drivers/crypto/ccp/ccp-ops.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Annotating a local pointer variable, which will be assigned with the
kmalloc-family functions, with the `__cleanup(kfree)` attribute will
make the address of the local variable, rather than the address returned
by kmalloc, passed to kfree directly and lead to a crash due to invalid
deallocation of stack address. According to other places in the repo,
the correct usage should be `__free(kfree)`. The code coincidentally
compiled because the parameter type `void *` of kfree is compatible with
the desired type `struct { ... } **`.
Fixes: a71475582ada ("crypto: ccp - reduce stack usage in ccp_run_aes_gcm_cmd")
Signed-off-by: Ella Ma <alansnape3058@gmail.com>
Acked-by: Tom Lendacky <thomas.lendacky@gmail.com>
---
Changes in v2:
- Update the subject prefix as suggested by Markus
I don't have the machine to actually test the changed place. So I tried
locally with a simple test module. The crash happens right when the
module is being loaded.
```C
#include <linux/init.h>
#include <linux/module.h>
MODULE_LICENSE("GPL");
static int __init custom_init(void) {
printk(KERN_INFO "Crash reproduce for drivers/crypto/ccp/ccp-ops.c");
int *p __cleanup(kfree) = kzalloc(sizeof(int), GFP_KERNEL);
*p = 42;
return 0;
}
static void __exit custom_exit(void) {}
module_init(custom_init);
module_exit(custom_exit);
```
BESIDES, scripts/checkpatch.pl reports a coding style issue originally
existing in the code, `sizeof *wa`, I fixed this together in this patch.
drivers/crypto/ccp/ccp-ops.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/crypto/ccp/ccp-ops.c b/drivers/crypto/ccp/ccp-ops.c
index d78865d9d5f0..f80a92006666 100644
--- a/drivers/crypto/ccp/ccp-ops.c
+++ b/drivers/crypto/ccp/ccp-ops.c
@@ -642,7 +642,7 @@ ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
struct ccp_data dst;
struct ccp_data aad;
struct ccp_op op;
- } *wa __cleanup(kfree) = kzalloc(sizeof *wa, GFP_KERNEL);
+ } *wa __free(kfree) = kzalloc(sizeof(*wa), GFP_KERNEL);
unsigned int dm_offset;
unsigned int authsize;
unsigned int jobid;
--
2.34.1
On Fri, 2026-01-09 at 16:17 +0100, Ella Ma wrote:
> Annotating a local pointer variable, which will be assigned with the
> kmalloc-family functions, with the `__cleanup(kfree)` attribute will
> make the address of the local variable, rather than the address returned
> by kmalloc, passed to kfree directly and lead to a crash due to invalid
> deallocation of stack address. According to other places in the repo,
> the correct usage should be `__free(kfree)`. The code coincidentally
> compiled because the parameter type `void *` of kfree is compatible with
> the desired type `struct { ... } **`.
>
> Fixes: a71475582ada ("crypto: ccp - reduce stack usage in ccp_run_aes_gcm_cmd")
Perhaps this one too?
drivers/gpu/drm/xe/xe_guc_ct.c: char *buf __cleanup(kfree) = kmalloc(SZ_4K, GFP_NOWAIT);
On Fri, Jan 09, 2026 at 04:17:24PM +0100, Ella Ma wrote:
> Annotating a local pointer variable, which will be assigned with the
> kmalloc-family functions, with the `__cleanup(kfree)` attribute will
> make the address of the local variable, rather than the address returned
> by kmalloc, passed to kfree directly and lead to a crash due to invalid
> deallocation of stack address. According to other places in the repo,
> the correct usage should be `__free(kfree)`. The code coincidentally
> compiled because the parameter type `void *` of kfree is compatible with
> the desired type `struct { ... } **`.
>
> Fixes: a71475582ada ("crypto: ccp - reduce stack usage in ccp_run_aes_gcm_cmd")
> Signed-off-by: Ella Ma <alansnape3058@gmail.com>
> Acked-by: Tom Lendacky <thomas.lendacky@gmail.com>
> ---
>
> Changes in v2:
> - Update the subject prefix as suggested by Markus
>
>
> I don't have the machine to actually test the changed place. So I tried
> locally with a simple test module. The crash happens right when the
> module is being loaded.
>
> ```C
> #include <linux/init.h>
> #include <linux/module.h>
> MODULE_LICENSE("GPL");
> static int __init custom_init(void) {
> printk(KERN_INFO "Crash reproduce for drivers/crypto/ccp/ccp-ops.c");
> int *p __cleanup(kfree) = kzalloc(sizeof(int), GFP_KERNEL);
> *p = 42;
> return 0;
> }
> static void __exit custom_exit(void) {}
> module_init(custom_init);
> module_exit(custom_exit);
> ```
>
> BESIDES, scripts/checkpatch.pl reports a coding style issue originally
> existing in the code, `sizeof *wa`, I fixed this together in this patch.
>
> drivers/crypto/ccp/ccp-ops.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Patch applied. Thanks.
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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