Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot <syzbot+3a36aeabd31497d63f6e@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in block_invalidate_folio

INFO: task kworker/3:1H:1222 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/3:1H    state:D stack:26784 pid:1222  tgid:1222  ppid:2      flags:0x00004000
Workqueue: glock_workqueue glock_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6838
 io_schedule+0xbf/0x130 kernel/sched/core.c:9044
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0x112/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0xda/0x110 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer fs/buffer.c:71 [inline]
 lock_buffer include/linux/buffer_head.h:401 [inline]
 discard_buffer fs/buffer.c:1565 [inline]
 block_invalidate_folio+0x54d/0x5e0 fs/buffer.c:1622
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x2ac/0x3e0 mm/truncate.c:178
 truncate_inode_pages_range+0x271/0xe90 mm/truncate.c:358
 rgrp_go_inval+0x15b/0x1c0 fs/gfs2/glops.c:236
 do_xmote+0x7ca/0xe00 fs/gfs2/glock.c:750
 run_queue+0x2fb/0x650 fs/gfs2/glock.c:861
 glock_work_func+0x103/0x390 fs/gfs2/glock.c:1093
 process_one_work+0x9a9/0x1ac0 kernel/workqueue.c:3254
 process_scheduled_works kernel/workqueue.c:3335 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor.0:5432 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:23168 pid:5432  tgid:5432  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6838
 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2558
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x3de/0x5f0 kernel/sched/completion.c:116
 __flush_work+0x5c4/0xb10 kernel/workqueue.c:4205
 gfs2_clear_rgrpd+0x28d/0x330 fs/gfs2/rgrp.c:731
 gfs2_put_super+0x4a6/0x760 fs/gfs2/super.c:643
 generic_shutdown_super+0x159/0x3d0 fs/super.c:641
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a83e7f197
RSP: 002b:00007ffc270ab458 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f6a83e7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc270ab510
RBP: 00007ffc270ab510 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc270ac5d0
R13: 00007f6a83ec93b9 R14: 0000000000012eb3 R15: 0000000000000001
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/39:
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614
2 locks held by kworker/3:1H/1222:
 #0: ffff88801bf74148 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_one_work+0x1296/0x1ac0 kernel/workqueue.c:3229
 #1: ffffc9000956fd80 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1ac0 kernel/workqueue.c:3230
2 locks held by getty/4998:
 #0: ffff8880162d60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000009b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201
1 lock held by syz-executor.0/5432:
 #0: ffff88801fc3c0e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88801fc3c0e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88801fc3c0e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:504

=============================================

NMI backtrace for cpu 2
CPU: 2 PID: 39 Comm: khungtaskd Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xf86/0x1240 kernel/hung_task.c:380
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 2 to CPUs 0-1,3:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:742
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:742
NMI backtrace for cpu 3 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 3 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 3 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:742


Tested on:

commit:         e8c39d0f Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=173e4c93180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12b101eb180000