Hi Faiyaz, url: https://github.com/0day-ci/linux/commits/Faiyaz-Mohammed/mm-slub-move-sysfs-slab-alloc-free-interfaces-to-debugfs/20210506-182420 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 8404c9fbc84b741f66cff7d4934a25dd2c344452 config: i386-randconfig-m021-20210506 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> smatch warnings: mm/slub.c:5891 slab_debugfs_start() warn: possible memory leak of 'spos' vim +/spos +5891 mm/slub.c 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5877 static void *slab_debugfs_start(struct seq_file *seq, loff_t *ppos) 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5878 { 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5879 struct kmem_cache_node *n; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5880 struct kmem_cache *s; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5881 enum track_item alloc; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5882 int node; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5883 loff_t *spos = kmalloc(sizeof(loff_t), GFP_KERNEL); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Generally avoid putting functions which can fail in the declaration block. Allocations inside the declaration block are a tiny percent of declarations over all but they are an outsize source of static checker bugs. 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5884 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5885 s = seq->file->f_inode->i_private; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5886 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5887 if (!spos) 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5888 return NULL; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5889 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5890 if (!(s->flags & SLAB_STORE_USER)) 88e180b99466c1 Faiyaz Mohammed 2021-05-06 @5891 return ERR_PTR(-EOPNOTSUPP); "spos" is leaked. 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5892 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5893 if (*ppos == 0) { 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5894 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5895 t.count = 0; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5896 t.max = 0; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5897 t.loc = NULL; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5898 if (strcmp(seq->file->f_path.dentry->d_name.name, "alloc_traces") == 0) 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5899 alloc = TRACK_ALLOC; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5900 else 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5901 alloc = TRACK_FREE; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5902 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5903 if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5904 GFP_KERNEL)) { 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5905 seq_puts(seq, "Out of memory\n"); 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5906 return ERR_PTR(-ENOMEM); 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5907 } 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5908 /* Push back cpu slabs */ 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5909 flush_all(s); 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5910 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5911 for_each_kmem_cache_node(s, node, n) { 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5912 unsigned long flags; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5913 struct page *page; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5914 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5915 if (!atomic_long_read(&n->nr_slabs)) 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5916 continue; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5917 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5918 spin_lock_irqsave(&n->list_lock, flags); 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5919 list_for_each_entry(page, &n->partial, slab_list) 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5920 process_slab(&t, s, page, alloc); 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5921 list_for_each_entry(page, &n->full, slab_list) 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5922 process_slab(&t, s, page, alloc); 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5923 spin_unlock_irqrestore(&n->list_lock, flags); 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5924 } 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5925 } 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5926 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5927 if (*ppos < t.count) { 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5928 *spos = *ppos; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5929 return spos; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5930 } 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5931 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5932 kfree(spos); 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5933 return NULL; 88e180b99466c1 Faiyaz Mohammed 2021-05-06 5934 } --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
