All of lore.kernel.org
 help / color / mirror / Atom feed
* [syzbot] [fs?] KCSAN: data-race in inotify_handle_inode_event / inotify_remove_from_idr
@ 2023-04-24  8:09 syzbot
  2023-04-24  8:27 ` Dmitry Vyukov
  0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2023-04-24  8:09 UTC (permalink / raw)
  To: amir73il, jack, linux-fsdevel, linux-kernel, syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    622322f53c6d Merge tag 'mips-fixes_6.3_2' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1482ffafc80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fa4baf7c6b35b5d5
dashboard link: https://syzkaller.appspot.com/bug?extid=4a06d4373fd52f0b2f9c
compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8b5f31d96315/disk-622322f5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/adca7dc8daae/vmlinux-622322f5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ed78ddc31ccb/bzImage-622322f5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4a06d4373fd52f0b2f9c@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in inotify_handle_inode_event / inotify_remove_from_idr

write to 0xffff888104e31368 of 4 bytes by task 3229 on cpu 1:
 inotify_remove_from_idr+0x106/0x310 fs/notify/inotify/inotify_user.c:511
 inotify_ignored_and_remove_idr+0x34/0x60 fs/notify/inotify/inotify_user.c:532
 inotify_freeing_mark+0x1d/0x30 fs/notify/inotify/inotify_fsnotify.c:133
 fsnotify_free_mark fs/notify/mark.c:490 [inline]
 fsnotify_destroy_mark+0x17a/0x190 fs/notify/mark.c:499
 __do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:817 [inline]
 __se_sys_inotify_rm_watch+0xf7/0x170 fs/notify/inotify/inotify_user.c:794
 __x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:794
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888104e31368 of 4 bytes by task 3638 on cpu 0:
 inotify_handle_inode_event+0x17e/0x2c0 fs/notify/inotify/inotify_fsnotify.c:113
 fsnotify_handle_inode_event+0x19b/0x1f0 fs/notify/fsnotify.c:264
 fsnotify_handle_event fs/notify/fsnotify.c:316 [inline]
 send_to_group fs/notify/fsnotify.c:364 [inline]
 fsnotify+0x101c/0x1150 fs/notify/fsnotify.c:570
 __fsnotify_parent+0x307/0x480 fs/notify/fsnotify.c:230
 fsnotify_parent include/linux/fsnotify.h:77 [inline]
 fsnotify_file include/linux/fsnotify.h:99 [inline]
 fsnotify_close include/linux/fsnotify.h:341 [inline]
 __fput+0x4b0/0x570 fs/file_table.c:307
 ____fput+0x15/0x20 fs/file_table.c:349
 task_work_run+0x123/0x160 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd1/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000060 -> 0xffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3638 Comm: syz-executor.0 Not tainted 6.3.0-rc7-syzkaller-00191-g622322f53c6d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [syzbot] [fs?] KCSAN: data-race in inotify_handle_inode_event / inotify_remove_from_idr
  2023-04-24  8:09 [syzbot] [fs?] KCSAN: data-race in inotify_handle_inode_event / inotify_remove_from_idr syzbot
@ 2023-04-24  8:27 ` Dmitry Vyukov
  2023-04-24 13:54   ` Jan Kara
  0 siblings, 1 reply; 3+ messages in thread
From: Dmitry Vyukov @ 2023-04-24  8:27 UTC (permalink / raw)
  To: syzbot; +Cc: amir73il, jack, linux-fsdevel, linux-kernel, syzkaller-bugs

On Mon, 24 Apr 2023 at 10:09, syzbot
<syzbot+4a06d4373fd52f0b2f9c@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    622322f53c6d Merge tag 'mips-fixes_6.3_2' of git://git.ker..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1482ffafc80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=fa4baf7c6b35b5d5
> dashboard link: https://syzkaller.appspot.com/bug?extid=4a06d4373fd52f0b2f9c
> compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
>
> Unfortunately, I don't have any reproducer for this issue yet.
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/8b5f31d96315/disk-622322f5.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/adca7dc8daae/vmlinux-622322f5.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/ed78ddc31ccb/bzImage-622322f5.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+4a06d4373fd52f0b2f9c@syzkaller.appspotmail.com

If I am reading this correctly, userspace can get wd=-1 as the result
of this race. Docs say wd must refer to a previously allocated
descriptor, which is positive. I don't see any mentions of semantics
of wd=-1.

> ==================================================================
> BUG: KCSAN: data-race in inotify_handle_inode_event / inotify_remove_from_idr
>
> write to 0xffff888104e31368 of 4 bytes by task 3229 on cpu 1:
>  inotify_remove_from_idr+0x106/0x310 fs/notify/inotify/inotify_user.c:511
>  inotify_ignored_and_remove_idr+0x34/0x60 fs/notify/inotify/inotify_user.c:532
>  inotify_freeing_mark+0x1d/0x30 fs/notify/inotify/inotify_fsnotify.c:133
>  fsnotify_free_mark fs/notify/mark.c:490 [inline]
>  fsnotify_destroy_mark+0x17a/0x190 fs/notify/mark.c:499
>  __do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:817 [inline]
>  __se_sys_inotify_rm_watch+0xf7/0x170 fs/notify/inotify/inotify_user.c:794
>  __x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:794
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> read to 0xffff888104e31368 of 4 bytes by task 3638 on cpu 0:
>  inotify_handle_inode_event+0x17e/0x2c0 fs/notify/inotify/inotify_fsnotify.c:113
>  fsnotify_handle_inode_event+0x19b/0x1f0 fs/notify/fsnotify.c:264
>  fsnotify_handle_event fs/notify/fsnotify.c:316 [inline]
>  send_to_group fs/notify/fsnotify.c:364 [inline]
>  fsnotify+0x101c/0x1150 fs/notify/fsnotify.c:570
>  __fsnotify_parent+0x307/0x480 fs/notify/fsnotify.c:230
>  fsnotify_parent include/linux/fsnotify.h:77 [inline]
>  fsnotify_file include/linux/fsnotify.h:99 [inline]
>  fsnotify_close include/linux/fsnotify.h:341 [inline]
>  __fput+0x4b0/0x570 fs/file_table.c:307
>  ____fput+0x15/0x20 fs/file_table.c:349
>  task_work_run+0x123/0x160 kernel/task_work.c:179
>  resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
>  exit_to_user_mode_loop+0xd1/0xe0 kernel/entry/common.c:171
>  exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
>  __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
>  syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
>  do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> value changed: 0x00000060 -> 0xffffffff
>
> Reported by Kernel Concurrency Sanitizer on:
> CPU: 0 PID: 3638 Comm: syz-executor.0 Not tainted 6.3.0-rc7-syzkaller-00191-g622322f53c6d #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
> ==================================================================
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000c2e89505fa108749%40google.com.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [syzbot] [fs?] KCSAN: data-race in inotify_handle_inode_event / inotify_remove_from_idr
  2023-04-24  8:27 ` Dmitry Vyukov
@ 2023-04-24 13:54   ` Jan Kara
  0 siblings, 0 replies; 3+ messages in thread
From: Jan Kara @ 2023-04-24 13:54 UTC (permalink / raw)
  To: Dmitry Vyukov
  Cc: syzbot, amir73il, jack, linux-fsdevel, linux-kernel, syzkaller-bugs

On Mon 24-04-23 10:27:46, Dmitry Vyukov wrote:
> On Mon, 24 Apr 2023 at 10:09, syzbot
> <syzbot+4a06d4373fd52f0b2f9c@syzkaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    622322f53c6d Merge tag 'mips-fixes_6.3_2' of git://git.ker..
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=1482ffafc80000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=fa4baf7c6b35b5d5
> > dashboard link: https://syzkaller.appspot.com/bug?extid=4a06d4373fd52f0b2f9c
> > compiler:       Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
> >
> > Unfortunately, I don't have any reproducer for this issue yet.
> >
> > Downloadable assets:
> > disk image: https://storage.googleapis.com/syzbot-assets/8b5f31d96315/disk-622322f5.raw.xz
> > vmlinux: https://storage.googleapis.com/syzbot-assets/adca7dc8daae/vmlinux-622322f5.xz
> > kernel image: https://storage.googleapis.com/syzbot-assets/ed78ddc31ccb/bzImage-622322f5.xz
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+4a06d4373fd52f0b2f9c@syzkaller.appspotmail.com
> 
> If I am reading this correctly, userspace can get wd=-1 as the result
> of this race. Docs say wd must refer to a previously allocated
> descriptor, which is positive. I don't see any mentions of semantics
> of wd=-1.

Yeah, indeed this looks like a possible race when we detach the mark just
while we are generating the event. I'll send a fix.

								Honza

> > ==================================================================
> > BUG: KCSAN: data-race in inotify_handle_inode_event / inotify_remove_from_idr
> >
> > write to 0xffff888104e31368 of 4 bytes by task 3229 on cpu 1:
> >  inotify_remove_from_idr+0x106/0x310 fs/notify/inotify/inotify_user.c:511
> >  inotify_ignored_and_remove_idr+0x34/0x60 fs/notify/inotify/inotify_user.c:532
> >  inotify_freeing_mark+0x1d/0x30 fs/notify/inotify/inotify_fsnotify.c:133
> >  fsnotify_free_mark fs/notify/mark.c:490 [inline]
> >  fsnotify_destroy_mark+0x17a/0x190 fs/notify/mark.c:499
> >  __do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:817 [inline]
> >  __se_sys_inotify_rm_watch+0xf7/0x170 fs/notify/inotify/inotify_user.c:794
> >  __x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:794
> >  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> >  do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
> >  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >
> > read to 0xffff888104e31368 of 4 bytes by task 3638 on cpu 0:
> >  inotify_handle_inode_event+0x17e/0x2c0 fs/notify/inotify/inotify_fsnotify.c:113
> >  fsnotify_handle_inode_event+0x19b/0x1f0 fs/notify/fsnotify.c:264
> >  fsnotify_handle_event fs/notify/fsnotify.c:316 [inline]
> >  send_to_group fs/notify/fsnotify.c:364 [inline]
> >  fsnotify+0x101c/0x1150 fs/notify/fsnotify.c:570
> >  __fsnotify_parent+0x307/0x480 fs/notify/fsnotify.c:230
> >  fsnotify_parent include/linux/fsnotify.h:77 [inline]
> >  fsnotify_file include/linux/fsnotify.h:99 [inline]
> >  fsnotify_close include/linux/fsnotify.h:341 [inline]
> >  __fput+0x4b0/0x570 fs/file_table.c:307
> >  ____fput+0x15/0x20 fs/file_table.c:349
> >  task_work_run+0x123/0x160 kernel/task_work.c:179
> >  resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
> >  exit_to_user_mode_loop+0xd1/0xe0 kernel/entry/common.c:171
> >  exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
> >  __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
> >  syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
> >  do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
> >  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> >
> > value changed: 0x00000060 -> 0xffffffff
> >
> > Reported by Kernel Concurrency Sanitizer on:
> > CPU: 0 PID: 3638 Comm: syz-executor.0 Not tainted 6.3.0-rc7-syzkaller-00191-g622322f53c6d #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
> > ==================================================================
> >
> >
> > ---
> > This report is generated by a bot. It may contain errors.
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@googlegroups.com.
> >
> > syzbot will keep track of this issue. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >
> > --
> > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com.
> > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000c2e89505fa108749%40google.com.
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2023-04-24 13:56 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-04-24  8:09 [syzbot] [fs?] KCSAN: data-race in inotify_handle_inode_event / inotify_remove_from_idr syzbot
2023-04-24  8:27 ` Dmitry Vyukov
2023-04-24 13:54   ` Jan Kara

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.