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authorDan Carpenter <dan.carpenter@oracle.com>2022-07-08 16:46:38 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-07-14 16:53:19 +0200
commit71d46f1ff2212ced4852c7e77c5176382a1bdcec (patch)
tree9226c6185ec84a77f8ef44713a1ff4e714c68512 /drivers/misc
parent2a3c8f8a4494343f5942b780b3f6295307a07b6e (diff)
downloadlinux-71d46f1ff2212ced4852c7e77c5176382a1bdcec.tar.bz2
eeprom: idt_89hpesx: uninitialized data in idt_dbgfs_csr_write()
The simple_write_to_buffer() function will return positive/success if it is able to write a single byte anywhere within the buffer. However that potentially leaves a lot of the buffer uninitialized. In this code it's better to return 0 if the offset is non-zero. This code is not written to support partial writes. And then return -EFAULT if the buffer is not completely initialized. Fixes: cfad6425382e ("eeprom: Add IDT 89HPESx EEPROM/CSR driver") Reviewed-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/Ysg1Pu/nzSMe3r1q@kili Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/eeprom/idt_89hpesx.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/misc/eeprom/idt_89hpesx.c b/drivers/misc/eeprom/idt_89hpesx.c
index 42eac114edd7..9aec3338e37d 100644
--- a/drivers/misc/eeprom/idt_89hpesx.c
+++ b/drivers/misc/eeprom/idt_89hpesx.c
@@ -909,14 +909,18 @@ static ssize_t idt_dbgfs_csr_write(struct file *filep, const char __user *ubuf,
u32 csraddr, csrval;
char *buf;
+ if (*offp)
+ return 0;
+
/* Copy data from User-space */
buf = kmalloc(count + 1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
- ret = simple_write_to_buffer(buf, count, offp, ubuf, count);
- if (ret < 0)
+ if (copy_from_user(buf, ubuf, count)) {
+ ret = -EFAULT;
goto free_buf;
+ }
buf[count] = 0;
/* Find position of colon in the buffer */