kernel/trace/blktrace.c:664 blk_trace_setup() error: strcpy() 'buts2.name' too large for 'buts.name' (64 vs 32)

kernel/trace/blktrace.c:664 blk_trace_setup() error: strcpy() 'buts2.name' too large for 'buts.name' (64 vs 32)

[Dan Carpenter]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   18f7fcd5e69a04df57b563360b88be72471d6b62
commit: 113cbd62824afdf62d2f3f092809cf37cc7f1dd8 blktrace: pass blk_user_trace2 to setup functions
date:   3 months ago
config: s390-randconfig-r073-20260202 (https://download.01.org/0day-ci/archive/20260202/202602020718.GUEIRyG9-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9b8addffa70cee5b2acc5454712d9cf78ce45710)
smatch version: v0.5.0-8994-gd50c5a4c

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202602020718.GUEIRyG9-lkp@intel.com/

smatch warnings:
kernel/trace/blktrace.c:664 blk_trace_setup() error: strcpy() 'buts2.name' too large for 'buts.name' (64 vs 32)

vim +664 kernel/trace/blktrace.c

b769a2f409e7a3 kernel/trace/blktrace.c Ming Lei           2024-11-28  631  int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
b769a2f409e7a3 kernel/trace/blktrace.c Ming Lei           2024-11-28  632  		    struct block_device *bdev,
b769a2f409e7a3 kernel/trace/blktrace.c Ming Lei           2024-11-28  633  		    char __user *arg)
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  634  {
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  635  	struct blk_user_trace_setup2 buts2;
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  636  	struct blk_user_trace_setup buts;
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  637  	struct blk_trace *bt;
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  638  	int ret;
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  639  
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  640  	ret = copy_from_user(&buts, arg, sizeof(buts));
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  641  	if (ret)
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  642  		return -EFAULT;
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  643  
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  644  	if (!buts.buf_size || !buts.buf_nr)
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  645  		return -EINVAL;
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  646  
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  647  	buts2 = (struct blk_user_trace_setup2) {
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  648  		.act_mask = buts.act_mask,
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  649  		.buf_size = buts.buf_size,
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  650  		.buf_nr = buts.buf_nr,
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  651  		.start_lba = buts.start_lba,
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  652  		.end_lba = buts.end_lba,
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  653  		.pid = buts.pid,
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  654  	};
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  655  
b769a2f409e7a3 kernel/trace/blktrace.c Ming Lei           2024-11-28  656  	mutex_lock(&q->debugfs_mutex);
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  657  	bt = blk_trace_setup_prepare(q, name, dev, buts.buf_size, buts.buf_nr,
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  658  				     bdev);
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  659  	if (IS_ERR(bt)) {
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  660  		mutex_unlock(&q->debugfs_mutex);
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  661  		return PTR_ERR(bt);
42da88a724d8a3 kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  662  	}
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22  663  	blk_trace_setup_finalize(q, name, 1, bt, &buts2);
113cbd62824afd kernel/trace/blktrace.c Johannes Thumshirn 2025-10-22 @664  	strcpy(buts.name, buts2.name);

BLKTRACE_BDEV_SIZE2 is 64. BLKTRACE_BDEV_SIZE is 32.  The kbuild bot
doesn't have cross function analsys, but in linux-next the callers
only pass BLKTRACE_BDEV_SIZE size strings.

b769a2f409e7a3 kernel/trace/blktrace.c Ming Lei           2024-11-28  665  	mutex_unlock(&q->debugfs_mutex);
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  666  
9a8c28c8311e30 kernel/trace/blktrace.c Dmitry Monakhov    2010-02-27  667  	if (copy_to_user(arg, &buts, sizeof(buts))) {
b769a2f409e7a3 kernel/trace/blktrace.c Ming Lei           2024-11-28  668  		blk_trace_remove(q);
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  669  		return -EFAULT;
9a8c28c8311e30 kernel/trace/blktrace.c Dmitry Monakhov    2010-02-27  670  	}
171044d449611c block/blktrace.c        Arnd Bergmann      2007-10-09  671  	return 0;
1f2cac107c591c kernel/trace/blktrace.c Jens Axboe         2017-11-05  672  }

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https://github.com/intel/lkp-tests/wiki