diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-13 10:04:42 +0900 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-13 10:04:42 +0900 |
commit | 8418263e3547ed3816475e4c55a77004f0426ee6 (patch) | |
tree | 97c548b16e6753e1911870d824a07b7e726b6229 /kernel | |
parent | ccff9b1db693062b0a9c9070f4304deb47ef215c (diff) | |
parent | f81700bd831efcd12eb7f0e66b24b16c2ad00a32 (diff) | |
download | op-kernel-dev-8418263e3547ed3816475e4c55a77004f0426ee6.zip op-kernel-dev-8418263e3547ed3816475e4c55a77004f0426ee6.tar.gz |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull third pile of VFS updates from Al Viro:
"Stuff from Jeff Layton, mostly. Sanitizing interplay between audit
and namei, removing a lot of insanity from audit_inode() mess and
getting things ready for his ESTALE patchset."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
procfs: don't need a PATH_MAX allocation to hold a string representation of an int
vfs: embed struct filename inside of names_cache allocation if possible
audit: make audit_inode take struct filename
vfs: make path_openat take a struct filename pointer
vfs: turn do_path_lookup into wrapper around struct filename variant
audit: allow audit code to satisfy getname requests from its names_list
vfs: define struct filename and have getname() return it
vfs: unexport getname and putname symbols
acct: constify the name arg to acct_on
vfs: allocate page instead of names_cache buffer in mount_block_root
audit: overhaul __audit_inode_child to accomodate retrying
audit: optimize audit_compare_dname_path
audit: make audit_compare_dname_path use parent_len helper
audit: remove dirlen argument to audit_compare_dname_path
audit: set the name_len in audit_inode for parent lookups
audit: add a new "type" field to audit_names struct
audit: reverse arguments to audit_inode_child
audit: no need to walk list in audit_inode if name is NULL
audit: pass in dentry to audit_copy_inode wherever possible
audit: remove unnecessary NULL ptr checks from do_path_lookup
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/acct.c | 6 | ||||
-rw-r--r-- | kernel/audit.h | 7 | ||||
-rw-r--r-- | kernel/audit_watch.c | 3 | ||||
-rw-r--r-- | kernel/auditfilter.c | 65 | ||||
-rw-r--r-- | kernel/auditsc.c | 217 |
5 files changed, 199 insertions, 99 deletions
diff --git a/kernel/acct.c b/kernel/acct.c index 6cd7529..051e071 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -193,7 +193,7 @@ static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file, } } -static int acct_on(char *name) +static int acct_on(struct filename *pathname) { struct file *file; struct vfsmount *mnt; @@ -201,7 +201,7 @@ static int acct_on(char *name) struct bsd_acct_struct *acct = NULL; /* Difference from BSD - they don't do O_APPEND */ - file = filp_open(name, O_WRONLY|O_APPEND|O_LARGEFILE, 0); + file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0); if (IS_ERR(file)) return PTR_ERR(file); @@ -260,7 +260,7 @@ SYSCALL_DEFINE1(acct, const char __user *, name) return -EPERM; if (name) { - char *tmp = getname(name); + struct filename *tmp = getname(name); if (IS_ERR(tmp)) return (PTR_ERR(tmp)); error = acct_on(tmp); diff --git a/kernel/audit.h b/kernel/audit.h index 9eb3d79..d51cba8 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -74,12 +74,15 @@ static inline int audit_hash_ino(u32 ino) return (ino & (AUDIT_INODE_BUCKETS-1)); } +/* Indicates that audit should log the full pathname. */ +#define AUDIT_NAME_FULL -1 + extern int audit_match_class(int class, unsigned syscall); extern int audit_comparator(const u32 left, const u32 op, const u32 right); extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right); extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right); -extern int audit_compare_dname_path(const char *dname, const char *path, - int *dirlen); +extern int parent_len(const char *path); +extern int audit_compare_dname_path(const char *dname, const char *path, int plen); extern struct sk_buff * audit_make_reply(int pid, int seq, int type, int done, int multi, const void *payload, int size); diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c index 1c22ec3..9a9ae6e 100644 --- a/kernel/audit_watch.c +++ b/kernel/audit_watch.c @@ -265,7 +265,8 @@ static void audit_update_watch(struct audit_parent *parent, /* Run all of the watches on this parent looking for the one that * matches the given dname */ list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) { - if (audit_compare_dname_path(dname, owatch->path, NULL)) + if (audit_compare_dname_path(dname, owatch->path, + AUDIT_NAME_FULL)) continue; /* If the update involves invalidating rules, do the inode-based diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index c4bcdba..7f19f23 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -1298,41 +1298,60 @@ int audit_gid_comparator(kgid_t left, u32 op, kgid_t right) } } -/* Compare given dentry name with last component in given path, - * return of 0 indicates a match. */ -int audit_compare_dname_path(const char *dname, const char *path, - int *dirlen) +/** + * parent_len - find the length of the parent portion of a pathname + * @path: pathname of which to determine length + */ +int parent_len(const char *path) { - int dlen, plen; + int plen; const char *p; - if (!dname || !path) - return 1; - - dlen = strlen(dname); plen = strlen(path); - if (plen < dlen) - return 1; + + if (plen == 0) + return plen; /* disregard trailing slashes */ p = path + plen - 1; while ((*p == '/') && (p > path)) p--; - /* find last path component */ - p = p - dlen + 1; - if (p < path) + /* walk backward until we find the next slash or hit beginning */ + while ((*p != '/') && (p > path)) + p--; + + /* did we find a slash? Then increment to include it in path */ + if (*p == '/') + p++; + + return p - path; +} + +/** + * audit_compare_dname_path - compare given dentry name with last component in + * given path. Return of 0 indicates a match. + * @dname: dentry name that we're comparing + * @path: full pathname that we're comparing + * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL + * here indicates that we must compute this value. + */ +int audit_compare_dname_path(const char *dname, const char *path, int parentlen) +{ + int dlen, pathlen; + const char *p; + + dlen = strlen(dname); + pathlen = strlen(path); + if (pathlen < dlen) return 1; - else if (p > path) { - if (*--p != '/') - return 1; - else - p++; - } - /* return length of path's directory component */ - if (dirlen) - *dirlen = p - path; + parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen; + if (pathlen - parentlen != dlen) + return 1; + + p = path + parentlen; + return strncmp(p, dname, dlen); } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index f4a7756..2f186ed 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -81,9 +81,6 @@ * a name dynamically and also add those to the list anchored by names_list. */ #define AUDIT_NAMES 5 -/* Indicates that audit should log the full pathname. */ -#define AUDIT_NAME_FULL -1 - /* no execve audit message should be longer than this (userspace limits) */ #define MAX_EXECVE_AUDIT_LEN 7500 @@ -106,27 +103,29 @@ struct audit_cap_data { * we don't let putname() free it (instead we free all of the saved * pointers at syscall exit time). * - * Further, in fs/namei.c:path_lookup() we store the inode and device. */ + * Further, in fs/namei.c:path_lookup() we store the inode and device. + */ struct audit_names { - struct list_head list; /* audit_context->names_list */ - const char *name; - unsigned long ino; - dev_t dev; - umode_t mode; - kuid_t uid; - kgid_t gid; - dev_t rdev; - u32 osid; - struct audit_cap_data fcap; - unsigned int fcap_ver; - int name_len; /* number of name's characters to log */ - bool name_put; /* call __putname() for this name */ + struct list_head list; /* audit_context->names_list */ + struct filename *name; + unsigned long ino; + dev_t dev; + umode_t mode; + kuid_t uid; + kgid_t gid; + dev_t rdev; + u32 osid; + struct audit_cap_data fcap; + unsigned int fcap_ver; + int name_len; /* number of name's characters to log */ + unsigned char type; /* record type */ + bool name_put; /* call __putname() for this name */ /* * This was an allocated audit_names and not from the array of * names allocated in the task audit context. Thus this name * should be freed on syscall exit */ - bool should_free; + bool should_free; }; struct audit_aux_data { @@ -998,7 +997,7 @@ static inline void audit_free_names(struct audit_context *context) context->ino_count); list_for_each_entry(n, &context->names_list, list) { printk(KERN_ERR "names[%d] = %p = %s\n", i, - n->name, n->name ?: "(null)"); + n->name, n->name->name ?: "(null)"); } dump_stack(); return; @@ -1555,7 +1554,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, case AUDIT_NAME_FULL: /* log the full path */ audit_log_format(ab, " name="); - audit_log_untrustedstring(ab, n->name); + audit_log_untrustedstring(ab, n->name->name); break; case 0: /* name was specified as a relative path and the @@ -1565,7 +1564,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, default: /* log the name's directory component */ audit_log_format(ab, " name="); - audit_log_n_untrustedstring(ab, n->name, + audit_log_n_untrustedstring(ab, n->name->name, n->name_len); } } else @@ -1995,7 +1994,8 @@ retry: #endif } -static struct audit_names *audit_alloc_name(struct audit_context *context) +static struct audit_names *audit_alloc_name(struct audit_context *context, + unsigned char type) { struct audit_names *aname; @@ -2010,6 +2010,7 @@ static struct audit_names *audit_alloc_name(struct audit_context *context) } aname->ino = (unsigned long)-1; + aname->type = type; list_add_tail(&aname->list, &context->names_list); context->name_count++; @@ -2020,13 +2021,36 @@ static struct audit_names *audit_alloc_name(struct audit_context *context) } /** + * audit_reusename - fill out filename with info from existing entry + * @uptr: userland ptr to pathname + * + * Search the audit_names list for the current audit context. If there is an + * existing entry with a matching "uptr" then return the filename + * associated with that audit_name. If not, return NULL. + */ +struct filename * +__audit_reusename(const __user char *uptr) +{ + struct audit_context *context = current->audit_context; + struct audit_names *n; + + list_for_each_entry(n, &context->names_list, list) { + if (!n->name) + continue; + if (n->name->uptr == uptr) + return n->name; + } + return NULL; +} + +/** * audit_getname - add a name to the list * @name: name to add * * Add a name to the list of audit names for this context. * Called from fs/namei.c:getname(). */ -void __audit_getname(const char *name) +void __audit_getname(struct filename *name) { struct audit_context *context = current->audit_context; struct audit_names *n; @@ -2040,13 +2064,19 @@ void __audit_getname(const char *name) return; } - n = audit_alloc_name(context); +#if AUDIT_DEBUG + /* The filename _must_ have a populated ->name */ + BUG_ON(!name->name); +#endif + + n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN); if (!n) return; n->name = name; n->name_len = AUDIT_NAME_FULL; n->name_put = true; + name->aname = n; if (!context->pwd.dentry) get_fs_pwd(current->fs, &context->pwd); @@ -2059,7 +2089,7 @@ void __audit_getname(const char *name) * then we delay the putname until syscall exit. * Called from include/linux/fs.h:putname(). */ -void audit_putname(const char *name) +void audit_putname(struct filename *name) { struct audit_context *context = current->audit_context; @@ -2074,7 +2104,7 @@ void audit_putname(const char *name) list_for_each_entry(n, &context->names_list, list) printk(KERN_ERR "name[%d] = %p = %s\n", i, - n->name, n->name ?: "(null)"); + n->name, n->name->name ?: "(null)"); } #endif __putname(name); @@ -2088,8 +2118,8 @@ void audit_putname(const char *name) " put_count=%d\n", __FILE__, __LINE__, context->serial, context->major, - context->in_syscall, name, context->name_count, - context->put_count); + context->in_syscall, name->name, + context->name_count, context->put_count); dump_stack(); } } @@ -2132,13 +2162,13 @@ static void audit_copy_inode(struct audit_names *name, const struct dentry *dent } /** - * audit_inode - store the inode and device from a lookup + * __audit_inode - store the inode and device from a lookup * @name: name being audited * @dentry: dentry being audited - * - * Called from fs/namei.c:path_lookup(). + * @parent: does this dentry represent the parent? */ -void __audit_inode(const char *name, const struct dentry *dentry) +void __audit_inode(struct filename *name, const struct dentry *dentry, + unsigned int parent) { struct audit_context *context = current->audit_context; const struct inode *inode = dentry->d_inode; @@ -2147,24 +2177,69 @@ void __audit_inode(const char *name, const struct dentry *dentry) if (!context->in_syscall) return; + if (!name) + goto out_alloc; + +#if AUDIT_DEBUG + /* The struct filename _must_ have a populated ->name */ + BUG_ON(!name->name); +#endif + /* + * If we have a pointer to an audit_names entry already, then we can + * just use it directly if the type is correct. + */ + n = name->aname; + if (n) { + if (parent) { + if (n->type == AUDIT_TYPE_PARENT || + n->type == AUDIT_TYPE_UNKNOWN) + goto out; + } else { + if (n->type != AUDIT_TYPE_PARENT) + goto out; + } + } + list_for_each_entry_reverse(n, &context->names_list, list) { - if (n->name && (n->name == name)) - goto out; + /* does the name pointer match? */ + if (!n->name || n->name->name != name->name) + continue; + + /* match the correct record type */ + if (parent) { + if (n->type == AUDIT_TYPE_PARENT || + n->type == AUDIT_TYPE_UNKNOWN) + goto out; + } else { + if (n->type != AUDIT_TYPE_PARENT) + goto out; + } } - /* unable to find the name from a previous getname() */ - n = audit_alloc_name(context); +out_alloc: + /* unable to find the name from a previous getname(). Allocate a new + * anonymous entry. + */ + n = audit_alloc_name(context, AUDIT_TYPE_NORMAL); if (!n) return; out: + if (parent) { + n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL; + n->type = AUDIT_TYPE_PARENT; + } else { + n->name_len = AUDIT_NAME_FULL; + n->type = AUDIT_TYPE_NORMAL; + } handle_path(dentry); audit_copy_inode(n, dentry, inode); } /** - * audit_inode_child - collect inode info for created/removed objects - * @dentry: dentry being audited + * __audit_inode_child - collect inode info for created/removed objects * @parent: inode of dentry parent + * @dentry: dentry being audited + * @type: AUDIT_TYPE_* value that we're looking for * * For syscalls that create or remove filesystem objects, audit_inode * can only collect information for the filesystem object's parent. @@ -2174,15 +2249,14 @@ out: * must be hooked prior, in order to capture the target inode during * unsuccessful attempts. */ -void __audit_inode_child(const struct dentry *dentry, - const struct inode *parent) +void __audit_inode_child(const struct inode *parent, + const struct dentry *dentry, + const unsigned char type) { struct audit_context *context = current->audit_context; - const char *found_parent = NULL, *found_child = NULL; const struct inode *inode = dentry->d_inode; const char *dname = dentry->d_name.name; - struct audit_names *n; - int dirlen = 0; + struct audit_names *n, *found_parent = NULL, *found_child = NULL; if (!context->in_syscall) return; @@ -2190,62 +2264,65 @@ void __audit_inode_child(const struct dentry *dentry, if (inode) handle_one(inode); - /* parent is more likely, look for it first */ + /* look for a parent entry first */ list_for_each_entry(n, &context->names_list, list) { - if (!n->name) + if (!n->name || n->type != AUDIT_TYPE_PARENT) continue; if (n->ino == parent->i_ino && - !audit_compare_dname_path(dname, n->name, &dirlen)) { - n->name_len = dirlen; /* update parent data in place */ - found_parent = n->name; - goto add_names; + !audit_compare_dname_path(dname, n->name->name, n->name_len)) { + found_parent = n; + break; } } - /* no matching parent, look for matching child */ + /* is there a matching child entry? */ list_for_each_entry(n, &context->names_list, list) { - if (!n->name) + /* can only match entries that have a name */ + if (!n->name || n->type != type) continue; - /* strcmp() is the more likely scenario */ - if (!strcmp(dname, n->name) || - !audit_compare_dname_path(dname, n->name, &dirlen)) { - if (inode) - audit_copy_inode(n, NULL, inode); - else - n->ino = (unsigned long)-1; - found_child = n->name; - goto add_names; + /* if we found a parent, make sure this one is a child of it */ + if (found_parent && (n->name != found_parent->name)) + continue; + + if (!strcmp(dname, n->name->name) || + !audit_compare_dname_path(dname, n->name->name, + found_parent ? + found_parent->name_len : + AUDIT_NAME_FULL)) { + found_child = n; + break; } } -add_names: if (!found_parent) { - n = audit_alloc_name(context); + /* create a new, "anonymous" parent record */ + n = audit_alloc_name(context, AUDIT_TYPE_PARENT); if (!n) return; audit_copy_inode(n, NULL, parent); } if (!found_child) { - n = audit_alloc_name(context); - if (!n) + found_child = audit_alloc_name(context, type); + if (!found_child) return; /* Re-use the name belonging to the slot for a matching parent * directory. All names for this context are relinquished in * audit_free_names() */ if (found_parent) { - n->name = found_parent; - n->name_len = AUDIT_NAME_FULL; + found_child->name = found_parent->name; + found_child->name_len = AUDIT_NAME_FULL; /* don't call __putname() */ - n->name_put = false; + found_child->name_put = false; } - - if (inode) - audit_copy_inode(n, NULL, inode); } + if (inode) + audit_copy_inode(found_child, dentry, inode); + else + found_child->ino = (unsigned long)-1; } EXPORT_SYMBOL_GPL(__audit_inode_child); |