From 89d155ef62e5e0c10e4b37aaa5056f0beafe10e6 Mon Sep 17 00:00:00 2001 From: James Morris Date: Sun, 30 Oct 2005 14:59:21 -0800 Subject: [PATCH] SELinux: convert to kzalloc This patch converts SELinux code from kmalloc/memset to the new kazalloc unction. On i386, this results in a text saving of over 1K. Before: text data bss dec hex filename 86319 4642 15236 106197 19ed5 security/selinux/built-in.o After: text data bss dec hex filename 85278 4642 15236 105156 19ac4 security/selinux/built-in.o Signed-off-by: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 447a1e0f48cb..8cd33b2cd865 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -122,11 +122,10 @@ static int task_alloc_security(struct task_struct *task) { struct task_security_struct *tsec; - tsec = kmalloc(sizeof(struct task_security_struct), GFP_KERNEL); + tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); if (!tsec) return -ENOMEM; - memset(tsec, 0, sizeof(struct task_security_struct)); tsec->magic = SELINUX_MAGIC; tsec->task = task; tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED; @@ -151,11 +150,10 @@ static int inode_alloc_security(struct inode *inode) struct task_security_struct *tsec = current->security; struct inode_security_struct *isec; - isec = kmalloc(sizeof(struct inode_security_struct), GFP_KERNEL); + isec = kzalloc(sizeof(struct inode_security_struct), GFP_KERNEL); if (!isec) return -ENOMEM; - memset(isec, 0, sizeof(struct inode_security_struct)); init_MUTEX(&isec->sem); INIT_LIST_HEAD(&isec->list); isec->magic = SELINUX_MAGIC; @@ -193,11 +191,10 @@ static int file_alloc_security(struct file *file) struct task_security_struct *tsec = current->security; struct file_security_struct *fsec; - fsec = kmalloc(sizeof(struct file_security_struct), GFP_ATOMIC); + fsec = kzalloc(sizeof(struct file_security_struct), GFP_ATOMIC); if (!fsec) return -ENOMEM; - memset(fsec, 0, sizeof(struct file_security_struct)); fsec->magic = SELINUX_MAGIC; fsec->file = file; if (tsec && tsec->magic == SELINUX_MAGIC) { @@ -227,11 +224,10 @@ static int superblock_alloc_security(struct super_block *sb) { struct superblock_security_struct *sbsec; - sbsec = kmalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); + sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); if (!sbsec) return -ENOMEM; - memset(sbsec, 0, sizeof(struct superblock_security_struct)); init_MUTEX(&sbsec->sem); INIT_LIST_HEAD(&sbsec->list); INIT_LIST_HEAD(&sbsec->isec_head); @@ -269,11 +265,10 @@ static int sk_alloc_security(struct sock *sk, int family, gfp_t priority) if (family != PF_UNIX) return 0; - ssec = kmalloc(sizeof(*ssec), priority); + ssec = kzalloc(sizeof(*ssec), priority); if (!ssec) return -ENOMEM; - memset(ssec, 0, sizeof(*ssec)); ssec->magic = SELINUX_MAGIC; ssec->sk = sk; ssec->peer_sid = SECINITSID_UNLABELED; @@ -1483,11 +1478,10 @@ static int selinux_bprm_alloc_security(struct linux_binprm *bprm) { struct bprm_security_struct *bsec; - bsec = kmalloc(sizeof(struct bprm_security_struct), GFP_KERNEL); + bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL); if (!bsec) return -ENOMEM; - memset(bsec, 0, sizeof *bsec); bsec->magic = SELINUX_MAGIC; bsec->bprm = bprm; bsec->sid = SECINITSID_UNLABELED; @@ -3599,11 +3593,10 @@ static int ipc_alloc_security(struct task_struct *task, struct task_security_struct *tsec = task->security; struct ipc_security_struct *isec; - isec = kmalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); + isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); if (!isec) return -ENOMEM; - memset(isec, 0, sizeof(struct ipc_security_struct)); isec->magic = SELINUX_MAGIC; isec->sclass = sclass; isec->ipc_perm = perm; @@ -3631,11 +3624,10 @@ static int msg_msg_alloc_security(struct msg_msg *msg) { struct msg_security_struct *msec; - msec = kmalloc(sizeof(struct msg_security_struct), GFP_KERNEL); + msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL); if (!msec) return -ENOMEM; - memset(msec, 0, sizeof(struct msg_security_struct)); msec->magic = SELINUX_MAGIC; msec->msg = msg; msec->sid = SECINITSID_UNLABELED; -- cgit v1.2.3 From d381d8a9a08cac9824096213069159be17fd2e2f Mon Sep 17 00:00:00 2001 From: James Morris Date: Sun, 30 Oct 2005 14:59:22 -0800 Subject: [PATCH] SELinux: canonicalize getxattr() This patch allows SELinux to canonicalize the value returned from getxattr() via the security_inode_getsecurity() hook, which is called after the fs level getxattr() function. The purpose of this is to allow the in-core security context for an inode to override the on-disk value. This could happen in cases such as upgrading a system to a different labeling form (e.g. standard SELinux to MLS) without needing to do a full relabel of the filesystem. In such cases, we want getxattr() to return the canonical security context that the kernel is using rather than what is stored on disk. The implementation hooks into the inode_getsecurity(), adding another parameter to indicate the result of the preceding fs-level getxattr() call, so that SELinux knows whether to compare a value obtained from disk with the kernel value. We also now allow getxattr() to work for mountpoint labeled filesystems (i.e. mount with option context=foo_t), as we are able to return the kernel value to the user. Signed-off-by: James Morris Signed-off-by: Stephen Smalley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 46 ++++++++++++++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 14 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 8cd33b2cd865..d9ec85292e1c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2208,9 +2208,6 @@ static int selinux_inode_getxattr (struct dentry *dentry, char *name) struct inode *inode = dentry->d_inode; struct superblock_security_struct *sbsec = inode->i_sb->s_security; - if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT) - return -EOPNOTSUPP; - return dentry_has_perm(current, NULL, dentry, FILE__GETATTR); } @@ -2241,33 +2238,54 @@ static int selinux_inode_removexattr (struct dentry *dentry, char *name) return -EACCES; } -static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size) +/* + * Copy the in-core inode security context value to the user. If the + * getxattr() prior to this succeeded, check to see if we need to + * canonicalize the value to be finally returned to the user. + * + * Permission check is handled by selinux_inode_getxattr hook. + */ +static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size, int err) { struct inode_security_struct *isec = inode->i_security; char *context; unsigned len; int rc; - /* Permission check handled by selinux_inode_getxattr hook.*/ - - if (strcmp(name, XATTR_SELINUX_SUFFIX)) - return -EOPNOTSUPP; + if (strcmp(name, XATTR_SELINUX_SUFFIX)) { + rc = -EOPNOTSUPP; + goto out; + } rc = security_sid_to_context(isec->sid, &context, &len); if (rc) - return rc; + goto out; + /* Probe for required buffer size */ if (!buffer || !size) { - kfree(context); - return len; + rc = len; + goto out_free; } + if (size < len) { - kfree(context); - return -ERANGE; + rc = -ERANGE; + goto out_free; + } + + if (err > 0) { + if ((len == err) && !(memcmp(context, buffer, len))) { + /* Don't need to canonicalize value */ + rc = err; + goto out_free; + } + memset(buffer, 0, size); } memcpy(buffer, context, len); + rc = len; +out_free: kfree(context); - return len; +out: + return rc; } static int selinux_inode_setsecurity(struct inode *inode, const char *name, -- cgit v1.2.3 From ce4c2bd1a9dfebaefadc2d34b17c6f12101751be Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Sun, 30 Oct 2005 14:59:23 -0800 Subject: [PATCH] selinux-canonicalize-getxattr-fix security/selinux/hooks.c: In function `selinux_inode_getxattr': security/selinux/hooks.c:2193: warning: unused variable `sbsec' Cc: James Morris Cc: Stephen Smalley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index d9ec85292e1c..d50d7a782cf5 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2205,9 +2205,6 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, char *name, static int selinux_inode_getxattr (struct dentry *dentry, char *name) { - struct inode *inode = dentry->d_inode; - struct superblock_security_struct *sbsec = inode->i_sb->s_security; - return dentry_has_perm(current, NULL, dentry, FILE__GETATTR); } -- cgit v1.2.3 From 2f51201662b28dbf8c15fb7eb972bc51c6cc3fa5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 30 Oct 2005 15:02:16 -0800 Subject: [PATCH] reduce sizeof(struct file) Now that RCU applied on 'struct file' seems stable, we can place f_rcuhead in a memory location that is not anymore used at call_rcu(&f->f_rcuhead, file_free_rcu) time, to reduce the size of this critical kernel object. The trick I used is to move f_rcuhead and f_list in an union called f_u The callers are changed so that f_rcuhead becomes f_u.fu_rcuhead and f_list becomes f_u.f_list Signed-off-by: Eric Dumazet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index d50d7a782cf5..bb62838be496 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1609,7 +1609,7 @@ static inline void flush_unauthorized_files(struct files_struct * files) if (tty) { file_list_lock(); - file = list_entry(tty->tty_files.next, typeof(*file), f_list); + file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list); if (file) { /* Revalidate access to controlling tty. Use inode_has_perm on the tty inode directly rather -- cgit v1.2.3 From b67a1b9e4bf878aa5d4b6b44cb5a251a2f425f0d Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sun, 30 Oct 2005 15:03:44 -0800 Subject: [PATCH] remove hardcoded SEND_SIG_xxx constants This patch replaces hardcoded SEND_SIG_xxx constants with their symbolic names. No changes in affected .o files. Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index bb62838be496..295ac472faf1 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2713,8 +2713,8 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info, int si if (rc) return rc; - if (info && ((unsigned long)info == 1 || - (unsigned long)info == 2 || SI_FROMKERNEL(info))) + if (info != SEND_SIG_NOINFO && (info == SEND_SIG_PRIV || + info == SEND_SIG_FORCED || SI_FROMKERNEL(info))) return 0; if (!sig) -- cgit v1.2.3 From 621d31219d9a788bda924a0613048053f3f5f211 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sun, 30 Oct 2005 15:03:45 -0800 Subject: [PATCH] cleanup the usage of SEND_SIG_xxx constants This patch simplifies some checks for magic siginfo values. It should not change the behaviour in any way. Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- security/selinux/hooks.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'security/selinux/hooks.c') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 295ac472faf1..45c41490d521 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2713,8 +2713,7 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info, int si if (rc) return rc; - if (info != SEND_SIG_NOINFO && (info == SEND_SIG_PRIV || - info == SEND_SIG_FORCED || SI_FROMKERNEL(info))) + if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info))) return 0; if (!sig) -- cgit v1.2.3