crypto: ccp - Fix use-after-free on error path

In the error path of sev_tsm_init_locked(), the code dereferences 't'
after it has been freed with kfree(). The pr_err() statement attempts
to access t->tio_en and t->tio_init_done after the memory has been
released.

Move the pr_err() call before kfree(t) to access the fields while the
memory is still valid.

This issue reported by Smatch static analyser

Fixes:4be423572da1 ("crypto/ccp: Implement SEV-TIO PCIe IDE (phase1)")
Signed-off-by: Alper Ak <alperyasinak1@gmail.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/ccp/sev-dev-tsm.c b/drivers/crypto/ccp/sev-dev-tsm.c
index adc9542ae806d01455a29ec9ef9e8f7cff5e2a6d..b07ae529b5910ef70b821e57815eede63346313d 100644 (file)
--- a/drivers/crypto/ccp/sev-dev-tsm.c
+++ b/drivers/crypto/ccp/sev-dev-tsm.c
@@ -378,9 +378,9 @@ void sev_tsm_init_locked(struct sev_device *sev, void *tio_status_page)
        return;
 
 error_exit:
-       kfree(t);
        pr_err("Failed to enable SEV-TIO: ret=%d en=%d initdone=%d SEV=%d\n",
               ret, t->tio_en, t->tio_init_done, boot_cpu_has(X86_FEATURE_SEV));
+       kfree(t);
 }
 
 void sev_tsm_uninit(struct sev_device *sev)