kernel/linux.git/fs/configfs, branch v5.10.257

configfs: Do not override creating attribute file failure in populate_attrs()

2025-06-27T10:04:11+00:00

commit f830edbae247b89228c3e09294151b21e0dc849c upstream. populate_attrs() may override failure for creating attribute files by success for creating subsequent bin attribute files, and have wrong return value. Fix by creating bin attribute files under successfully creating attribute files. Fixes: 03607ace807b ("configfs: implement binary attributes") Cc: stable@vger.kernel.org Reviewed-by: Joel Becker Reviewed-by: Breno Leitao Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250507-fix_configfs-v3-2-fe2d96de8dc4@quicinc.com Signed-off-by: Andreas Hindborg Signed-off-by: Greg Kroah-Hartman

Revert "configfs: fix a race in configfs_lookup()"

2023-09-21T07:45:15+00:00

This reverts commit c709c7ca020a52ef6530733a9a5f014bd6b71937 which is commit c42dd069be8dfc9b2239a5c89e73bbd08ab35de0 upstream. It was backported incorrectly, and will come back later in a way that actually works. Cc: Sishuai Gong Cc: Christoph Hellwig Cc: Kyle Zeng Reported-by: Guenter Roeck Link: https://lore.kernel.org/r/27f978f3-11ca-6054-5160-ab66d4c918bc@roeck-us.net Signed-off-by: Greg Kroah-Hartman

configfs: fix a race in configfs_lookup()

2023-09-19T10:20:03+00:00

commit c42dd069be8dfc9b2239a5c89e73bbd08ab35de0 upstream. When configfs_lookup() is executing list_for_each_entry(), it is possible that configfs_dir_lseek() is calling list_del(). Some unfortunate interleavings of them can cause a kernel NULL pointer dereference error Thread 1 Thread 2 //configfs_dir_lseek() //configfs_lookup() list_del(&cursor->s_sibling); list_for_each_entry(sd, ...) Fix this by grabbing configfs_dirent_lock in configfs_lookup() while iterating ->s_children. Signed-off-by: Sishuai Gong Signed-off-by: Christoph Hellwig Signed-off-by: Kyle Zeng Signed-off-by: Greg Kroah-Hartman

configfs: fix possible memory leak in configfs_create_dir()

2023-01-14T09:15:37+00:00

[ Upstream commit c65234b283a65cfbfc94619655e820a5e55199eb ] kmemleak reported memory leaks in configfs_create_dir(): unreferenced object 0xffff888009f6af00 (size 192): comm "modprobe", pid 3777, jiffies 4295537735 (age 233.784s) backtrace: kmem_cache_alloc (mm/slub.c:3250 mm/slub.c:3256 mm/slub.c:3263 mm/slub.c:3273) new_fragment (./include/linux/slab.h:600 fs/configfs/dir.c:163) configfs_register_subsystem (fs/configfs/dir.c:1857) basic_write (drivers/hwtracing/stm/p_basic.c:14) stm_p_basic do_one_initcall (init/main.c:1296) do_init_module (kernel/module/main.c:2455) ... unreferenced object 0xffff888003ba7180 (size 96): comm "modprobe", pid 3777, jiffies 4295537735 (age 233.784s) backtrace: kmem_cache_alloc (mm/slub.c:3250 mm/slub.c:3256 mm/slub.c:3263 mm/slub.c:3273) configfs_new_dirent (./include/linux/slab.h:723 fs/configfs/dir.c:194) configfs_make_dirent (fs/configfs/dir.c:248) configfs_create_dir (fs/configfs/dir.c:296) configfs_attach_group.isra.28 (fs/configfs/dir.c:816 fs/configfs/dir.c:852) configfs_register_subsystem (fs/configfs/dir.c:1881) basic_write (drivers/hwtracing/stm/p_basic.c:14) stm_p_basic do_one_initcall (init/main.c:1296) do_init_module (kernel/module/main.c:2455) ... This is because the refcount is not correct in configfs_make_dirent(). For normal stage, the refcount is changing as: configfs_register_subsystem() configfs_create_dir() configfs_make_dirent() configfs_new_dirent() # set s_count = 1 dentry->d_fsdata = configfs_get(sd); # s_count = 2 ... configfs_unregister_subsystem() configfs_remove_dir() remove_dir() configfs_remove_dirent() # s_count = 1 dput() ... *dentry_unlink_inode()* configfs_d_iput() # s_count = 0, release However, if we failed in configfs_create(): configfs_register_subsystem() configfs_create_dir() configfs_make_dirent() # s_count = 2 ... configfs_create() # fail ->out_remove: configfs_remove_dirent(dentry) configfs_put(sd) # s_count = 1 return PTR_ERR(inode); There is no inode in the error path, so the configfs_d_iput() is lost and makes sd and fragment memory leaked. To fix this, when we failed in configfs_create(), manually call configfs_put(sd) to keep the refcount correct. Fixes: 7063fbf22611 ("[PATCH] configfs: User-driven configuration filesystem") Signed-off-by: Chen Zhongjin Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin

configfs: fix a race in configfs_{,un}register_subsystem()

2022-03-02T10:42:52+00:00

[ Upstream commit 84ec758fb2daa236026506868c8796b0500c047d ] When configfs_register_subsystem() or configfs_unregister_subsystem() is executing link_group() or unlink_group(), it is possible that two processes add or delete list concurrently. Some unfortunate interleavings of them can cause kernel panic. One of cases is: A --> B --> C --> D A <-- B <-- C <-- D delete list_head *B | delete list_head *C --------------------------------|----------------------------------- configfs_unregister_subsystem | configfs_unregister_subsystem unlink_group | unlink_group unlink_obj | unlink_obj list_del_init | list_del_init __list_del_entry | __list_del_entry __list_del | __list_del // next == C | next->prev = prev | | next->prev = prev prev->next = next | | // prev == B | prev->next = next Fix this by adding mutex when calling link_group() or unlink_group(), but parent configfs_subsystem is NULL when config_item is root. So I create a mutex configfs_subsystem_mutex. Fixes: 7063fbf22611 ("[PATCH] configfs: User-driven configuration filesystem") Signed-off-by: ChenXiaoSong Signed-off-by: Laibin Qiu Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin

fsnotify: fix fsnotify hooks in pseudo filesystems

2022-02-01T16:25:39+00:00

commit 29044dae2e746949ad4b9cbdbfb248994d1dcdb4 upstream. Commit 49246466a989 ("fsnotify: move fsnotify_nameremove() hook out of d_delete()") moved the fsnotify delete hook before d_delete() so fsnotify will have access to a positive dentry. This allowed a race where opening the deleted file via cached dentry is now possible after receiving the IN_DELETE event. To fix the regression in pseudo filesystems, convert d_delete() calls to d_drop() (see commit 46c46f8df9aa ("devpts_pty_kill(): don't bother with d_delete()") and move the fsnotify hook after d_drop(). Add a missing fsnotify_unlink() hook in nfsdfs that was found during the audit of fsnotify hooks in pseudo filesystems. Note that the fsnotify hooks in simple_recursive_removal() follow d_invalidate(), so they require no change. Link: https://lore.kernel.org/r/20220120215305.282577-2-amir73il@gmail.com Reported-by: Ivan Delalande Link: https://lore.kernel.org/linux-fsdevel/YeNyzoDM5hP5LtGW@visor/ Fixes: 49246466a989 ("fsnotify: move fsnotify_nameremove() hook out of d_delete()") Cc: stable@vger.kernel.org # v5.3+ Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

configfs: fix memleak in configfs_release_bin_file

2021-07-14T14:56:48+00:00

[ Upstream commit 3c252b087de08d3cb32468b54a158bd7ad0ae2f7 ] When reading binary attributes in progress, buffer->bin_buffer is setup in configfs_read_bin_file() but never freed. Fixes: 03607ace807b4 ("configfs: implement binary attributes") Signed-off-by: Chung-Chiang Cheng [hch: move the vfree rather than duplicating it] Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin

configfs: fix a use-after-free in __configfs_open_file

2021-03-17T16:06:34+00:00

[ Upstream commit 14fbbc8297728e880070f7b077b3301a8c698ef9 ] Commit b0841eefd969 ("configfs: provide exclusion between IO and removals") uses ->frag_dead to mark the fragment state, thus no bothering with extra refcount on config_item when opening a file. The configfs_get_config_item was removed in __configfs_open_file, but not with config_item_put. So the refcount on config_item will lost its balance, causing use-after-free issues in some occasions like this: Test: 1. Mount configfs on /config with read-only items: drwxrwx--- 289 root root 0 2021-04-01 11:55 /config drwxr-xr-x 2 root root 0 2021-04-01 11:54 /config/a --w--w--w- 1 root root 4096 2021-04-01 11:53 /config/a/1.txt ...... 2. Then run: for file in /config do echo $file grep -R 'key' $file done 3. __configfs_open_file will be called in parallel, the first one got called will do: if (file->f_mode & FMODE_READ) { if (!(inode->i_mode & S_IRUGO)) goto out_put_module; config_item_put(buffer->item); kref_put() package_details_release() kfree() the other one will run into use-after-free issues like this: BUG: KASAN: use-after-free in __configfs_open_file+0x1bc/0x3b0 Read of size 8 at addr fffffff155f02480 by task grep/13096 CPU: 0 PID: 13096 Comm: grep VIP: 00 Tainted: G W 4.14.116-kasan #1 TGID: 13096 Comm: grep Call trace: dump_stack+0x118/0x160 kasan_report+0x22c/0x294 __asan_load8+0x80/0x88 __configfs_open_file+0x1bc/0x3b0 configfs_open_file+0x28/0x34 do_dentry_open+0x2cc/0x5c0 vfs_open+0x80/0xe0 path_openat+0xd8c/0x2988 do_filp_open+0x1c4/0x2fc do_sys_open+0x23c/0x404 SyS_openat+0x38/0x48 Allocated by task 2138: kasan_kmalloc+0xe0/0x1ac kmem_cache_alloc_trace+0x334/0x394 packages_make_item+0x4c/0x180 configfs_mkdir+0x358/0x740 vfs_mkdir2+0x1bc/0x2e8 SyS_mkdirat+0x154/0x23c el0_svc_naked+0x34/0x38 Freed by task 13096: kasan_slab_free+0xb8/0x194 kfree+0x13c/0x910 package_details_release+0x524/0x56c kref_put+0xc4/0x104 config_item_put+0x24/0x34 __configfs_open_file+0x35c/0x3b0 configfs_open_file+0x28/0x34 do_dentry_open+0x2cc/0x5c0 vfs_open+0x80/0xe0 path_openat+0xd8c/0x2988 do_filp_open+0x1c4/0x2fc do_sys_open+0x23c/0x404 SyS_openat+0x38/0x48 el0_svc_naked+0x34/0x38 To fix this issue, remove the config_item_put in __configfs_open_file to balance the refcount of config_item. Fixes: b0841eefd969 ("configfs: provide exclusion between IO and removals") Signed-off-by: Daiyue Zhang Signed-off-by: Yi Chen Signed-off-by: Ge Qiu Reviewed-by: Chao Yu Acked-by: Al Viro Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin

fs: configfs: delete repeated words in comments

2020-10-16T18:11:19+00:00

Drop duplicated words {the, that} in comments. Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Cc: Joel Becker Cc: Christoph Hellwig Link: https://lkml.kernel.org/r/20200811021826.25032-1-rdunlap@infradead.org Signed-off-by: Linus Torvalds

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva