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From:   Kees Cook <keescook@chromium.org>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Kees Cook <keescook@chromium.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Jason Gunthorpe <jgg@ziepe.ca>, Nishanth Menon <nm@ti.com>,
        Michael Kelley <mikelley@microsoft.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Won Chung <wonchung@google.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH] driver core: Add __alloc_size hint to devm allocators
Date:   Tue, 18 Oct 2022 00:34:47 -0700
Message-Id: <20221018073430.never.551-kees@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Mark the devm_*alloc()-family of allocations with appropriate
__alloc_size() hints so the compiler can attempt to reason about buffer
lengths from allocations.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Nishanth Menon <nm@ti.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Won Chung <wonchung@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/linux/device.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/linux/device.h b/include/linux/device.h
index 424b55df0272..a1cbbab9a57a 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -197,9 +197,9 @@ void devres_remove_group(struct device *dev, void *id);
 int devres_release_group(struct device *dev, void *id);
 
 /* managed devm_k.alloc/kfree for device drivers */
-void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __malloc;
+void *devm_kmalloc(struct device *dev, size_t size, gfp_t gfp) __alloc_size(2);
 void *devm_krealloc(struct device *dev, void *ptr, size_t size,
-		    gfp_t gfp) __must_check;
+		    gfp_t gfp) __must_check __realloc_size(3);
 __printf(3, 0) char *devm_kvasprintf(struct device *dev, gfp_t gfp,
 				     const char *fmt, va_list ap) __malloc;
 __printf(3, 4) char *devm_kasprintf(struct device *dev, gfp_t gfp,
@@ -226,7 +226,8 @@ static inline void *devm_kcalloc(struct device *dev,
 void devm_kfree(struct device *dev, const void *p);
 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp) __malloc;
 const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp);
-void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp);
+void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
+	__alloc_size(3);
 
 unsigned long devm_get_free_pages(struct device *dev,
 				  gfp_t gfp_mask, unsigned int order);
-- 
2.34.1