This is a note to let you know that I've just added the patch titled
eeprom: idt_89hpesx: uninitialized data in idt_dbgfs_csr_write()
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
eeprom-idt_89hpesx-uninitialized-data-in-idt_dbgfs_c.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a73164fa167fe0ea571c824308d8de8bfbfb31e5
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Fri Jul 8 16:46:38 2022 +0300
eeprom: idt_89hpesx: uninitialized data in idt_dbgfs_csr_write()
[ Upstream commit 71d46f1ff2212ced4852c7e77c5176382a1bdcec ]
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@xxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Link: https://lore.kernel.org/r/Ysg1Pu/nzSMe3r1q@kili
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/misc/eeprom/idt_89hpesx.c b/drivers/misc/eeprom/idt_89hpesx.c
index b0cff4b152da..7f430742ce2b 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 */
