[PATCH] audit: allow audit_reusename to check kernel path

Currently, audit_reusename check file path only by comparing userspace pointer "uptr", without checking the situation where the file name is different with the same uptr. Add kname into audit_reusename function to check file names from the audit_names list. Signed-off-by: Yiwen Gu <guyiwen(a)huawei.com&gt; --- fs/namei.c | 11 +++++++---- include/linux/audit.h | 11 +++++++---- kernel/auditsc.c | 7 ++++--- 3 files changed, 18 insertions(+), 11 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index db6565c99825..c5623858f3e2 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -128,13 +128,10 @@ struct filename * getname_flags(const char __user *filename, int flags, int *empty) { struct filename *result; + struct filename *result_audit; char *kname; int len; - result = audit_reusename(filename); - if (result) - return result; - result = __getname(); if (unlikely(!result)) return ERR_PTR(-ENOMEM); @@ -197,6 +194,12 @@ getname_flags(const char __user *filename, int flags, int *empty) } } + result_audit = audit_reusename(filename, kname); + if (result_audit) { + putname(result); + return result_audit; + } + result->uptr = filename; result->aname = NULL; audit_getname(result); diff --git a/include/linux/audit.h b/include/linux/audit.h index f9ceae57ca8d..71fb783f14c4 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -266,7 +266,8 @@ extern void __audit_free(struct task_struct *task); extern void __audit_syscall_entry(int major, unsigned long a0, unsigned long a1, unsigned long a2, unsigned long a3); extern void __audit_syscall_exit(int ret_success, long ret_value); -extern struct filename *__audit_reusename(const __user char *uptr); +extern struct filename *__audit_reusename(const __user char *uptr, + const char *kname); extern void __audit_getname(struct filename *name); extern void __audit_inode(struct filename *name, const struct dentry *dentry, @@ -316,10 +317,11 @@ static inline void audit_syscall_exit(void *pt_regs) __audit_syscall_exit(success, return_code); } } -static inline struct filename *audit_reusename(const __user char *name) +static inline struct filename *audit_reusename(const __user char *name, + const char *kname) { if (unlikely(!audit_dummy_context())) - return __audit_reusename(name); + return __audit_reusename(name, kname); return NULL; } static inline void audit_getname(struct filename *name) @@ -539,7 +541,8 @@ static inline struct audit_context *audit_context(void) { return NULL; } -static inline struct filename *audit_reusename(const __user char *name) +static inline struct filename *audit_reusename(const __user char *name, + const char *kname) { return NULL; } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 4effe01ebbe2..62ffc02abb98 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1843,13 +1843,14 @@ 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 + * @kname: kernel pathname string * * Search the audit_names list for the current audit context. If there is an - * existing entry with a matching "uptr" then return the filename + * existing entry with matching "uptr" and "kname" then return the filename * associated with that audit_name. If not, return NULL. */ struct filename * -__audit_reusename(const __user char *uptr) +__audit_reusename(const __user char *uptr, const char *kname) { struct audit_context *context = audit_context(); struct audit_names *n; @@ -1857,7 +1858,7 @@ __audit_reusename(const __user char *uptr) list_for_each_entry(n, &context->names_list, list) { if (!n->name) continue; - if (n->name->uptr == uptr) { + if (n->name->uptr == uptr && !strcmp(kname, n->name->name)) { n->name->refcnt++; return n->name; } -- 2.17.1