linux/fs
Steven Rostedt (Google) 1a6edfc7be eventfs: Hold eventfs_mutex when calling callback functions
commit 44365329f8 upstream.

The callback function that is used to create inodes and dentries is not
protected by anything and the data that is passed to it could become
stale. After eventfs_remove_dir() is called by the tracing system, it is
free to remove the events that are associated to that directory.
Unfortunately, that means the callbacks must not be called after that.

     CPU0				CPU1
     ----				----
 eventfs_root_lookup() {
				 eventfs_remove_dir() {
				      mutex_lock(&event_mutex);
				      ei->is_freed = set;
				      mutex_unlock(&event_mutex);
				 }
				 kfree(event_call);

    for (...) {
      entry = &ei->entries[i];
      r = entry->callback() {
          call = data;		// call == event_call above
          if (call->flags ...)

 [ USE AFTER FREE BUG ]

The safest way to protect this is to wrap the callback with:

 mutex_lock(&eventfs_mutex);
 if (!ei->is_freed)
     r = entry->callback();
 else
     r = -1;
 mutex_unlock(&eventfs_mutex);

This will make sure that the callback will not be called after it is
freed. But now it needs to be known that the callback is called while
holding internal eventfs locks, and that it must not call back into the
eventfs / tracefs system. There's no reason it should anyway, but document
that as well.

Link: https://lore.kernel.org/all/CA+G9fYu9GOEbD=rR5eMR-=HJ8H6rMsbzDC2ZY5=Y50WpWAE7_Q@mail.gmail.com/
Link: https://lkml.kernel.org/r/20231101172649.906696613@goodmis.org

Cc: Ajay Kaher <akaher@vmware.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 5790b1fb3d ("eventfs: Remove eventfs_file and just use eventfs_inode")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:25:21 +01:00
..
9p 9p: Fix initialisation of netfs_inode for 9p 2024-02-05 20:14:32 +00:00
adfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
affs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
afs afs: fix the usage of read_seqbegin_or_lock() in afs_find_server*() 2024-02-05 20:14:16 +00:00
autofs v6.6-vfs.autofs 2023-08-28 11:39:14 -07:00
befs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
bfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
btrfs btrfs: don't drop extent_map for free space inode on write error 2024-02-23 09:24:48 +01:00
cachefiles - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
ceph ceph: prevent use-after-free in encode_cap_msg() 2024-02-23 09:25:16 +01:00
coda v6.6-vfs.ctime 2023-08-28 09:31:32 -07:00
configfs configfs: convert to ctime accessor functions 2023-07-13 10:28:05 +02:00
cramfs v6.6-vfs.super 2023-08-28 11:04:18 -07:00
crypto
debugfs debugfs: fix automount d_fsdata usage 2024-01-20 11:51:37 +01:00
devpts v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
dlm dlm: use kernel_connect() and kernel_bind() 2024-01-31 16:18:54 -08:00
ecryptfs ecryptfs: Reject casefold directory inodes 2024-02-05 20:14:17 +00:00
efivarfs efivarfs: Free s_fs_info on unmount 2024-01-25 15:35:15 -08:00
efs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
erofs erofs: fix ztailpacking for subpage compressed blocks 2024-02-05 20:14:16 +00:00
exfat exfat: support handle zero-size directory 2023-11-28 17:19:44 +00:00
exportfs exportfs: remove kernel-doc warnings in exportfs 2023-08-29 17:45:22 -04:00
ext2 ext2: Fix ki_pos update for DIO buffered-io fallback case 2023-12-08 08:52:19 +01:00
ext4 ext4: avoid bb_free and bb_fragments inconsistency in mb_free_blocks() 2024-02-23 09:25:05 +01:00
f2fs f2fs: fix to tag gcing flag on page during block migration 2024-02-05 20:14:28 +00:00
fat for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
freevxfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
fscache netfs, fscache: Prevent Oops in fscache_put_cache() 2024-01-31 16:19:01 -08:00
fuse fuse: dax: set fc->dax to NULL in fuse_dax_conn_free() 2023-12-20 17:01:52 +01:00
gfs2 gfs2: fix kernel BUG in gfs2_quota_cleanup 2024-01-25 15:35:17 -08:00
hfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hfsplus for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hostfs hostfs: convert to ctime accessor functions 2023-07-24 10:30:00 +02:00
hpfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
hugetlbfs mm: hugetlb pages should not be reserved by shmat() if SHM_NORESERVE 2024-02-23 09:25:16 +01:00
iomap iomap: fix short copy in iomap_write_iter() 2023-10-19 09:41:36 -07:00
isofs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
jbd2 jbd2: fix soft lockup in journal_finish_inode_data_buffers() 2024-01-20 11:51:43 +01:00
jffs2 jffs2: convert to ctime accessor functions 2023-07-24 10:30:01 +02:00
jfs jfs: fix array-index-out-of-bounds in diNewExt 2024-02-05 20:14:16 +00:00
kernfs fs/kernfs/dir: obey S_ISGID 2024-02-05 20:14:32 +00:00
lockd SUNRPC: Add enum svc_auth_status 2023-08-29 17:45:22 -04:00
minix for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
netfs netfs: Only call folio_start_fscache() one time for each folio 2023-09-18 12:03:46 -07:00
nfs pNFS: Fix the pnfs block driver's calculation of layoutget size 2024-01-25 15:35:18 -08:00
nfs_common
nfsd nfsd: fix RELEASE_LOCKOWNER 2024-01-31 16:19:06 -08:00
nilfs2 nilfs2: fix hang in nilfs_lookup_dirty_data_buffers() 2024-02-23 09:25:11 +01:00
nls nls: Hide new NLS_UCS2_UTILS 2023-08-31 12:07:34 -05:00
notify fanotify: limit reporting of event with non-decodeable file handles 2023-10-19 16:19:20 +02:00
ntfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
ntfs3 fs/ntfs3: Fix an NULL dereference bug 2024-02-16 19:10:52 +01:00
ocfs2 Many ext4 and jbd2 cleanups and bug fixes for v6.6-rc1. 2023-08-31 15:18:15 -07:00
omfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
openpromfs openpromfs: convert to ctime accessor functions 2023-07-24 10:30:03 +02:00
orangefs fs: drop the timespec64 argument from update_time 2023-08-11 09:04:57 +02:00
overlayfs fs: Pass AT_GETATTR_NOSEC flag to getattr interface function 2023-12-03 07:33:03 +01:00
proc fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand() 2024-02-23 09:25:17 +01:00
pstore pstore/ram: Fix crash when setting number of cpus to an odd number 2024-02-05 20:14:16 +00:00
qnx4 for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
qnx6 for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
quota quota: explicitly forbid quota files from being encrypted 2023-11-28 17:20:04 +00:00
ramfs ramfs: convert to ctime accessor functions 2023-07-24 10:30:04 +02:00
reiserfs reiserfs: Avoid touching renamed directory if parent does not change 2024-02-05 20:14:26 +00:00
romfs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
smb smb: Fix regression in writes when non-standard maximum write size negotiated 2024-02-23 09:25:13 +01:00
squashfs squashfs: convert to ctime accessor functions 2023-07-24 10:30:05 +02:00
sysfs
sysv for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
tracefs eventfs: Hold eventfs_mutex when calling callback functions 2024-02-23 09:25:21 +01:00
ubifs ubifs: ubifs_symlink: Fix memleak of inode->i_link in error path 2024-01-31 16:18:56 -08:00
udf \n 2023-08-30 12:10:50 -07:00
ufs for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
unicode
vboxsf v6.6-vfs.ctime 2023-08-28 09:31:32 -07:00
verity fsverity: skip PKCS#7 parser when keyring is empty 2023-08-20 10:33:43 -07:00
xfs xfs: respect the stable writes flag on the RT device 2024-02-16 19:10:46 +01:00
zonefs zonefs: Improve error handling 2024-02-23 09:25:13 +01:00
aio.c aio: Annotate struct kioctx_table with __counted_by 2023-09-20 14:22:01 +02:00
anon_inodes.c
attr.c v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
bad_inode.c fs: drop the timespec64 argument from update_time 2023-08-11 09:04:57 +02:00
binfmt_elf_fdpic.c fs: binfmt_elf_efpic: fix personality for ELF-FDPIC 2023-09-29 17:20:45 -07:00
binfmt_elf_test.c
binfmt_elf.c Merge branch 'expand-stack' 2023-06-28 20:35:21 -07:00
binfmt_flat.c
binfmt_misc.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
binfmt_script.c
buffer.c iomap: add a workaround for racy i_size updates on block devices 2023-09-25 08:55:00 -07:00
char_dev.c
compat_binfmt_elf.c
coredump.c v6.5/vfs.misc 2023-06-26 09:50:21 -07:00
d_path.c
dax.c mm: convert DAX lock/unlock page to lock/unlock folio 2024-01-10 17:16:53 +01:00
dcache.c fast_dput(): handle underflows gracefully 2024-02-05 20:14:26 +00:00
direct-io.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
drop_caches.c fs: drop_caches: draining pages before dropping caches 2023-08-18 10:12:11 -07:00
eventfd.c eventfd: prevent underflow for eventfd semaphores 2023-07-11 11:41:34 +02:00
eventpoll.c epoll: simplify ep_alloc() 2023-07-26 14:56:07 +02:00
exec.c exec: Fix error handling in begin_new_exec() 2024-01-31 16:19:06 -08:00
fcntl.c fcntl: Cast commands with int args explicitly 2023-07-10 14:36:11 +02:00
fhandle.c
file_table.c fs: use __fput_sync in close(2) 2023-08-08 19:36:51 +02:00
file.c v6.6-vfs.misc 2023-08-28 10:17:14 -07:00
filesystems.c
fs_context.c fs: factor out vfs_parse_monolithic_sep() helper 2023-10-12 18:53:36 +03:00
fs_parser.c
fs_pin.c
fs_struct.c kill do_each_thread() 2023-08-21 13:46:25 -07:00
fs_types.c
fs-writeback.c writeback, cgroup: switch inodes with dirty timestamps to release dying cgwbs 2023-11-20 11:58:52 +01:00
fsopen.c fs: add FSCONFIG_CMD_CREATE_EXCL 2023-08-14 18:48:02 +02:00
init.c
inode.c filemap: add a per-mapping stable writes flag 2023-12-03 07:33:03 +01:00
internal.h for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
ioctl.c lsm: new security_file_ioctl_compat() hook 2024-01-31 16:18:54 -08:00
Kconfig for-6.6/block-2023-08-28 2023-08-29 20:21:42 -07:00
Kconfig.binfmt riscv: support the elf-fdpic binfmt loader 2023-08-23 14:17:43 -07:00
kernel_read_file.c fs: Fix kernel-doc warnings 2023-08-19 12:12:12 +02:00
libfs.c fs: new accessor methods for atime and mtime 2024-01-05 15:19:40 +01:00
locks.c NFSD 6.6 Release Notes 2023-08-31 15:32:18 -07:00
Makefile fs: add CONFIG_BUFFER_HEAD 2023-08-02 09:13:09 -06:00
mbcache.c
mnt_idmapping.c
mount.h
mpage.c
namei.c rename(): fix the locking of subdirectories 2024-01-31 16:18:57 -08:00
namespace.c fs: relax mount_setattr() permission checks 2024-02-23 09:25:15 +01:00
nsfs.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
open.c cred: get rid of CONFIG_DEBUG_CREDENTIALS 2023-12-20 17:01:51 +01:00
pipe.c pipe: wakeup wr_wait after setting max_usage 2024-01-31 16:19:09 -08:00
pnode.c
pnode.h
posix_acl.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
proc_namespace.c
read_write.c fs: Fix one kernel-doc comment 2023-08-15 08:32:45 +02:00
readdir.c vfs: get rid of old '->iterate' directory operation 2023-08-06 15:08:35 +02:00
remap_range.c
select.c
seq_file.c
signalfd.c
splice.c - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") 2023-08-29 14:25:26 -07:00
stack.c fs: convert to ctime accessor functions 2023-07-13 10:28:04 +02:00
stat.c fs: Pass AT_GETATTR_NOSEC flag to getattr interface function 2023-12-03 07:33:03 +01:00
statfs.c
super.c fs: export sget_dev() 2023-08-31 12:47:15 +02:00
sync.c
sysctls.c
timerfd.c
userfaultfd.c mm: userfaultfd: remove stale comment about core dump locking 2023-08-24 16:20:27 -07:00
utimes.c
xattr.c tmpfs,xattr: GFP_KERNEL_ACCOUNT for simple xattrs 2023-08-22 10:57:46 +02:00