From: Herbert Xu Date: Mon, 7 Apr 2025 04:57:54 +0000 (+0800) Subject: crypto: ccp - Silence may-be-uninitialized warning in sev_ioctl_do_pdh_export X-Git-Tag: v6.16-rc1~206^2~315 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af7e23c616f523b1c4d1f5f0cd7f9852fa4aa24f;p=thirdparty%2Fkernel%2Flinux.git crypto: ccp - Silence may-be-uninitialized warning in sev_ioctl_do_pdh_export The recent reordering of code in sev_ioctl_do_pdh_export triggered a false-positive may-be-uninitialized warning from gcc: In file included from ../include/linux/sched/task.h:13, from ../include/linux/sched/signal.h:9, from ../include/linux/rcuwait.h:6, from ../include/linux/percpu-rwsem.h:7, from ../include/linux/fs.h:34, from ../include/linux/compat.h:17, from ../arch/x86/include/asm/ia32.h:7, from ../arch/x86/include/asm/elf.h:10, from ../include/linux/elf.h:6, from ../include/linux/module.h:19, from ../drivers/crypto/ccp/sev-dev.c:11: In function ‘copy_to_user’, inlined from ‘sev_ioctl_do_pdh_export’ at ../drivers/crypto/ccp/sev-dev.c:2036:7, inlined from ‘sev_ioctl’ at ../drivers/crypto/ccp/sev-dev.c:2249:9: ../include/linux/uaccess.h:225:16: warning: ‘input_cert_chain_address’ may be used uninitialized [-Wmaybe-uninitialized] 225 | return _copy_to_user(to, from, n); | ^~~~~~~~~~~~~~~~~~~~~~~~~~ ../drivers/crypto/ccp/sev-dev.c: In function ‘sev_ioctl’: ../drivers/crypto/ccp/sev-dev.c:1961:22: note: ‘input_cert_chain_address’ was declared here 1961 | void __user *input_cert_chain_address; | ^~~~~~~~~~~~~~~~~~~~~~~~ Silence it by moving the initialisation of the variables in question prior to the NULL check. Signed-off-by: Herbert Xu Acked-by: Tom Lendacky Signed-off-by: Herbert Xu --- diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 980b3d296dc6e..19fb51558a7d1 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -1964,15 +1964,15 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable) memset(&data, 0, sizeof(data)); + input_pdh_cert_address = (void __user *)input.pdh_cert_address; + input_cert_chain_address = (void __user *)input.cert_chain_address; + /* Userspace wants to query the certificate length. */ if (!input.pdh_cert_address || !input.pdh_cert_len || !input.cert_chain_address) goto cmd; - input_pdh_cert_address = (void __user *)input.pdh_cert_address; - input_cert_chain_address = (void __user *)input.cert_chain_address; - /* Allocate a physically contiguous buffer to store the PDH blob. */ if (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) return -EFAULT;