From bbb4013947fa5d9b2a65efdbfb08020abb060a18 Mon Sep 17 00:00:00 2001 From: Akshay Gupta Date: Wed, 16 Jul 2025 11:07:28 +0000 Subject: [PATCH] misc: amd-sbi: Address copy_to/from_user() warning reported in smatch Smatch warnings are reported for below commit, Commit bb13a84ed6b7 ("misc: amd-sbi: Add support for CPUID protocol") from Apr 28, 2025 (linux-next), leads to the following Smatch static checker warning: drivers/misc/amd-sbi/rmi-core.c:376 apml_rmi_reg_xfer() warn: maybe return -EFAULT instead of the bytes remaining? drivers/misc/amd-sbi/rmi-core.c:394 apml_mailbox_xfer() warn: maybe return -EFAULT instead of the bytes remaining? drivers/misc/amd-sbi/rmi-core.c:411 apml_cpuid_xfer() warn: maybe return -EFAULT instead of the bytes remaining? drivers/misc/amd-sbi/rmi-core.c:428 apml_mcamsr_xfer() warn: maybe return -EFAULT instead of the bytes remaining? copy_to/from_user() returns number of bytes, not copied. In case data not copied, return "-EFAULT". Additionally, fixes the "-EPROTOTYPE" error return as intended. Fixes: 35ac2034db72 ("misc: amd-sbi: Add support for AMD_SBI IOCTL") Fixes: bb13a84ed6b7 ("misc: amd-sbi: Add support for CPUID protocol") Fixes: 69b1ba83d21c ("misc: amd-sbi: Add support for read MCA register protocol") Fixes: cf141287b774 ("misc: amd-sbi: Add support for register xfer") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/all/aDVyO8ByVsceybk9@stanley.mountain/ Reviewed-by: Naveen Krishna Chatradhi Signed-off-by: Akshay Gupta Link: https://lore.kernel.org/r/20250716110729.2193725-2-akshay.gupta@amd.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/amd-sbi/rmi-core.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/misc/amd-sbi/rmi-core.c b/drivers/misc/amd-sbi/rmi-core.c index 3570f3b269a95..9048517c088c7 100644 --- a/drivers/misc/amd-sbi/rmi-core.c +++ b/drivers/misc/amd-sbi/rmi-core.c @@ -372,7 +372,8 @@ static int apml_rmi_reg_xfer(struct sbrmi_data *data, mutex_unlock(&data->lock); if (msg.rflag && !ret) - return copy_to_user(arg, &msg, sizeof(struct apml_reg_xfer_msg)); + if (copy_to_user(arg, &msg, sizeof(struct apml_reg_xfer_msg))) + return -EFAULT; return ret; } @@ -390,7 +391,9 @@ static int apml_mailbox_xfer(struct sbrmi_data *data, struct apml_mbox_msg __use if (ret && ret != -EPROTOTYPE) return ret; - return copy_to_user(arg, &msg, sizeof(struct apml_mbox_msg)); + if (copy_to_user(arg, &msg, sizeof(struct apml_mbox_msg))) + return -EFAULT; + return ret; } static int apml_cpuid_xfer(struct sbrmi_data *data, struct apml_cpuid_msg __user *arg) @@ -407,7 +410,9 @@ static int apml_cpuid_xfer(struct sbrmi_data *data, struct apml_cpuid_msg __user if (ret && ret != -EPROTOTYPE) return ret; - return copy_to_user(arg, &msg, sizeof(struct apml_cpuid_msg)); + if (copy_to_user(arg, &msg, sizeof(struct apml_cpuid_msg))) + return -EFAULT; + return ret; } static int apml_mcamsr_xfer(struct sbrmi_data *data, struct apml_mcamsr_msg __user *arg) @@ -424,7 +429,9 @@ static int apml_mcamsr_xfer(struct sbrmi_data *data, struct apml_mcamsr_msg __us if (ret && ret != -EPROTOTYPE) return ret; - return copy_to_user(arg, &msg, sizeof(struct apml_mcamsr_msg)); + if (copy_to_user(arg, &msg, sizeof(struct apml_mcamsr_msg))) + return -EFAULT; + return ret; } static long sbrmi_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) -- 2.47.2