methods unless that behavior is overridden by context mounts. Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@macbook.localdomain>
2009-01-19SELinux: Condense super block security structure flags and cleanup necessary ↵David P. Quigley
code. The super block security structure currently has three fields for what are essentially flags. The flags field is used for mount options while two other char fields are used for initialization and proc flags. These latter two fields are essentially bit fields since the only used values are 0 and 1. These fields have been collapsed into the flags field and new bit masks have been added for them. The code is also fixed to work with these new flags. Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@macbook.localdomain>
2009-01-17security: introduce missing kfreeVegard Nossum
Plug this leak. Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: <stable@kernel.org> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-14[CVE-2009-0029] System call wrappers part 28Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14[CVE-2009-0029] System call wrappers part 27Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-08remove lots of double-semicolonsFernando Carrijo
Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Theodore Ts'o <tytso@mit.edu> Acked-by: Mark Fasheh <mfasheh@suse.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08devices cgroup: allow mkfifoSerge E. Hallyn
The devcgroup_inode_permission() hook in the devices whitelist cgroup has always bypassed access checks on fifos. But the mknod hook did not. The devices whitelist is only about block and char devices, and fifos can't even be added to the whitelist, so fifos can't be created at all except by tasks which have 'a' in their whitelist (meaning they have access to all devices). Fix the behavior by bypassing access checks to mkfifo. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Paul Menage <menage@google.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: James Morris <jmorris@namei.org> Reported-by: Daniel Lezcano <dlezcano@fr.ibm.com> Cc: <stable@kernel.org> [2.6.27.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08devcgroup: use list_for_each_entry_rcu()Lai Jiangshan
We should use list_for_each_entry_rcu in RCU read site. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-07Merge branch 'next' into for-linusJames Morris
2009-01-07CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #3]David Howells
Fix a regression in cap_capable() due to: commit 3b11a1decef07c19443d24ae926982bc8ec9f4c0 Author: David Howells <dhowells@redhat.com> Date: Fri Nov 14 10:39:26 2008 +1100 CRED: Differentiate objective and effective subjective credentials on a task The problem is that the above patch allows a process to have two sets of credentials, and for the most part uses the subjective credentials when accessing current's creds. There is, however, one exception: cap_capable(), and thus capable(), uses the real/objective credentials of the target task, whether or not it is the current task. Ordinarily this doesn't matter, since usually the two cred pointers in current point to the same set of creds. However, sys_faccessat() makes use of this facility to override the credentials of the calling process to make its test, without affecting the creds as seen from other processes. One of the things sys_faccessat() does is to make an adjustment to the effective capabilities mask, which cap_capable(), as it stands, then ignores. The affected capability check is in generic_permission(): if (!(mask & MAY_EXEC) || execute_ok(inode)) if (capable(CAP_DAC_OVERRIDE)) return 0; This change passes the set of credentials to be tested down into the commoncap and SELinux code. The security functions called by capable() and has_capability() select the appropriate set of credentials from the process being checked. This can be tested by compiling the following program from the XFS testsuite: /* * t_access_root.c - trivial test program to show permission bug. * * Written by Michael Kerrisk - copyright ownership not pursued. * Sourced from: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-10/6030.html */ #include <limits.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <sys/stat.h> #define UID 500 #define GID 100 #define PERM 0 #define TESTPATH "/tmp/t_access" static void errExit(char *msg) { perror(msg); exit(EXIT_FAILURE); } /* errExit */ static void accessTest(char *file, int mask, char *mstr) { printf("access(%s, %s) returns %d\n", file, mstr, access(file, mask)); } /* accessTest */ int main(int argc, char *argv[]) { int fd, perm, uid, gid; char *testpath; char cmd[PATH_MAX + 20]; testpath = (argc > 1) ? argv[1] : TESTPATH; perm = (argc > 2) ? strtoul(argv[2], NULL, 8) : PERM; uid = (argc > 3) ? atoi(argv[3]) : UID; gid = (argc > 4) ? atoi(argv[4]) : GID; unlink(testpath); fd = open(testpath, O_RDWR | O_CREAT, 0); if (fd == -1) errExit("open"); if (fchown(fd, uid, gid) == -1) errExit("fchown"); if (fchmod(fd, perm) == -1) errExit("fchmod"); close(fd); snprintf(cmd, sizeof(cmd), "ls -l %s", testpath); system(cmd); if (seteuid(uid) == -1) errExit("seteuid"); accessTest(testpath, 0, "0"); accessTest(testpath, R_OK, "R_OK"); accessTest(testpath, W_OK, "W_OK"); accessTest(testpath, X_OK, "X_OK"); accessTest(testpath, R_OK | W_OK, "R_OK | W_OK"); accessTest(testpath, R_OK | X_OK, "R_OK | X_OK"); accessTest(testpath, W_OK | X_OK, "W_OK | X_OK"); accessTest(testpath, R_OK | W_OK | X_OK, "R_OK | W_OK | X_OK"); exit(EXIT_SUCCESS); } /* main */ This can be run against an Ext3 filesystem as well as against an XFS filesystem. If successful, it will show: [root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043 ---------- 1 dhowells dhowells 0 2008-12-31 03:00 /tmp/xxx access(/tmp/xxx, 0) returns 0 access(/tmp/xxx, R_OK) returns 0 access(/tmp/xxx, W_OK) returns 0 access(/tmp/xxx, X_OK) returns -1 access(/tmp/xxx, R_OK | W_OK) returns 0 access(/tmp/xxx, R_OK | X_OK) returns -1 access(/tmp/xxx, W_OK | X_OK) returns -1 access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1 If unsuccessful, it will show: [root@andromeda src]# ./t_access_root /tmp/xxx 0 4043 4043 ---------- 1 dhowells dhowells 0 2008-12-31 02:56 /tmp/xxx access(/tmp/xxx, 0) returns 0 access(/tmp/xxx, R_OK) returns -1 access(/tmp/xxx, W_OK) returns -1 access(/tmp/xxx, X_OK) returns -1 access(/tmp/xxx, R_OK | W_OK) returns -1 access(/tmp/xxx, R_OK | X_OK) returns -1 access(/tmp/xxx, W_OK | X_OK) returns -1 access(/tmp/xxx, R_OK | W_OK | X_OK) returns -1 I've also tested the fix with the SELinux and syscalls LTP testsuites. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: J. Bruce Fields <bfields@citi.umich.edu> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-07Revert "CRED: Fix regression in cap_capable() as shown up by sys_faccessat() ↵James Morris
[ver #2]" This reverts commit 14eaddc967b16017d4a1a24d2be6c28ecbe06ed8. David has a better version to come.
2009-01-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: inotify: fix type errors in interfaces fix breakage in reiserfs_new_inode() fix the treatment of jfs special inodes vfs: remove duplicate code in get_fs_type() add a vfs_fsync helper sys_execve and sys_uselib do not call into fsnotify zero i_uid/i_gid on inode allocation inode->i_op is never NULL ntfs: don't NULL i_op isofs check for NULL ->i_op in root directory is dead code affs: do not zero ->i_op kill suid bit only for regular files vfs: lseek(fd, 0, SEEK_CUR) race condition
2009-01-05zero i_uid/i_gid on inode allocationAl Viro
... and don't bother in callers. Don't bother with zeroing i_blocks, while we are at it - it's already been zeroed. i_mode is not worth the effort; it has no common default value. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05inode->i_op is never NULLAl Viro
We used to have rather schizophrenic set of checks for NULL ->i_op even though it had been eliminated years ago. You'd need to go out of your way to set it to NULL explicitly _and_ a bunch of code would die on such inodes anyway. After killing two remaining places that still did that bogosity, all that crap can go away. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-01-05SELinux: shrink sizeof av_inhert selinux_class_perm and contextEric Paris
I started playing with pahole today and decided to put it against the selinux structures. Found we could save a little bit of space on x86_64 (and no harm on i686) just reorganizing some structs. Object size changes: av_inherit: 24 -> 16 selinux_class_perm: 48 -> 40 context: 80 -> 72 Admittedly there aren't many of av_inherit or selinux_class_perm's in the kernel (33 and 1 respectively) But the change to the size of struct context reverberate out a bit. I can get some hard number if they are needed, but I don't see why they would be. We do change which cacheline context->len and context->str would be on, but I don't see that as a problem since we are clearly going to have to load both if the context is to be of any value. I've run with the patch and don't seem to be having any problems. An example of what's going on using struct av_inherit would be: form: to: struct av_inherit { struct av_inherit { u16 tclass; const char **common_pts; const char **common_pts; u32 common_base; u32 common_base; u16 tclass; }; (notice all I did was move u16 tclass to the end of the struct instead of the beginning) Memory layout before the change: struct av_inherit { u16 tclass; /* 2 */ /* 6 bytes hole */ const char** common_pts; /* 8 */ u32 common_base; /* 4 */ /* 4 byes padding */ /* size: 24, cachelines: 1 */ /* sum members: 14, holes: 1, sum holes: 6 */ /* padding: 4 */ }; Memory layout after the change: struct av_inherit { const char ** common_pts; /* 8 */ u32 common_base; /* 4 */ u16 tclass; /* 2 */ /* 2 bytes padding */ /* size: 16, cachelines: 1 */ /* sum members: 14, holes: 0, sum holes: 0 */ /* padding: 2 */ }; Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>