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| author | Jeff Layton <jlayton@redhat.com> | 2012-10-10 15:25:28 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-12 20:15:08 -0400 |
| commit | 7ac86265dc8f665cc49d6e60a125e608cd2fca14 (patch) | |
| tree | 9e7941e2d8dfb2106c5fb28504531dafc72e14e6 | |
| parent | 91a27b2a756784714e924e5e854b919273082d26 (diff) | |
| download | linux-7ac86265dc8f665cc49d6e60a125e608cd2fca14.tar.gz linux-7ac86265dc8f665cc49d6e60a125e608cd2fca14.tar.bz2 linux-7ac86265dc8f665cc49d6e60a125e608cd2fca14.zip | |
audit: allow audit code to satisfy getname requests from its names_list
Currently, if we call getname() on a userland string more than once,
we'll get multiple copies of the string and multiple audit_names
records.
Add a function that will allow the audit_names code to satisfy getname
requests using info from the audit_names list, avoiding a new allocation
and audit_names records.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/namei.c | 4 | ||||
| -rw-r--r-- | include/linux/audit.h | 11 | ||||
| -rw-r--r-- | kernel/auditsc.c | 23 |
3 files changed, 38 insertions, 0 deletions
diff --git a/fs/namei.c b/fs/namei.c index ec638d27642f..5dbc3f836934 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -130,6 +130,10 @@ getname_flags(const char __user *filename, int flags, int *empty) char *kname; int len; + result = audit_reusename(filename); + if (result) + return result; + /* FIXME: create dedicated slabcache? */ result = kzalloc(sizeof(*result), GFP_KERNEL); if (unlikely(!result)) diff --git a/include/linux/audit.h b/include/linux/audit.h index 94d29164803f..d5d7952ab7d8 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -471,6 +471,7 @@ extern void __audit_syscall_entry(int arch, 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 void __audit_getname(struct filename *name); extern void audit_putname(struct filename *name); extern void __audit_inode(const char *name, const struct dentry *dentry, @@ -507,6 +508,12 @@ 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) +{ + if (unlikely(!audit_dummy_context())) + return __audit_reusename(name); + return NULL; +} static inline void audit_getname(struct filename *name) { if (unlikely(!audit_dummy_context())) @@ -665,6 +672,10 @@ static inline int audit_dummy_context(void) { return 1; } +static inline struct filename *audit_reusename(const __user char *name) +{ + return NULL; +} static inline void audit_getname(struct filename *name) { } static inline void audit_putname(struct filename *name) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index d4d82319eed5..521163a5d65f 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2021,6 +2021,29 @@ 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 * |