audit: Report suspicious O_CREAT usage
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Message ID 201909251348.A1542A52@keescook
State New
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  • audit: Report suspicious O_CREAT usage
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Commit Message

Kees Cook Sept. 25, 2019, 9:02 p.m. UTC
This renames the very specific audit_log_link_denied() to
audit_log_path_denied() and adds the AUDIT_* type as an argument. This
allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
report the fifo/regular file creation restrictions that were introduced
in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and
regular files"). Without this change, discovering that the restriction
is enabled can be very challenging:
https://lore.kernel.org/lkml/CA+jJMxvkqjXHy3DnV5MVhFTL2RUhg0WQ-XVFW3ngDQOdkFq0PA@mail.gmail.com

Reported-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
This is not a complete fix because reporting was broken in commit
15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
audit_dummy_context")
which specifically goes against the intention of these records: they
should _always_ be reported. If auditing isn't enabled, they should be
ratelimited.

Instead of using audit, should this just go back to using
pr_ratelimited()?
---
 fs/namei.c                 |  7 +++++--
 include/linux/audit.h      |  5 +++--
 include/uapi/linux/audit.h |  1 +
 kernel/audit.c             | 11 ++++++-----
 4 files changed, 15 insertions(+), 9 deletions(-)

Comments

Kees Cook Sept. 25, 2019, 11:14 p.m. UTC | #1
On Wed, Sep 25, 2019 at 02:02:33PM -0700, Kees Cook wrote:
> This renames the very specific audit_log_link_denied() to
> audit_log_path_denied() and adds the AUDIT_* type as an argument. This
> allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
> report the fifo/regular file creation restrictions that were introduced
> in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and
> regular files"). Without this change, discovering that the restriction
> is enabled can be very challenging:
> https://lore.kernel.org/lkml/CA+jJMxvkqjXHy3DnV5MVhFTL2RUhg0WQ-XVFW3ngDQOdkFq0PA@mail.gmail.com
> 
> Reported-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> This is not a complete fix because reporting was broken in commit
> 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> audit_dummy_context")
> which specifically goes against the intention of these records: they
> should _always_ be reported. If auditing isn't enabled, they should be
> ratelimited.
> 
> Instead of using audit, should this just go back to using
> pr_ratelimited()?
> ---
>  fs/namei.c                 |  7 +++++--
>  include/linux/audit.h      |  5 +++--
>  include/uapi/linux/audit.h |  1 +
>  kernel/audit.c             | 11 ++++++-----
>  4 files changed, 15 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/namei.c b/fs/namei.c
> index 671c3c1a3425..0e60f81e1d5a 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -925,7 +925,7 @@ static inline int may_follow_link(struct nameidata *nd)
>  		return -ECHILD;
>  
>  	audit_inode(nd->name, nd->stack[0].link.dentry, 0);
> -	audit_log_link_denied("follow_link");
> +	audit_log_path_denied(AUDIT_ANOM_LINK, "follow_link");
>  	return -EACCES;
>  }
>  
> @@ -993,7 +993,7 @@ static int may_linkat(struct path *link)
>  	if (safe_hardlink_source(inode) || inode_owner_or_capable(inode))
>  		return 0;
>  
> -	audit_log_link_denied("linkat");
> +	audit_log_path_denied(AUDIT_ANOM_LINK, "linkat");
>  	return -EPERM;
>  }
>  
> @@ -1031,6 +1031,9 @@ static int may_create_in_sticky(struct dentry * const dir,
>  	    (dir->d_inode->i_mode & 0020 &&
>  	     ((sysctl_protected_fifos >= 2 && S_ISFIFO(inode->i_mode)) ||
>  	      (sysctl_protected_regular >= 2 && S_ISREG(inode->i_mode))))) {
> +		audit_log_path_denied(AUDIT_ANOM_CREAT,
> +				      S_ISFIFO(inode->i_mode) ? "fifo"
> +							      : "regular");
>  		return -EACCES;
>  	}
>  	return 0;
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index aee3dc9eb378..b3715e2ee1c5 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -156,7 +156,8 @@ extern void		    audit_log_d_path(struct audit_buffer *ab,
>  					     const struct path *path);
>  extern void		    audit_log_key(struct audit_buffer *ab,
>  					  char *key);
> -extern void		    audit_log_link_denied(const char *operation);
> +extern void		    audit_log_path_denied(int type,
> +						  const char *operation);
>  extern void		    audit_log_lost(const char *message);
>  
>  extern int audit_log_task_context(struct audit_buffer *ab);
> @@ -217,7 +218,7 @@ static inline void audit_log_d_path(struct audit_buffer *ab,
>  { }
>  static inline void audit_log_key(struct audit_buffer *ab, char *key)
>  { }
> -static inline void audit_log_link_denied(const char *string)
> +static inline void audit_log_path_denied(int type, const char *string);

Oops, typo above (should be no trailing ";"). Thanks 0day-bot! I didn't
build without CONFIG_AUDIT. :)

-Kees

>  { }
>  static inline int audit_log_task_context(struct audit_buffer *ab)
>  {
> diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> index c89c6495983d..3ad935527177 100644
> --- a/include/uapi/linux/audit.h
> +++ b/include/uapi/linux/audit.h
> @@ -143,6 +143,7 @@
>  #define AUDIT_ANOM_PROMISCUOUS      1700 /* Device changed promiscuous mode */
>  #define AUDIT_ANOM_ABEND            1701 /* Process ended abnormally */
>  #define AUDIT_ANOM_LINK		    1702 /* Suspicious use of file links */
> +#define AUDIT_ANOM_CREAT	    1703 /* Suspicious file creation */
>  #define AUDIT_INTEGRITY_DATA	    1800 /* Data integrity verification */
>  #define AUDIT_INTEGRITY_METADATA    1801 /* Metadata integrity verification */
>  #define AUDIT_INTEGRITY_STATUS	    1802 /* Integrity enable status */
> diff --git a/kernel/audit.c b/kernel/audit.c
> index da8dc0db5bd3..ed7402ac81b6 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2155,18 +2155,19 @@ void audit_log_task_info(struct audit_buffer *ab)
>  EXPORT_SYMBOL(audit_log_task_info);
>  
>  /**
> - * audit_log_link_denied - report a link restriction denial
> - * @operation: specific link operation
> + * audit_log_path_denied - report a path restriction denial
> + * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc)
> + * @operation: specific operation name
>   */
> -void audit_log_link_denied(const char *operation)
> +void audit_log_path_denied(int type, const char *operation)
>  {
>  	struct audit_buffer *ab;
>  
>  	if (!audit_enabled || audit_dummy_context())
>  		return;
>  
> -	/* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
> -	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_LINK);
> +	/* Generate log with subject, operation, outcome. */
> +	ab = audit_log_start(audit_context(), GFP_KERNEL, type);
>  	if (!ab)
>  		return;
>  	audit_log_format(ab, "op=%s", operation);
> -- 
> 2.17.1
> 
> 
> -- 
> Kees Cook
Paul Moore Sept. 26, 2019, 3:31 p.m. UTC | #2
On Wed, Sep 25, 2019 at 5:02 PM Kees Cook <keescook@chromium.org> wrote:
>
> This renames the very specific audit_log_link_denied() to
> audit_log_path_denied() and adds the AUDIT_* type as an argument. This
> allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
> report the fifo/regular file creation restrictions that were introduced
> in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and
> regular files"). Without this change, discovering that the restriction
> is enabled can be very challenging:
> https://lore.kernel.org/lkml/CA+jJMxvkqjXHy3DnV5MVhFTL2RUhg0WQ-XVFW3ngDQOdkFq0PA@mail.gmail.com
>
> Reported-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> This is not a complete fix because reporting was broken in commit
> 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> audit_dummy_context")
> which specifically goes against the intention of these records: they
> should _always_ be reported. If auditing isn't enabled, they should be
> ratelimited.
>
> Instead of using audit, should this just go back to using
> pr_ratelimited()?

I'm going to ignore the rename and other aspects of this patch for the
moment so we can focus on the topic of if/when/how these records
should be emitted by the kernel.

Unfortunately, people tend to get very upset if audit emits *any*
records when they haven't explicitly enabled audit, the significance
of the record doesn't seem to matter, which is why you see patches
like 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
audit_dummy_context").  We could consider converting some records to
printk()s, rate-limited or not, but we need to balance this with the
various security certifications which audit was created to satisfy.
In some cases a printk() isn't sufficient.

Steve is probably the only one who really keeps track of the various
auditing requirements of the different security certifications; what
say you Steve on this issue with ANOM_CREAT records?
Steve Grubb Sept. 30, 2019, 1:50 p.m. UTC | #3
On Thursday, September 26, 2019 11:31:32 AM EDT Paul Moore wrote:
> On Wed, Sep 25, 2019 at 5:02 PM Kees Cook <keescook@chromium.org> wrote:
> > This renames the very specific audit_log_link_denied() to
> > audit_log_path_denied() and adds the AUDIT_* type as an argument. This
> > allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
> > report the fifo/regular file creation restrictions that were introduced
> > in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and
> > regular files"). Without this change, discovering that the restriction
> > is enabled can be very challenging:
> > https://lore.kernel.org/lkml/CA+jJMxvkqjXHy3DnV5MVhFTL2RUhg0WQ-XVFW3ngDQO
> > dkFq0PA@mail.gmail.com
> > 
> > Reported-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
> > Signed-off-by: Kees Cook <keescook@chromium.org>
> > ---
> > This is not a complete fix because reporting was broken in commit
> > 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> > audit_dummy_context")
> > which specifically goes against the intention of these records: they
> > should _always_ be reported. If auditing isn't enabled, they should be
> > ratelimited.
> > 
> > Instead of using audit, should this just go back to using
> > pr_ratelimited()?
> 
> I'm going to ignore the rename and other aspects of this patch for the
> moment so we can focus on the topic of if/when/how these records
> should be emitted by the kernel.
> 
> Unfortunately, people tend to get very upset if audit emits *any*
> records when they haven't explicitly enabled audit, the significance
> of the record doesn't seem to matter, which is why you see patches
> like 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> audit_dummy_context").  We could consider converting some records to
> printk()s, rate-limited or not, but we need to balance this with the
> various security certifications which audit was created to satisfy.
> In some cases a printk() isn't sufficient.
> 
> Steve is probably the only one who really keeps track of the various
> auditing requirements of the different security certifications; what
> say you Steve on this issue with ANOM_CREAT records?

Common Criteria and other security standards I track do not call out for 
anomoly detection. So, there are no requirements on this. That said, we do 
have other anomaly detections because they give early warning that something 
strange is happening. I think adding this event is a nice improvement as long 
as it obeys audit_enabled before emitting an event - for example, look at the 
AUDIT_ANOM_ABEND event.

-Steve
Kees Cook Sept. 30, 2019, 6:29 p.m. UTC | #4
On Mon, Sep 30, 2019 at 09:50:00AM -0400, Steve Grubb wrote:
> On Thursday, September 26, 2019 11:31:32 AM EDT Paul Moore wrote:
> > On Wed, Sep 25, 2019 at 5:02 PM Kees Cook <keescook@chromium.org> wrote:
> > > This renames the very specific audit_log_link_denied() to
> > > audit_log_path_denied() and adds the AUDIT_* type as an argument. This
> > > allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
> > > report the fifo/regular file creation restrictions that were introduced
> > > in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and
> > > regular files"). Without this change, discovering that the restriction
> > > is enabled can be very challenging:
> > > https://lore.kernel.org/lkml/CA+jJMxvkqjXHy3DnV5MVhFTL2RUhg0WQ-XVFW3ngDQO
> > > dkFq0PA@mail.gmail.com
> > > 
> > > Reported-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
> > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > > ---
> > > This is not a complete fix because reporting was broken in commit
> > > 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> > > audit_dummy_context")
> > > which specifically goes against the intention of these records: they
> > > should _always_ be reported. If auditing isn't enabled, they should be
> > > ratelimited.
> > > 
> > > Instead of using audit, should this just go back to using
> > > pr_ratelimited()?
> > 
> > I'm going to ignore the rename and other aspects of this patch for the
> > moment so we can focus on the topic of if/when/how these records
> > should be emitted by the kernel.
> > 
> > Unfortunately, people tend to get very upset if audit emits *any*
> > records when they haven't explicitly enabled audit, the significance
> > of the record doesn't seem to matter, which is why you see patches
> > like 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> > audit_dummy_context").  We could consider converting some records to
> > printk()s, rate-limited or not, but we need to balance this with the
> > various security certifications which audit was created to satisfy.
> > In some cases a printk() isn't sufficient.
> > 
> > Steve is probably the only one who really keeps track of the various
> > auditing requirements of the different security certifications; what
> > say you Steve on this issue with ANOM_CREAT records?
> 
> Common Criteria and other security standards I track do not call out for 
> anomoly detection. So, there are no requirements on this. That said, we do 
> have other anomaly detections because they give early warning that something 
> strange is happening. I think adding this event is a nice improvement as long 
> as it obeys audit_enabled before emitting an event - for example, look at the 
> AUDIT_ANOM_ABEND event.

Okay, so the patch is good as-is? (The "report things always" issue I
will deal with separately. For now I'd just like to gain this anomaly
detection corner case...)

Paul, what do you see as next steps here?
Paul Moore Oct. 1, 2019, 5:31 a.m. UTC | #5
On Mon, Sep 30, 2019 at 2:29 PM Kees Cook <keescook@chromium.org> wrote:
> On Mon, Sep 30, 2019 at 09:50:00AM -0400, Steve Grubb wrote:
> > On Thursday, September 26, 2019 11:31:32 AM EDT Paul Moore wrote:
> > > On Wed, Sep 25, 2019 at 5:02 PM Kees Cook <keescook@chromium.org> wrote:
> > > > This renames the very specific audit_log_link_denied() to
> > > > audit_log_path_denied() and adds the AUDIT_* type as an argument. This
> > > > allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
> > > > report the fifo/regular file creation restrictions that were introduced
> > > > in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and
> > > > regular files"). Without this change, discovering that the restriction
> > > > is enabled can be very challenging:
> > > > https://lore.kernel.org/lkml/CA+jJMxvkqjXHy3DnV5MVhFTL2RUhg0WQ-XVFW3ngDQO
> > > > dkFq0PA@mail.gmail.com
> > > >
> > > > Reported-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
> > > > Signed-off-by: Kees Cook <keescook@chromium.org>
> > > > ---
> > > > This is not a complete fix because reporting was broken in commit
> > > > 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> > > > audit_dummy_context")
> > > > which specifically goes against the intention of these records: they
> > > > should _always_ be reported. If auditing isn't enabled, they should be
> > > > ratelimited.
> > > >
> > > > Instead of using audit, should this just go back to using
> > > > pr_ratelimited()?
> > >
> > > I'm going to ignore the rename and other aspects of this patch for the
> > > moment so we can focus on the topic of if/when/how these records
> > > should be emitted by the kernel.
> > >
> > > Unfortunately, people tend to get very upset if audit emits *any*
> > > records when they haven't explicitly enabled audit, the significance
> > > of the record doesn't seem to matter, which is why you see patches
> > > like 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> > > audit_dummy_context").  We could consider converting some records to
> > > printk()s, rate-limited or not, but we need to balance this with the
> > > various security certifications which audit was created to satisfy.
> > > In some cases a printk() isn't sufficient.
> > >
> > > Steve is probably the only one who really keeps track of the various
> > > auditing requirements of the different security certifications; what
> > > say you Steve on this issue with ANOM_CREAT records?
> >
> > Common Criteria and other security standards I track do not call out for
> > anomoly detection. So, there are no requirements on this. That said, we do
> > have other anomaly detections because they give early warning that something
> > strange is happening. I think adding this event is a nice improvement as long
> > as it obeys audit_enabled before emitting an event - for example, look at the
> > AUDIT_ANOM_ABEND event.
>
> Okay, so the patch is good as-is? (The "report things always" issue I
> will deal with separately. For now I'd just like to gain this anomaly
> detection corner case...)
>
> Paul, what do you see as next steps here?

I'll reply back on the original post so I can more easily comment on
the details of patch.
Paul Moore Oct. 1, 2019, 5:37 a.m. UTC | #6
On Wed, Sep 25, 2019 at 5:02 PM Kees Cook <keescook@chromium.org> wrote:
>
> This renames the very specific audit_log_link_denied() to
> audit_log_path_denied() and adds the AUDIT_* type as an argument. This
> allows for the creation of the new AUDIT_ANOM_CREAT that can be used to
> report the fifo/regular file creation restrictions that were introduced
> in commit 30aba6656f61 ("namei: allow restricted O_CREAT of FIFOs and
> regular files"). Without this change, discovering that the restriction
> is enabled can be very challenging:
> https://lore.kernel.org/lkml/CA+jJMxvkqjXHy3DnV5MVhFTL2RUhg0WQ-XVFW3ngDQOdkFq0PA@mail.gmail.com
>
> Reported-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> This is not a complete fix because reporting was broken in commit
> 15564ff0a16e ("audit: make ANOM_LINK obey audit_enabled and
> audit_dummy_context")
> which specifically goes against the intention of these records: they
> should _always_ be reported. If auditing isn't enabled, they should be
> ratelimited.
>
> Instead of using audit, should this just go back to using
> pr_ratelimited()?
> ---
>  fs/namei.c                 |  7 +++++--
>  include/linux/audit.h      |  5 +++--
>  include/uapi/linux/audit.h |  1 +
>  kernel/audit.c             | 11 ++++++-----
>  4 files changed, 15 insertions(+), 9 deletions(-)

...

> diff --git a/fs/namei.c b/fs/namei.c
> index 671c3c1a3425..0e60f81e1d5a 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -1031,6 +1031,9 @@ static int may_create_in_sticky(struct dentry * const dir,
>             (dir->d_inode->i_mode & 0020 &&
>              ((sysctl_protected_fifos >= 2 && S_ISFIFO(inode->i_mode)) ||
>               (sysctl_protected_regular >= 2 && S_ISREG(inode->i_mode))))) {
> +               audit_log_path_denied(AUDIT_ANOM_CREAT,
> +                                     S_ISFIFO(inode->i_mode) ? "fifo"
> +                                                             : "regular");
>                 return -EACCES;

Other callers typically pass an operation value more closely tied to
the syscall/function name, and that somewhat makes sense since the
syscall/function name is often verb-ish.  The code above, while
helpful in the sense that it distinguishes between types of inodes, it
doesn't give much indication about the "operation" which failed.  I'm
open to suggestions, but something like "sticky_create_fifo" seems
more consistent which current usage.  Thoughts?

> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index aee3dc9eb378..b3715e2ee1c5 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -217,7 +218,7 @@ static inline void audit_log_d_path(struct audit_buffer *ab,
>  { }
>  static inline void audit_log_key(struct audit_buffer *ab, char *key)
>  { }
> -static inline void audit_log_link_denied(const char *string)
> +static inline void audit_log_path_denied(int type, const char *string);
>  { }

I probably wouldn't make you respin just for this, but since you may
need to respin this anyway, you might as well fix the above.

Patch
diff mbox series

diff --git a/fs/namei.c b/fs/namei.c
index 671c3c1a3425..0e60f81e1d5a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -925,7 +925,7 @@  static inline int may_follow_link(struct nameidata *nd)
 		return -ECHILD;
 
 	audit_inode(nd->name, nd->stack[0].link.dentry, 0);
-	audit_log_link_denied("follow_link");
+	audit_log_path_denied(AUDIT_ANOM_LINK, "follow_link");
 	return -EACCES;
 }
 
@@ -993,7 +993,7 @@  static int may_linkat(struct path *link)
 	if (safe_hardlink_source(inode) || inode_owner_or_capable(inode))
 		return 0;
 
-	audit_log_link_denied("linkat");
+	audit_log_path_denied(AUDIT_ANOM_LINK, "linkat");
 	return -EPERM;
 }
 
@@ -1031,6 +1031,9 @@  static int may_create_in_sticky(struct dentry * const dir,
 	    (dir->d_inode->i_mode & 0020 &&
 	     ((sysctl_protected_fifos >= 2 && S_ISFIFO(inode->i_mode)) ||
 	      (sysctl_protected_regular >= 2 && S_ISREG(inode->i_mode))))) {
+		audit_log_path_denied(AUDIT_ANOM_CREAT,
+				      S_ISFIFO(inode->i_mode) ? "fifo"
+							      : "regular");
 		return -EACCES;
 	}
 	return 0;
diff --git a/include/linux/audit.h b/include/linux/audit.h
index aee3dc9eb378..b3715e2ee1c5 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -156,7 +156,8 @@  extern void		    audit_log_d_path(struct audit_buffer *ab,
 					     const struct path *path);
 extern void		    audit_log_key(struct audit_buffer *ab,
 					  char *key);
-extern void		    audit_log_link_denied(const char *operation);
+extern void		    audit_log_path_denied(int type,
+						  const char *operation);
 extern void		    audit_log_lost(const char *message);
 
 extern int audit_log_task_context(struct audit_buffer *ab);
@@ -217,7 +218,7 @@  static inline void audit_log_d_path(struct audit_buffer *ab,
 { }
 static inline void audit_log_key(struct audit_buffer *ab, char *key)
 { }
-static inline void audit_log_link_denied(const char *string)
+static inline void audit_log_path_denied(int type, const char *string);
 { }
 static inline int audit_log_task_context(struct audit_buffer *ab)
 {
diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
index c89c6495983d..3ad935527177 100644
--- a/include/uapi/linux/audit.h
+++ b/include/uapi/linux/audit.h
@@ -143,6 +143,7 @@ 
 #define AUDIT_ANOM_PROMISCUOUS      1700 /* Device changed promiscuous mode */
 #define AUDIT_ANOM_ABEND            1701 /* Process ended abnormally */
 #define AUDIT_ANOM_LINK		    1702 /* Suspicious use of file links */
+#define AUDIT_ANOM_CREAT	    1703 /* Suspicious file creation */
 #define AUDIT_INTEGRITY_DATA	    1800 /* Data integrity verification */
 #define AUDIT_INTEGRITY_METADATA    1801 /* Metadata integrity verification */
 #define AUDIT_INTEGRITY_STATUS	    1802 /* Integrity enable status */
diff --git a/kernel/audit.c b/kernel/audit.c
index da8dc0db5bd3..ed7402ac81b6 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -2155,18 +2155,19 @@  void audit_log_task_info(struct audit_buffer *ab)
 EXPORT_SYMBOL(audit_log_task_info);
 
 /**
- * audit_log_link_denied - report a link restriction denial
- * @operation: specific link operation
+ * audit_log_path_denied - report a path restriction denial
+ * @type: audit message type (AUDIT_ANOM_LINK, AUDIT_ANOM_CREAT, etc)
+ * @operation: specific operation name
  */
-void audit_log_link_denied(const char *operation)
+void audit_log_path_denied(int type, const char *operation)
 {
 	struct audit_buffer *ab;
 
 	if (!audit_enabled || audit_dummy_context())
 		return;
 
-	/* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
-	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_LINK);
+	/* Generate log with subject, operation, outcome. */
+	ab = audit_log_start(audit_context(), GFP_KERNEL, type);
 	if (!ab)
 		return;
 	audit_log_format(ab, "op=%s", operation);