Re: [PATCH ghak96] audit: set cwd in audit context for file-related LSM audit records

Set a current working directory in an audit context for the following record types in dump_common_audit_data(): LSM_AUDIT_DATA_PATH, LSM_AUDIT_DATA_FILE, LSM_AUDIT_DATA_IOCTL_OP, LSM_AUDIT_DATA_DENTRY, LSM_AUDIT_DATA_INODE so a separate CWD record is emitted later. Link: https://github.com/linux-audit/audit-kernel/issues/96

Signed-off-by: Vladis Dronov <vdronov(a)redhat.com&gt; --- out-of-commit-message-note: Hello, Honestly, I'm not sure about "if (!context->in_syscall)" check in __audit_getcwd(). It was copied from __audit_getname() and I do not quite understand why it is there and if __audit_getcwd() needs it. If you have an idea on this, could you please, tell? include/linux/audit.h | 9 ++++++++- kernel/auditsc.c | 17 +++++++++++++++++ security/lsm_audit.c | 5 +++++ 3 files changed, 30 insertions(+), 1 deletion(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index f9ceae57ca8d..b4306abc5891 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -268,7 +268,7 @@ extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1, extern void __audit_syscall_exit(int ret_success, long ret_value); extern struct filename *__audit_reusename(const __user char *uptr); extern void __audit_getname(struct filename *name); - +extern void __audit_getcwd(void); extern void __audit_inode(struct filename *name, const struct dentry *dentry, unsigned int flags); extern void __audit_file(const struct file *); @@ -327,6 +327,11 @@ static inline void audit_getname(struct filename *name) if (unlikely(!audit_dummy_context())) __audit_getname(name); } +static inline void audit_getcwd(void) +{ + if (unlikely(!audit_dummy_context())) + __audit_getcwd(); +} static inline void audit_inode(struct filename *name, const struct dentry *dentry, unsigned int aflags) { @@ -545,6 +550,8 @@ static inline struct filename *audit_reusename(const __user char *name) } static inline void audit_getname(struct filename *name) { } +static inline void audit_getcwd(void) +{ } static inline void __audit_inode(struct filename *name, const struct dentry *dentry, unsigned int flags) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 814406a35db1..16316032ef9f 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1890,6 +1890,23 @@ void __audit_getname(struct filename *name) get_fs_pwd(current->fs, &context->pwd); } +/** + * __audit_getcwd - set a current working directory + * + * Set a current working directory of an audited process for this context. + * Called from security/lsm_audit.c:dump_common_audit_data(). + */ +void __audit_getcwd(void) +{ + struct audit_context *context = audit_context(); + + if (!context->in_syscall) + return; + + if (!context->pwd.dentry) + get_fs_pwd(current->fs, &context->pwd); +} + static inline int audit_copy_fcaps(struct audit_names *name, const struct dentry *dentry) { diff --git a/security/lsm_audit.c b/security/lsm_audit.c index 2d2bf49016f4..7c555621c2bd 100644 --- a/security/lsm_audit.c +++ b/security/lsm_audit.c @@ -241,6 +241,7 @@ static void dump_common_audit_data(struct audit_buffer *ab, audit_log_untrustedstring(ab, inode->i_sb->s_id); audit_log_format(ab, " ino=%lu", inode->i_ino); } + audit_getcwd(); break; } case LSM_AUDIT_DATA_FILE: { @@ -254,6 +255,7 @@ static void dump_common_audit_data(struct audit_buffer *ab, audit_log_untrustedstring(ab, inode->i_sb->s_id); audit_log_format(ab, " ino=%lu", inode->i_ino); } + audit_getcwd(); break; } case LSM_AUDIT_DATA_IOCTL_OP: { @@ -269,6 +271,7 @@ static void dump_common_audit_data(struct audit_buffer *ab, } audit_log_format(ab, " ioctlcmd=0x%hx", a->u.op->cmd); + audit_getcwd(); break; } case LSM_AUDIT_DATA_DENTRY: { @@ -283,6 +286,7 @@ static void dump_common_audit_data(struct audit_buffer *ab, audit_log_untrustedstring(ab, inode->i_sb->s_id); audit_log_format(ab, " ino=%lu", inode->i_ino); } + audit_getcwd(); break; } case LSM_AUDIT_DATA_INODE: { @@ -300,6 +304,7 @@ static void dump_common_audit_data(struct audit_buffer *ab, audit_log_format(ab, " dev="); audit_log_untrustedstring(ab, inode->i_sb->s_id); audit_log_format(ab, " ino=%lu", inode->i_ino); + audit_getcwd(); break; } case LSM_AUDIT_DATA_TASK: {