A mirror of the official Linux kernel repository just in case
Go to file
Chao Yu be4edd1642
hfsplus: fix to avoid false alarm of circular locking
Syzbot report potential ABBA deadlock as below:

loop0: detected capacity change from 0 to 1024
======================================================
WARNING: possible circular locking dependency detected
6.9.0-syzkaller-10323-g8f6a15f095a6 #0 Not tainted
------------------------------------------------------
syz-executor171/5344 is trying to acquire lock:
ffff88807cb980b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x811/0xb50 fs/hfsplus/extents.c:595

but task is already holding lock:
ffff88807a930108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2da/0xb50 fs/hfsplus/extents.c:576

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       hfsplus_file_extend+0x21b/0x1b70 fs/hfsplus/extents.c:457
       hfsplus_bmap_reserve+0x105/0x4e0 fs/hfsplus/btree.c:358
       hfsplus_rename_cat+0x1d0/0x1050 fs/hfsplus/catalog.c:456
       hfsplus_rename+0x12e/0x1c0 fs/hfsplus/dir.c:552
       vfs_rename+0xbdb/0xf00 fs/namei.c:4887
       do_renameat2+0xd94/0x13f0 fs/namei.c:5044
       __do_sys_rename fs/namei.c:5091 [inline]
       __se_sys_rename fs/namei.c:5089 [inline]
       __x64_sys_rename+0x86/0xa0 fs/namei.c:5089
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&tree->tree_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       hfsplus_file_truncate+0x811/0xb50 fs/hfsplus/extents.c:595
       hfsplus_setattr+0x1ce/0x280 fs/hfsplus/inode.c:265
       notify_change+0xb9d/0xe70 fs/attr.c:497
       do_truncate+0x220/0x310 fs/open.c:65
       handle_truncate fs/namei.c:3308 [inline]
       do_open fs/namei.c:3654 [inline]
       path_openat+0x2a3d/0x3280 fs/namei.c:3807
       do_filp_open+0x235/0x490 fs/namei.c:3834
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
       do_sys_open fs/open.c:1421 [inline]
       __do_sys_creat fs/open.c:1497 [inline]
       __se_sys_creat fs/open.c:1491 [inline]
       __x64_sys_creat+0x123/0x170 fs/open.c:1491
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&HFSPLUS_I(inode)->extents_lock);
                               lock(&tree->tree_lock);
                               lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&tree->tree_lock);

This is a false alarm as tree_lock mutex are different, one is
from sbi->cat_tree, and another is from sbi->ext_tree:

Thread A			Thread B
- hfsplus_rename
 - hfsplus_rename_cat
  - hfs_find_init
   - mutext_lock(cat_tree->tree_lock)
				- hfsplus_setattr
				 - hfsplus_file_truncate
				  - mutex_lock(hip->extents_lock)
				  - hfs_find_init
				   - mutext_lock(ext_tree->tree_lock)
  - hfs_bmap_reserve
   - hfsplus_file_extend
    - mutex_lock(hip->extents_lock)

So, let's call mutex_lock_nested for tree_lock mutex lock, and pass
correct lock class for it.

Fixes: 31651c6071 ("hfsplus: avoid deadlock on file truncation")
Reported-by: syzbot+6030b3b1b9bf70e538c4@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-fsdevel/000000000000e37a4005ef129563@google.com
Cc: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20240607142304.455441-1-chao@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-06-21 11:41:04 +02:00
arch 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
block block-6.10-20240523 2024-05-23 13:44:47 -07:00
certs kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
crypto This push fixes a bug in the new ecc P521 code as well as a buggy 2024-05-20 08:47:54 -07:00
Documentation 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
drivers ipmi: Mostly updates for deprecated interfaces 2024-05-25 14:32:29 -07:00
fs hfsplus: fix to avoid false alarm of circular locking 2024-06-21 11:41:04 +02:00
include vfs: retire user_path_at_empty and drop empty arg from getname_flags 2024-06-05 17:03:57 +02:00
init Driver core changes for 6.10-rc1 2024-05-22 12:13:40 -07:00
io_uring vfs: retire user_path_at_empty and drop empty arg from getname_flags 2024-06-05 17:03:57 +02:00
ipc Mainly singleton patches, documented in their respective changelogs. 2024-05-19 14:02:03 -07:00
kernel fs: don't block i_writecount during exec 2024-06-03 15:52:10 +02:00
lib 16 hotfixes, 11 of which are cc:stable. 2024-05-25 15:10:33 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm tmpfs: don't interrupt fallocate with EINTR 2024-06-03 16:35:17 +02:00
net NFS client updates for Linux 6.10 2024-05-23 13:51:09 -07:00
rust LoongArch changes for v6.10 2024-05-22 09:43:07 -07:00
samples tracing/treewide: Remove second parameter of __assign_str() 2024-05-22 20:14:47 -04:00
scripts - A series ("kbuild: enable more warnings by default") from Arnd 2024-05-22 18:59:29 -07:00
security hardening fixes for v6.10-rc1 2024-05-24 08:33:44 -07:00
sound sound fixes for 6.10-rc1 2024-05-24 08:48:51 -07:00
tools Revert a patch causing a regression as described in the cset: 2024-05-26 09:54:26 -07:00
usr kbuild: use $(src) instead of $(srctree)/$(src) for source directory 2024-05-10 04:34:52 +09:00
virt The usual shower of singleton fixes and minor series all over MM, 2024-05-19 09:21:03 -07:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: create a list of all built DTB files 2024-02-19 18:20:39 +09:00
.mailmap mailmap: update email address for Satya Priya 2024-05-24 11:55:05 -07:00
.rustfmt.toml
COPYING
CREDITS MAINTAINERS: Drop Gustavo Pimentel as PCI DWC Maintainer 2024-03-27 13:41:02 -05:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS RTC for 6.10 2024-05-25 13:33:53 -07:00
Makefile Linux 6.10-rc1 2024-05-26 15:20:12 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.