X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=drivers%2Fchar%2Fnvram.c;h=5eb83c3ca20de35be340031015a93495ae19e12b;hb=0f4533979473a456a8adb3869365e12c7a99cf65;hp=7cf4518c030f2b3a9293c23dd599643739758d1c;hpb=83cb16727085b18191f45eb0ede6bf1f97d67a7a;p=mirror_ubuntu-jammy-kernel.git

diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 7cf4518c030f..5eb83c3ca20d 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -110,6 +110,7 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
+#include <linux/smp_lock.h>
 
 #include <asm/system.h>
 
@@ -263,10 +264,16 @@ static ssize_t nvram_write(struct file *file, const char __user *buf,
 	unsigned char contents[NVRAM_BYTES];
 	unsigned i = *ppos;
 	unsigned char *tmp;
-	int len;
 
-	len = (NVRAM_BYTES - i) < count ? (NVRAM_BYTES - i) : count;
-	if (copy_from_user(contents, buf, len))
+	if (i >= NVRAM_BYTES)
+		return 0;	/* Past EOF */
+
+	if (count > NVRAM_BYTES - i)
+		count = NVRAM_BYTES - i;
+	if (count > NVRAM_BYTES)
+		return -EFAULT;	/* Can't happen, but prove it to gcc */
+
+	if (copy_from_user(contents, buf, count))
 		return -EFAULT;
 
 	spin_lock_irq(&rtc_lock);
@@ -274,7 +281,7 @@ static ssize_t nvram_write(struct file *file, const char __user *buf,
 	if (!__nvram_check_checksum())
 		goto checksum_err;
 
-	for (tmp = contents; count-- > 0 && i < NVRAM_BYTES; ++i, ++tmp)
+	for (tmp = contents; count--; ++i, ++tmp)
 		__nvram_write_byte(*tmp, i);
 
 	__nvram_set_checksum();