Petr Mladek writes:
Both "model" and "strflags" are passed to "%s" even when one or both
are NULL.
It is safe because vsprintf() would detect the NULL pointer and print
"(null)". But it is a kernel-specific feature and compiler warns
about it:
<warning>
In file included from include/linux/kernel.h:19,
from arch/x86/include/asm/percpu.h:27,
from arch/x86/include/asm/current.h:6,
from include/linux/sched.h:12,
from include/linux/blkdev.h:5,
from drivers/scsi/scsi_devinfo.c:3:
drivers/scsi/scsi_devinfo.c: In function 'scsi_dev_info_list_add_str':
include/linux/printk.h:434:44: warning: '%s' directive argument is null [-Wformat-overflow=]
434 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__)
| ^
include/linux/printk.h:430:3: note: in definition of macro 'printk_index_wrap'
430 | _p_func(_fmt, ##__VA_ARGS__); \
| ^~~~~~~
drivers/scsi/scsi_devinfo.c:551:4: note: in expansion of macro 'printk'
551 | printk(KERN_ERR "%s: bad dev info string '%s' '%s'"
| ^~~~~~
drivers/scsi/scsi_devinfo.c:552:14: note: format string is defined here
552 | " '%s'\n", __func__, vendor, model,
| ^~
</warning>
Do not rely on the kernel specific behavior and print the message a safe way.
Acked-by: Chris Down <chris@xxxxxxxxxxxxxx>
While I agree with the other thread that in reality this is ok, it's worth
reducing the addition to LKP noise for now and worrying about that later.
Thanks!
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202401112002.AOjwMNM0-lkp@xxxxxxxxx/
Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
---
Note: The patch is only compile tested.
drivers/scsi/scsi_devinfo.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
index 3fcaf10a9dfe..ba7237e83863 100644
--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -551,9 +551,9 @@ static int scsi_dev_info_list_add_str(char *dev_list)
if (model)
strflags = strsep(&next, next_check);
if (!model || !strflags) {
- printk(KERN_ERR "%s: bad dev info string '%s' '%s'"
- " '%s'\n", __func__, vendor, model,
- strflags);
+ pr_err("%s: bad dev info string '%s' '%s' '%s'\n",
+ __func__, vendor, model ? model : "",
+ strflags ? strflags : "");
res = -EINVAL;
} else
res = scsi_dev_info_list_add(0 /* compatible */, vendor,
--
2.43.0
