From e53cfe6c7caa79ccdccce53e600dae522acb1c84 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Fri, 26 May 2017 15:07:22 -0700 Subject: [PATCH] apparmor: rework perm mapping to a slightly broader set Signed-off-by: John Johansen --- security/apparmor/file.c | 43 +++++++------------ security/apparmor/include/file.h | 5 ++- security/apparmor/include/perms.h | 69 ++++++++++++++++++++++--------- security/apparmor/lib.c | 59 ++++++++++++++++++++++++++ security/apparmor/lsm.c | 10 ++--- 5 files changed, 133 insertions(+), 53 deletions(-) diff --git a/security/apparmor/file.c b/security/apparmor/file.c index 22be62f0fc73..44549db904b3 100644 --- a/security/apparmor/file.c +++ b/security/apparmor/file.c @@ -21,6 +21,17 @@ struct file_perms nullperms; +static u32 map_mask_to_chr_mask(u32 mask) +{ + u32 m = mask & PERMS_CHRS_MASK; + + if (mask & AA_MAY_GETATTR) + m |= MAY_READ; + if (mask & (AA_MAY_SETATTR | AA_MAY_CHMOD | AA_MAY_CHOWN)) + m |= MAY_WRITE; + + return m; +} /** * audit_file_mask - convert mask to permission string @@ -31,29 +42,7 @@ static void audit_file_mask(struct audit_buffer *ab, u32 mask) { char str[10]; - char *m = str; - - if (mask & AA_EXEC_MMAP) - *m++ = 'm'; - if (mask & (MAY_READ | AA_MAY_META_READ)) - *m++ = 'r'; - if (mask & (MAY_WRITE | AA_MAY_META_WRITE | AA_MAY_CHMOD | - AA_MAY_CHOWN)) - *m++ = 'w'; - else if (mask & MAY_APPEND) - *m++ = 'a'; - if (mask & AA_MAY_CREATE) - *m++ = 'c'; - if (mask & AA_MAY_DELETE) - *m++ = 'd'; - if (mask & AA_MAY_LINK) - *m++ = 'l'; - if (mask & AA_MAY_LOCK) - *m++ = 'k'; - if (mask & MAY_EXEC) - *m++ = 'x'; - *m = '\0'; - + aa_perm_mask_to_str(str, aa_file_perm_chrs, map_mask_to_chr_mask(mask)); audit_log_string(ab, str); } @@ -163,10 +152,10 @@ static u32 map_old_perms(u32 old) { u32 new = old & 0xf; if (old & MAY_READ) - new |= AA_MAY_META_READ; + new |= AA_MAY_GETATTR | AA_MAY_OPEN; if (old & MAY_WRITE) - new |= AA_MAY_META_WRITE | AA_MAY_CREATE | AA_MAY_DELETE | - AA_MAY_CHMOD | AA_MAY_CHOWN; + new |= AA_MAY_SETATTR | AA_MAY_CREATE | AA_MAY_DELETE | + AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_OPEN; if (old & 0x10) new |= AA_MAY_LINK; /* the old mapping lock and link_subset flags where overlaid @@ -214,7 +203,7 @@ static struct file_perms compute_perms(struct aa_dfa *dfa, unsigned int state, perms.quiet = map_old_perms(dfa_other_quiet(dfa, state)); perms.xindex = dfa_other_xindex(dfa, state); } - perms.allow |= AA_MAY_META_READ; + perms.allow |= AA_MAY_GETATTR; /* change_profile wasn't determined by ownership in old mapping */ if (ACCEPT_TABLE(dfa)[state] & 0x80000000) diff --git a/security/apparmor/include/file.h b/security/apparmor/include/file.h index a75e4872053a..fb3642a94e3d 100644 --- a/security/apparmor/include/file.h +++ b/security/apparmor/include/file.h @@ -22,10 +22,11 @@ struct aa_profile; struct path; +#define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND)) #define AA_AUDIT_FILE_MASK (MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\ AA_MAY_CREATE | AA_MAY_DELETE | \ - AA_MAY_META_READ | AA_MAY_META_WRITE | \ + AA_MAY_GETATTR | AA_MAY_SETATTR | \ AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \ AA_EXEC_MMAP | AA_MAY_LINK) @@ -37,7 +38,7 @@ struct path; * ctx struct will expand in the future so we keep the struct. */ struct aa_file_ctx { - u16 allow; + u32 allow; }; /** diff --git a/security/apparmor/include/perms.h b/security/apparmor/include/perms.h index 4a65755a2dc0..35e365e7aa75 100644 --- a/security/apparmor/include/perms.h +++ b/security/apparmor/include/perms.h @@ -16,25 +16,56 @@ #include -/* - * We use MAY_EXEC, MAY_WRITE, MAY_READ, MAY_APPEND and the following flags - * for profile permissions - */ -#define AA_MAY_CREATE 0x0010 -#define AA_MAY_DELETE 0x0020 -#define AA_MAY_META_WRITE 0x0040 -#define AA_MAY_META_READ 0x0080 - -#define AA_MAY_CHMOD 0x0100 -#define AA_MAY_CHOWN 0x0200 -#define AA_MAY_LOCK 0x0400 -#define AA_EXEC_MMAP 0x0800 - -#define AA_MAY_LINK 0x1000 -#define AA_LINK_SUBSET AA_MAY_LOCK /* overlaid */ -#define AA_MAY_ONEXEC 0x40000000 /* exec allows onexec */ -#define AA_MAY_CHANGE_PROFILE 0x80000000 -#define AA_MAY_CHANGEHAT 0x80000000 /* ctrl auditing only */ +#define AA_MAY_EXEC MAY_EXEC +#define AA_MAY_WRITE MAY_WRITE +#define AA_MAY_READ MAY_READ +#define AA_MAY_APPEND MAY_APPEND + +#define AA_MAY_CREATE 0x0010 +#define AA_MAY_DELETE 0x0020 +#define AA_MAY_OPEN 0x0040 +#define AA_MAY_RENAME 0x0080 /* pair */ + +#define AA_MAY_SETATTR 0x0100 /* meta write */ +#define AA_MAY_GETATTR 0x0200 /* meta read */ +#define AA_MAY_SETCRED 0x0400 /* security cred/attr */ +#define AA_MAY_GETCRED 0x0800 + +#define AA_MAY_CHMOD 0x1000 /* pair */ +#define AA_MAY_CHOWN 0x2000 /* pair */ +#define AA_MAY_CHGRP 0x4000 /* pair */ +#define AA_MAY_LOCK 0x8000 /* LINK_SUBSET overlaid */ + +#define AA_EXEC_MMAP 0x00010000 +#define AA_MAY_MPROT 0x00020000 /* extend conditions */ +#define AA_MAY_LINK 0x00040000 /* pair */ +#define AA_MAY_SNAPSHOT 0x00080000 /* pair */ + +#define AA_MAY_DELEGATE +#define AA_CONT_MATCH 0x08000000 + +#define AA_MAY_STACK 0x10000000 +#define AA_MAY_ONEXEC 0x20000000 /* either stack or change_profile */ +#define AA_MAY_CHANGE_PROFILE 0x40000000 +#define AA_MAY_CHANGEHAT 0x80000000 + +#define AA_LINK_SUBSET AA_MAY_LOCK /* overlaid */ + + +#define PERMS_CHRS_MASK (MAY_READ | MAY_WRITE | AA_MAY_CREATE | \ + AA_MAY_DELETE | AA_MAY_LINK | AA_MAY_LOCK | \ + AA_MAY_EXEC | AA_EXEC_MMAP | AA_MAY_APPEND) + +#define PERMS_NAMES_MASK (PERMS_CHRS_MASK | AA_MAY_OPEN | AA_MAY_RENAME | \ + AA_MAY_SETATTR | AA_MAY_GETATTR | AA_MAY_SETCRED | \ + AA_MAY_GETCRED | AA_MAY_CHMOD | AA_MAY_CHOWN | \ + AA_MAY_CHGRP | AA_MAY_MPROT | AA_MAY_SNAPSHOT | \ + AA_MAY_STACK | AA_MAY_ONEXEC | \ + AA_MAY_CHANGE_PROFILE | AA_MAY_CHANGEHAT) + +extern const char aa_file_perm_chrs[]; +extern const char *aa_file_perm_names[]; +void aa_perm_mask_to_str(char *str, const char *chrs, u32 mask); #endif /* __AA_PERM_H */ diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c index 90eb14c9e0cf..90d4631ddafe 100644 --- a/security/apparmor/lib.c +++ b/security/apparmor/lib.c @@ -129,6 +129,65 @@ void aa_info_message(const char *str) printk(KERN_INFO "AppArmor: %s\n", str); } +const char aa_file_perm_chrs[] = "xwracd km l "; +const char *aa_file_perm_names[] = { + "exec", + "write", + "read", + "append", + + "create", + "delete", + "open", + "rename", + + "setattr", + "getattr", + "setcred", + "getcred", + + "chmod", + "chown", + "chgrp", + "lock", + + "mmap", + "mprot", + "link", + "snapshot", + + "unknown", + "unknown", + "unknown", + "unknown", + + "unknown", + "unknown", + "unknown", + "unknown", + + "stack", + "change_onexec", + "change_profile", + "change_hat", +}; + +/** + * aa_perm_mask_to_str - convert a perm mask to its short string + * @str: character buffer to store string in (at least 10 characters) + * @mask: permission mask to convert + */ +void aa_perm_mask_to_str(char *str, const char *chrs, u32 mask) +{ + unsigned int i, perm = 1; + + for (i = 0; i < 32; perm <<= 1, i++) { + if (mask & perm) + *str++ = chrs[i]; + } + *str = '\0'; +} + /** * aa_policy_init - initialize a policy structure * @policy: policy to initialize (NOT NULL) diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 8f3c0f7aca5a..a128f1772135 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -278,7 +278,7 @@ static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry, static int apparmor_path_truncate(const struct path *path) { - return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE); + return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR); } static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry, @@ -323,12 +323,12 @@ static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_d }; error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0, - MAY_READ | AA_MAY_META_READ | MAY_WRITE | - AA_MAY_META_WRITE | AA_MAY_DELETE, + MAY_READ | AA_MAY_GETATTR | MAY_WRITE | + AA_MAY_SETATTR | AA_MAY_DELETE, &cond); if (!error) error = aa_path_perm(OP_RENAME_DEST, profile, &new_path, - 0, MAY_WRITE | AA_MAY_META_WRITE | + 0, MAY_WRITE | AA_MAY_SETATTR | AA_MAY_CREATE, &cond); } @@ -347,7 +347,7 @@ static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid) static int apparmor_inode_getattr(const struct path *path) { - return common_perm_cond(OP_GETATTR, path, AA_MAY_META_READ); + return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR); } static int apparmor_file_open(struct file *file, const struct cred *cred) -- 2.20.1