[syzbot] [kernel?] BUG: unable to handle kernel NULL pointer dereference in __hrtimer_run_queues

[syzbot <syzbot+558f67d44ad7f098a3de@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    4a4be1ad3a6e Revert "vfs: Delete the associated dentry whe..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1422a73c980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=bd6024aedb15e15c
dashboard link: https://syzkaller.appspot.com/bug?extid=558f67d44ad7f098a3de
compiler:       aarch64-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15583162980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12c1b514980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/384ffdcca292/non_bootable_disk-4a4be1ad.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/75957361122b/vmlinux-4a4be1ad.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6c766b0ec377/Image-4a4be1ad.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+558f67d44ad7f098a3de@syzkaller.appspotmail.com

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000090
Mem abort info:
  ESR = 0x0000000096000006
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x06: level 2 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 52-bit VAs, pgdp=000000004605bb80
[0000000000000090] pgd=08000000464ee003, p4d=08000000472aa003, pud=08000000471b8003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 3192 Comm: syz-executor607 Not tainted 6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0
Hardware name: linux,dummy-virt (DT)
pstate: 204000c9 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : rb_next+0x1c/0x54 lib/rbtree.c:505
lr : rb_erase_cached include/linux/rbtree.h:124 [inline]
lr : timerqueue_del+0x38/0x70 lib/timerqueue.c:57
sp : ffff800080003e70
x29: ffff800080003e70 x28: 0000000000000000 x27: fff000007f8cf780
x26: 0000000000000001 x25: 00000000000000c0 x24: 0000001f0198bc90
x23: fff000007f8cf780 x22: fff000007f8cf7e0 x21: fff000007f8cf780
x20: fff000007f8cf7e0 x19: ffff800088c3bd60 x18: 0000000000000000
x17: fff07ffffd319000 x16: ffff800080000000 x15: 0000ffffef309d38
x14: 00000000000003bb x13: 0000000000000000 x12: ffff8000825e0028
x11: 0000000000000001 x10: 0000000000000200 x9 : 0000000000200000
x8 : 0008000000000000 x7 : ff7ffffffffffbff x6 : 00000000019a23f5
x5 : fff07ffffd319000 x4 : 000000000a2dca90 x3 : ffff800088c3bd60
x2 : ff7000007f8cf8e8 x1 : 0000000000000080 x0 : 0000000000000080
Call trace:
 rb_next+0x1c/0x54 lib/rbtree.c:505
 __remove_hrtimer kernel/time/hrtimer.c:1118 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1667 [inline]
 __hrtimer_run_queues+0x104/0x1bc kernel/time/hrtimer.c:1751
 hrtimer_interrupt+0xe8/0x244 kernel/time/hrtimer.c:1813
 timer_handler drivers/clocksource/arm_arch_timer.c:674 [inline]
 arch_timer_handler_phys+0x2c/0x44 drivers/clocksource/arm_arch_timer.c:692
 handle_percpu_devid_irq+0x84/0x130 kernel/irq/chip.c:942
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq_desc kernel/irq/irqdesc.c:691 [inline]
 generic_handle_domain_irq+0x2c/0x44 kernel/irq/irqdesc.c:747
 gic_handle_irq+0x40/0xc4 drivers/irqchip/irq-gic.c:370
 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:889
 do_interrupt_handler+0x80/0x84 arch/arm64/kernel/entry-common.c:310
 __el1_irq arch/arm64/kernel/entry-common.c:536 [inline]
 el1_interrupt+0x34/0x64 arch/arm64/kernel/entry-common.c:551
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:556
 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:594
 __clear_young_dirty_ptes arch/arm64/include/asm/pgtable.h:1311 [inline]
 contpte_clear_young_dirty_ptes+0x68/0x128 arch/arm64/mm/contpte.c:389
 walk_pmd_range mm/pagewalk.c:143 [inline]
 walk_pud_range mm/pagewalk.c:221 [inline]
 walk_p4d_range mm/pagewalk.c:256 [inline]
 walk_pgd_range+0x4b0/0x8a4 mm/pagewalk.c:293
 __walk_page_range+0x178/0x180 mm/pagewalk.c:395
 walk_page_range+0x144/0x224 mm/pagewalk.c:521
 madvise_free_single_vma+0x134/0x2bc mm/madvise.c:815
 madvise_dontneed_free mm/madvise.c:929 [inline]
 madvise_vma_behavior+0x1d0/0x790 mm/madvise.c:1046
 madvise_walk_vmas+0xbc/0x12c mm/madvise.c:1268
 do_madvise+0x160/0x418 mm/madvise.c:1464
 __do_sys_madvise mm/madvise.c:1481 [inline]
 __se_sys_madvise mm/madvise.c:1479 [inline]
 __arm64_sys_madvise+0x24/0x34 mm/madvise.c:1479
 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
 invoke_syscall+0x48/0x118 arch/arm64/kernel/syscall.c:48
 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:133
 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:152
 el0_svc+0x34/0xf8 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:598
Code: 54000200 f9400401 b4000141 aa0103e0 (f9400821) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	54000200 	b.eq	0x40  // b.none
   4:	f9400401 	ldr	x1, [x0, #8]
   8:	b4000141 	cbz	x1, 0x30
   c:	aa0103e0 	mov	x0, x1
* 10:	f9400821 	ldr	x1, [x1, #16] <-- trapping instruction


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