AUDIT_PERM support

* two new classes (and their 32bit counterparts) added (READ, WRITE) * new predicate (AUDIT_PERM) to be used with AUDIT_WATCH. True if given kind of access being attempted; f->val is a bitmask, bits are 1 - exec 2 - write 4 - read 8 - attributes modification A few syscalls are dubious: ftruncate, fsync, fdatasync, sync_file_range all need opening for write, so they might be removed from WRITE class. Note that normal file IO (and directory reads) are _not_ included - logging them on those rules would result in logging storms and give no new information since we would catch the corresponding open() anyway. diff --git a/arch/i386/kernel/audit.c b/arch/i386/kernel/audit.c index 5a53c6f..3b97cff 100644 --- a/arch/i386/kernel/audit.c +++ b/arch/i386/kernel/audit.c @@ -8,13 +8,41 @@ #include <asm-generic/audit_dir_write.h> ~0U }; +static unsigned read_class[] = { +#include <asm-generic/audit_read.h> +~0U +}; + +static unsigned write_class[] = { +#include <asm-generic/audit_write.h> +~0U +}; + static unsigned chattr_class[] = { #include <asm-generic/audit_change_attr.h> ~0U }; +int audit_classify_syscall(int abi, unsigned syscall) +{ + switch(syscall) { + case __NR_open: + return 2; + case __NR_openat: + return 3; + case __NR_socketcall: + return 4; + case __NR_execve: + return 5; + default: + return 0; + } +} + static int __init audit_classes_init(void) { + audit_register_class(AUDIT_CLASS_WRITE, write_class); + audit_register_class(AUDIT_CLASS_READ, read_class); audit_register_class(AUDIT_CLASS_DIR_WRITE, dir_class); audit_register_class(AUDIT_CLASS_CHATTR, chattr_class); return 0; diff --git a/arch/ia64/ia32/audit.c b/arch/ia64/ia32/audit.c index ab94f2e..92d7d0c 100644 --- a/arch/ia64/ia32/audit.c +++ b/arch/ia64/ia32/audit.c @@ -9,3 +9,29 @@ unsigned ia32_chattr_class[] = { #include <asm-generic/audit_change_attr.h> ~0U }; + +unsigned ia32_write_class[] = { +#include <asm-generic/audit_write.h> +~0U +}; + +unsigned ia32_read_class[] = { +#include <asm-generic/audit_read.h> +~0U +}; + +int ia32_classify_syscall(unsigned syscall) +{ + switch(syscall) { + case __NR_open: + return 2; + case __NR_openat: + return 3; + case __NR_socketcall: + return 4; + case __NR_execve: + return 5; + default: + return 1; + } +} diff --git a/arch/ia64/kernel/audit.c b/arch/ia64/kernel/audit.c index f251293..21f3338 100644 --- a/arch/ia64/kernel/audit.c +++ b/arch/ia64/kernel/audit.c @@ -8,19 +8,54 @@ #include <asm-generic/audit_dir_write.h> ~0U }; +static unsigned read_class[] = { +#include <asm-generic/audit_read.h> +~0U +}; + +static unsigned write_class[] = { +#include <asm-generic/audit_write.h> +~0U +}; + static unsigned chattr_class[] = { #include <asm-generic/audit_change_attr.h> ~0U }; +int audit_classify_syscall(int abi, unsigned syscall) +{ +#ifdef CONFIG_IA32_EMULATION + extern int ia32_classify_syscall(unsigned); + if (abi == AUDIT_ARCH_I386) + return ia32_classify_syscall(syscall); +#endif + switch(syscall) { + case __NR_open: + return 2; + case __NR_openat: + return 3; + case __NR_execve: + return 5; + default: + return 0; + } +} + static int __init audit_classes_init(void) { -#ifdef CONFIG_IA32_SUPPORT +#ifdef CONFIG_IA32_EMULATION extern __u32 ia32_dir_class[]; + extern __u32 ia32_write_class[]; + extern __u32 ia32_read_class[]; extern __u32 ia32_chattr_class[]; + audit_register_class(AUDIT_CLASS_WRITE_32, ia32_write_class); + audit_register_class(AUDIT_CLASS_READ_32, ia32_read_class); audit_register_class(AUDIT_CLASS_DIR_WRITE_32, ia32_dir_class); audit_register_class(AUDIT_CLASS_CHATTR_32, ia32_chattr_class); #endif + audit_register_class(AUDIT_CLASS_WRITE, write_class); + audit_register_class(AUDIT_CLASS_READ, read_class); audit_register_class(AUDIT_CLASS_DIR_WRITE, dir_class); audit_register_class(AUDIT_CLASS_CHATTR, chattr_class); return 0; diff --git a/arch/x86_64/ia32/audit.c b/arch/x86_64/ia32/audit.c index ab94f2e..92d7d0c 100644 --- a/arch/x86_64/ia32/audit.c +++ b/arch/x86_64/ia32/audit.c @@ -9,3 +9,29 @@ unsigned ia32_chattr_class[] = { #include <asm-generic/audit_change_attr.h> ~0U }; + +unsigned ia32_write_class[] = { +#include <asm-generic/audit_write.h> +~0U +}; + +unsigned ia32_read_class[] = { +#include <asm-generic/audit_read.h> +~0U +}; + +int ia32_classify_syscall(unsigned syscall) +{ + switch(syscall) { + case __NR_open: + return 2; + case __NR_openat: + return 3; + case __NR_socketcall: + return 4; + case __NR_execve: + return 5; + default: + return 1; + } +} diff --git a/arch/x86_64/kernel/audit.c b/arch/x86_64/kernel/audit.c index a067aa4..21f3338 100644 --- a/arch/x86_64/kernel/audit.c +++ b/arch/x86_64/kernel/audit.c @@ -8,19 +8,54 @@ #include <asm-generic/audit_dir_write.h> ~0U }; +static unsigned read_class[] = { +#include <asm-generic/audit_read.h> +~0U +}; + +static unsigned write_class[] = { +#include <asm-generic/audit_write.h> +~0U +}; + static unsigned chattr_class[] = { #include <asm-generic/audit_change_attr.h> ~0U }; +int audit_classify_syscall(int abi, unsigned syscall) +{ +#ifdef CONFIG_IA32_EMULATION + extern int ia32_classify_syscall(unsigned); + if (abi == AUDIT_ARCH_I386) + return ia32_classify_syscall(syscall); +#endif + switch(syscall) { + case __NR_open: + return 2; + case __NR_openat: + return 3; + case __NR_execve: + return 5; + default: + return 0; + } +} + static int __init audit_classes_init(void) { #ifdef CONFIG_IA32_EMULATION extern __u32 ia32_dir_class[]; + extern __u32 ia32_write_class[]; + extern __u32 ia32_read_class[]; extern __u32 ia32_chattr_class[]; + audit_register_class(AUDIT_CLASS_WRITE_32, ia32_write_class); + audit_register_class(AUDIT_CLASS_READ_32, ia32_read_class); audit_register_class(AUDIT_CLASS_DIR_WRITE_32, ia32_dir_class); audit_register_class(AUDIT_CLASS_CHATTR_32, ia32_chattr_class); #endif + audit_register_class(AUDIT_CLASS_WRITE, write_class); + audit_register_class(AUDIT_CLASS_READ, read_class); audit_register_class(AUDIT_CLASS_DIR_WRITE, dir_class); audit_register_class(AUDIT_CLASS_CHATTR, chattr_class); return 0; diff --git a/include/asm-generic/audit_read.h b/include/asm-generic/audit_read.h new file mode 100644 index 0000000..0e87464 --- /dev/null +++ b/include/asm-generic/audit_read.h @@ -0,0 +1,8 @@ +__NR_readlink, +__NR_quotactl, +__NR_listxattr, +__NR_llistxattr, +__NR_flistxattr, +__NR_getxattr, +__NR_lgetxattr, +__NR_fgetxattr, diff --git a/include/asm-generic/audit_write.h b/include/asm-generic/audit_write.h new file mode 100644 index 0000000..affc7a1 --- /dev/null +++ b/include/asm-generic/audit_write.h @@ -0,0 +1,18 @@ +#include <asm-generic/audit_dir_write.h> +__NR_acct, +__NR_swapon, +__NR_quotactl, +__NR_truncate, +#ifdef __NR_truncate64 +__NR_truncate64, +__NR_ftruncate64, /* ? */ +#endif +__NR_fsync, /* ? */ +__NR_fdatasync, /* ? */ +__NR_ftruncate, /* ? */ +#ifdef __NR_sync_file_range +__NR_sync_file_range, /* ? */ +#endif +#ifdef __NR_bind +__NR_bind, /* bind can affect fs object only in one way... */ +#endif diff --git a/include/linux/audit.h b/include/linux/audit.h index 64f9f9e..e947e67 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -132,6 +132,10 @@ #define AUDIT_CLASS_DIR_WRITE 0 #define AUDIT_CLASS_DIR_WRITE_32 1 #define AUDIT_CLASS_CHATTR 2 #define AUDIT_CLASS_CHATTR_32 3 +#define AUDIT_CLASS_READ 4 +#define AUDIT_CLASS_READ_32 5 +#define AUDIT_CLASS_WRITE 6 +#define AUDIT_CLASS_WRITE_32 7 /* This bitmask is used to validate user input. It represents all bits that * are currently used in an audit field constant understood by the kernel. @@ -177,6 +181,7 @@ #define AUDIT_INODE 102 #define AUDIT_EXIT 103 #define AUDIT_SUCCESS 104 /* exit >= 0; value ignored */ #define AUDIT_WATCH 105 +#define AUDIT_PERM 106 #define AUDIT_ARG0 200 #define AUDIT_ARG1 (AUDIT_ARG0+1) @@ -314,6 +319,7 @@ #define AUDITSC_SUCCESS 1 #define AUDITSC_FAILURE 2 #define AUDITSC_RESULT(x) ( ((long)(x))<0?AUDITSC_FAILURE:AUDITSC_SUCCESS ) extern int __init audit_register_class(int class, unsigned *list); +extern int audit_classify_syscall(int abi, unsigned syscall); #ifdef CONFIG_AUDITSYSCALL /* These are defined in auditsc.c */ /* Public API */ diff --git a/kernel/audit.h b/kernel/audit.h index 6aa33b8..a337023 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -104,6 +104,7 @@ static inline int audit_hash_ino(u32 ino return (ino & (AUDIT_INODE_BUCKETS-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_compare_dname_path(const char *dname, const char *path, int *dirlen); diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 6a9a5c5..e1f7fce 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -302,6 +302,15 @@ int __init audit_register_class(int clas return 0; } +int audit_match_class(int class, unsigned syscall) +{ + if (unlikely(syscall >= AUDIT_BITMASK_SIZE * sizeof(__u32))) + return 0; + if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) + return 0; + return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); +} + /* Common user-space to kernel rule translation. */ static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) { @@ -413,6 +422,10 @@ static struct audit_entry *audit_rule_to case AUDIT_ARG2: case AUDIT_ARG3: break; + case AUDIT_PERM: + if (f->val & ~15) + goto exit_free; + break; case AUDIT_INODE: err = audit_to_inode(&entry->rule, f); if (err) @@ -567,6 +580,10 @@ static struct audit_entry *audit_data_to entry->rule.buflen += f->val; entry->rule.filterkey = str; break; + case AUDIT_PERM: + if (f->val & ~15) + goto exit_free; + break; default: goto exit_free; } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index efc1b74..7a83d80 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -209,6 +209,40 @@ #if AUDIT_DEBUG #endif }; +#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE]) +static int audit_match_perm(struct audit_context *ctx, int mask) +{ + unsigned n = ctx->major; + switch (audit_classify_syscall(ctx->arch, n)) { + case 0: /* native */ + if ((mask & 2) && audit_match_class(AUDIT_CLASS_WRITE, n)) + return 1; + if ((mask & 4) && audit_match_class(AUDIT_CLASS_READ, n)) + return 1; + if ((mask & 8) && audit_match_class(AUDIT_CLASS_CHATTR, n)) + return 1; + return 0; + case 1: /* 32bit on biarch */ + if ((mask & 2) && audit_match_class(AUDIT_CLASS_WRITE_32, n)) + return 1; + if ((mask & 4) && audit_match_class(AUDIT_CLASS_READ_32, n)) + return 1; + if ((mask & 8) && audit_match_class(AUDIT_CLASS_CHATTR_32, n)) + return 1; + return 0; + case 2: /* open */ + return mask & ACC_MODE(ctx->argv[1]); + case 3: /* openat */ + return mask & ACC_MODE(ctx->argv[2]); + case 4: /* socketcall */ + return ((mask & 2) && ctx->argv[0] == SYS_BIND); + case 5: /* execve */ + return mask & 1; + default: + return 0; + } +} + /* Determine if any context name data matches a rule's watch data */ /* Compare a task_struct with an audit_rule. Return 1 on match, 0 * otherwise. */ @@ -397,6 +431,9 @@ static int audit_filter_rules(struct tas /* ignore this field for filtering */ result = 1; break; + case AUDIT_PERM: + result = audit_match_perm(ctx, f->val); + break; } if (!result)