From bf2c7bf5c48303b76f20537238292571e6aa29f3 Mon Sep 17 00:00:00 2001 From: Pasha Tatashin Date: Sat, 29 Nov 2025 20:09:19 -0500 Subject: [PATCH] liveupdate: luo_core: fix redundant bound check in luo_ioctl() The kernel test robot reported a Smatch warning: kernel/liveupdate/luo_core.c:402 luo_ioctl() warn: unsigned 'nr' is never less than zero. This occurs because 'nr' is unsigned and LIVEUPDATE_CMD_BASE is currently defined as 0, making the check (nr < LIVEUPDATE_CMD_BASE) always false. Remove the explicit lower bound check. The logic remains correct because 'nr' is unsigned; if nr is less than LIVEUPDATE_CMD_BASE, the expression (nr - LIVEUPDATE_CMD_BASE) will wrap around to a large positive value. This will inevitably be larger than ARRAY_SIZE(luo_ioctl_ops) and be caught by the upper bound check. Link: https://lkml.kernel.org/r/20251130010919.1488230-1-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202511280300.6pvBmXUS-lkp@intel.com/ Reviewed-by: Mike Rapoport (Microsoft) Cc: David Matlack Cc: Pratyush Yadav Signed-off-by: Andrew Morton --- kernel/liveupdate/luo_core.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/liveupdate/luo_core.c b/kernel/liveupdate/luo_core.c index f7ecaf7740d19..944663d99dd9f 100644 --- a/kernel/liveupdate/luo_core.c +++ b/kernel/liveupdate/luo_core.c @@ -399,10 +399,8 @@ static long luo_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) int err; nr = _IOC_NR(cmd); - if (nr < LIVEUPDATE_CMD_BASE || - (nr - LIVEUPDATE_CMD_BASE) >= ARRAY_SIZE(luo_ioctl_ops)) { + if (nr - LIVEUPDATE_CMD_BASE >= ARRAY_SIZE(luo_ioctl_ops)) return -EINVAL; - } ucmd.ubuffer = (void __user *)arg; err = get_user(ucmd.user_size, (u32 __user *)ucmd.ubuffer); -- 2.47.3