See the goto fail on line 738.
julia
---------- Forwarded message ----------
Date: Thu, 19 Oct 2023 02:04:17 +0800
From: kernel test robot <lkp@xxxxxxxxx>
To: oe-kbuild@xxxxxxxxxxxxxxx
Cc: lkp@xxxxxxxxx, Julia Lawall <julia.lawall@xxxxxxxx>
Subject: [linux-next:master 8657/13299] fs/tracefs/event_inode.c:782:11-21:
ERROR: ei is NULL but dereferenced.
BCC: lkp@xxxxxxxxx
CC: oe-kbuild-all@xxxxxxxxxxxxxxx
CC: Linux Memory Management List <linux-mm@xxxxxxxxx>
TO: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: 2dac75696c6da3c848daa118a729827541c89d33
commit: 5790b1fb3d672d9a1fe3881a7181dfdbe741568f [8657/13299] eventfs: Remove eventfs_file and just use eventfs_inode
:::::: branch date: 14 hours ago
:::::: commit date: 2 weeks ago
config: i386-randconfig-052-20231018 (https://download.01.org/0day-ci/archive/20231019/202310190142.oAl4P1Iw-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20231019/202310190142.oAl4P1Iw-lkp@xxxxxxxxx/reproduce)
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@xxxxxxxxx>
| Reported-by: Julia Lawall <julia.lawall@xxxxxxxx>
| Closes: https://lore.kernel.org/r/202310190142.oAl4P1Iw-lkp@xxxxxxxxx/
cocci warnings: (new ones prefixed by >>)
>> fs/tracefs/event_inode.c:782:11-21: ERROR: ei is NULL but dereferenced.
vim +782 fs/tracefs/event_inode.c
c1504e51023847 Ajay Kaher 2023-07-28 710
c1504e51023847 Ajay Kaher 2023-07-28 711 /**
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 712) * eventfs_create_events_dir - create the top level events directory
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 713) * @name: The name of the top level directory to create.
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 714) * @parent: Parent dentry for this file in the tracefs directory.
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 715) * @entries: A list of entries that represent the files under this directory
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 716) * @size: The number of @entries
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 717) * @data: The default data to pass to the files (an entry may override it).
c1504e51023847 Ajay Kaher 2023-07-28 718 *
c1504e51023847 Ajay Kaher 2023-07-28 719 * This function creates the top of the trace event directory.
c1504e51023847 Ajay Kaher 2023-07-28 720 */
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 721) struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry *parent,
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 722) const struct eventfs_entry *entries,
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 723) int size, void *data)
c1504e51023847 Ajay Kaher 2023-07-28 724 {
c1504e51023847 Ajay Kaher 2023-07-28 725 struct dentry *dentry = tracefs_start_creating(name, parent);
c1504e51023847 Ajay Kaher 2023-07-28 726 struct eventfs_inode *ei;
c1504e51023847 Ajay Kaher 2023-07-28 727 struct tracefs_inode *ti;
c1504e51023847 Ajay Kaher 2023-07-28 728 struct inode *inode;
c1504e51023847 Ajay Kaher 2023-07-28 729
e24709454c4582 Steven Rostedt (Google 2023-09-05 730) if (security_locked_down(LOCKDOWN_TRACEFS))
e24709454c4582 Steven Rostedt (Google 2023-09-05 731) return NULL;
e24709454c4582 Steven Rostedt (Google 2023-09-05 732)
c1504e51023847 Ajay Kaher 2023-07-28 733 if (IS_ERR(dentry))
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 734) return (struct eventfs_inode *)dentry;
c1504e51023847 Ajay Kaher 2023-07-28 735
c1504e51023847 Ajay Kaher 2023-07-28 736 ei = kzalloc(sizeof(*ei), GFP_KERNEL);
c1504e51023847 Ajay Kaher 2023-07-28 737 if (!ei)
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 738) goto fail;
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 739)
c1504e51023847 Ajay Kaher 2023-07-28 740 inode = tracefs_get_inode(dentry->d_sb);
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 741) if (unlikely(!inode))
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 742) goto fail;
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 743)
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 744) if (size) {
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 745) ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 746) if (!ei->d_children)
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 747) goto fail;
c1504e51023847 Ajay Kaher 2023-07-28 748 }
c1504e51023847 Ajay Kaher 2023-07-28 749
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 750) ei->dentry = dentry;
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 751) ei->entries = entries;
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 752) ei->nr_entries = size;
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 753) ei->data = data;
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 754) ei->name = kstrdup_const(name, GFP_KERNEL);
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 755) if (!ei->name)
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 756) goto fail;
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 757)
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 758) INIT_LIST_HEAD(&ei->children);
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 759) INIT_LIST_HEAD(&ei->list);
c1504e51023847 Ajay Kaher 2023-07-28 760
c1504e51023847 Ajay Kaher 2023-07-28 761 ti = get_tracefs(inode);
9879e5e1c528d1 Steven Rostedt (Google 2023-09-06 762) ti->flags |= TRACEFS_EVENT_INODE | TRACEFS_EVENT_TOP_INODE;
c1504e51023847 Ajay Kaher 2023-07-28 763 ti->private = ei;
c1504e51023847 Ajay Kaher 2023-07-28 764
c1504e51023847 Ajay Kaher 2023-07-28 765 inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
c1504e51023847 Ajay Kaher 2023-07-28 766 inode->i_op = &eventfs_root_dir_inode_operations;
c1504e51023847 Ajay Kaher 2023-07-28 767 inode->i_fop = &eventfs_file_operations;
c1504e51023847 Ajay Kaher 2023-07-28 768
c1504e51023847 Ajay Kaher 2023-07-28 769 /* directory inodes start off with i_nlink == 2 (for "." entry) */
c1504e51023847 Ajay Kaher 2023-07-28 770 inc_nlink(inode);
c1504e51023847 Ajay Kaher 2023-07-28 771 d_instantiate(dentry, inode);
c1504e51023847 Ajay Kaher 2023-07-28 772 inc_nlink(dentry->d_parent->d_inode);
c1504e51023847 Ajay Kaher 2023-07-28 773 fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 774) tracefs_end_creating(dentry);
88f349b4a83aab Ajay Kaher 2023-07-28 775
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 776) /* Will call dput when the directory is removed */
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 777) dget(dentry);
88f349b4a83aab Ajay Kaher 2023-07-28 778
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 779) return ei;
88f349b4a83aab Ajay Kaher 2023-07-28 780
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 781) fail:
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 @782) kfree(ei->d_children);
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 783) kfree(ei);
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 784) tracefs_failed_creating(dentry);
5790b1fb3d672d Steven Rostedt (Google 2023-10-04 785) return ERR_PTR(-ENOMEM);
88f349b4a83aab Ajay Kaher 2023-07-28 786 }
5bdcd5f5331a27 Ajay Kaher 2023-07-28 787
--
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