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

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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    d76bb1ebb558 Merge tag 'erofs-for-6.15-rc6-fixes' of git:/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=155c58f4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=224acb8d2ffe8753
dashboard link: https://syzkaller.appspot.com/bug?extid=3ea73421f5aa3f339e9e
compiler:       aarch64-linux-gnu-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/fa3fbcfdac58/non_bootable_disk-d76bb1eb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cf604d463f46/vmlinux-d76bb1eb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/01922f2b5b5e/Image-d76bb1eb.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3ea73421f5aa3f339e9e@syzkaller.appspotmail.com

 el0t_64_sync_handler+0x10c/0x138 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:600
kobject: kobject_add_internal failed for raw_gadget with -EEXIST, don't try to register things with the same name in the same directory.
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
Mem abort info:
  ESR = 0x0000000096000046
  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 = 0x00000046, ISS2 = 0x00000000
  CM = 0, WnR = 1, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
user pgtable: 4k pages, 52-bit VAs, pgdp=00000000440f6980
[0000000000000008] pgd=0800000044a74403, p4d=080000004487c403, pud=0800000044880403, pmd=0000000000000000
Internal error: Oops: 0000000096000046 [#1]  SMP
Modules linked in:
CPU: 0 UID: 0 PID: 3469 Comm: syz.0.4 Not tainted 6.15.0-rc5-syzkaller-00043-gd76bb1ebb558 #0 PREEMPT 
Hardware name: linux,dummy-virt (DT)
pstate: 614020c9 (nZCv daIF +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : __lse__cmpxchg_case_acq_32 arch/arm64/include/asm/atomic_lse.h:271 [inline]
pc : __cmpxchg_case_acq_32 arch/arm64/include/asm/cmpxchg.h:120 [inline]
pc : __cmpxchg_acq arch/arm64/include/asm/cmpxchg.h:169 [inline]
pc : raw_atomic_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2055 [inline]
pc : raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2173 [inline]
pc : atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1302 [inline]
pc : queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
pc : do_raw_spin_lock include/linux/spinlock.h:187 [inline]
pc : __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
pc : _raw_spin_lock_irqsave+0x34/0x8c kernel/locking/spinlock.c:162
lr : complete_with_flags kernel/sched/completion.c:20 [inline]
lr : complete+0x24/0xa4 kernel/sched/completion.c:47
sp : ffff80008948bba0
x29: ffff80008948bba0 x28: fdf00000098d0000 x27: 0000000000000000
x26: 0000000000000000 x25: 0000000000000000 x24: f6f000000485c968
x23: ffff800081d77478 x22: 0000000000000000 x21: ffff80008256d388
x20: 0000000000000008 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: ffff800081b610e0
x14: 0000000000000164 x13: ffff8000828d1130 x12: 0000000000000001
x11: 000000ece58db54c x10: 7fd9d1af9fae5191 x9 : 6105f830acda155c
x8 : fdf00000098d11e8 x7 : fff000007f8d4b00 x6 : fff07ffffd022000
x5 : fff000007f8ca588 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000008
Call trace:
 __lse__cmpxchg_case_acq_32 arch/arm64/include/asm/atomic_lse.h:271 [inline] (P)
 __cmpxchg_case_acq_32 arch/arm64/include/asm/cmpxchg.h:120 [inline] (P)
 __cmpxchg_acq arch/arm64/include/asm/cmpxchg.h:169 [inline] (P)
 raw_atomic_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2055 [inline] (P)
 raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2173 [inline] (P)
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1302 [inline] (P)
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] (P)
 do_raw_spin_lock include/linux/spinlock.h:187 [inline] (P)
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] (P)
 _raw_spin_lock_irqsave+0x34/0x8c kernel/locking/spinlock.c:162 (P)
 complete_with_flags kernel/sched/completion.c:20 [inline]
 complete+0x24/0xa4 kernel/sched/completion.c:47
 module_kobj_release+0x14/0x20 kernel/params.c:946
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0xa4/0x114 lib/kobject.c:737
 lookup_or_create_module_kobject.part.0+0xac/0xdc kernel/params.c:783
 lookup_or_create_module_kobject+0x40/0x50 kernel/params.c:793
 module_add_driver+0xf0/0x16c drivers/base/module.c:46
 bus_add_driver+0xf8/0x208 drivers/base/bus.c:682
 driver_register+0x60/0x128 drivers/base/driver.c:249
 usb_gadget_register_driver_owner+0x54/0x13c drivers/usb/gadget/udc/core.c:1700
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:595 [inline]
 raw_ioctl+0x74c/0xd2c drivers/usb/gadget/legacy/raw_gadget.c:1306
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl fs/ioctl.c:892 [inline]
 __arm64_sys_ioctl+0xb4/0xe8 fs/ioctl.c:892
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x48/0x110 arch/arm64/kernel/syscall.c:49
 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151
 el0_svc+0xa0/0xe0 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x10c/0x138 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:600
Code: b9000841 d503201f 52800001 52800022 (88e17c02) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	b9000841 	str	w1, [x2, #8]
   4:	d503201f 	nop
   8:	52800001 	mov	w1, #0x0                   	// #0
   c:	52800022 	mov	w2, #0x1                   	// #1
* 10:	88e17c02 	casa	w1, w2, [x0] <-- trapping instruction


---
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#syz undup

Re: [syzbot] [io-uring?] [usb?] BUG: unable to handle kernel NULL pointer dereference in module_kobj_release

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    c32f8dc5aaf9 Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=13e8f4d4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ea4635ffd6ad5b4a
dashboard link: https://syzkaller.appspot.com/bug?extid=3ea73421f5aa3f339e9e
compiler:       Debian clang version 20.1.2 (++20250402124445+58df0ef89dd6-1~exp1~20250402004600.97), Debian LLD 20.1.2
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12ae5670580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b921498959d4/disk-c32f8dc5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/04e6ad946c4b/vmlinux-c32f8dc5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d4f0d8db50ee/Image-c32f8dc5.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3ea73421f5aa3f339e9e@syzkaller.appspotmail.com

 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
kobject: kobject_add_internal failed for raw_gadget with -EEXIST, don't try to register things with the same name in the same directory.
Unable to handle kernel paging request at virtual address dfff800000000004
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
Mem abort info:
  ESR = 0x0000000096000005
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x05: level 1 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfff800000000004] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1]  SMP
Modules linked in:
CPU: 1 UID: 0 PID: 6649 Comm: syz.0.16 Not tainted 6.15.0-rc5-syzkaller-gc32f8dc5aaf9 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
pstate: 204000c5 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kasan_byte_accessible+0x10/0x20 mm/kasan/generic.c:199
lr : __kasan_check_byte+0x20/0x54 mm/kasan/common.c:556
sp : ffff8000a37576d0
x29: ffff8000a37576d0 x28: ffff80008f311000 x27: ffff0000c7080000
x26: ffff80008add4a50 x25: 0000000000000000 x24: 0000000000000001
x23: 0000000000000000 x22: 0000000000000020 x21: 0000000000000020
x20: 0000000000000000 x19: ffff80008add4a50 x18: 1fffe0003386ce76
x17: 0000000000000000 x16: ffff80008adb410c x15: 0000000000000001
x14: 1fffe00018fbd927 x13: 0000000000000000 x12: 0000000000000000
x11: ffff600018fbd928 x10: 0000000000000003 x9 : dfff800000000000
x8 : 0000000000000004 x7 : 0000000000000001 x6 : ffff8000804f0148
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff80008add4a50 x0 : 0000000000000020
Call trace:
 kasan_mem_to_shadow include/linux/kasan.h:64 [inline] (P)
 kasan_byte_accessible+0x10/0x20 mm/kasan/generic.c:199 (P)
 kasan_check_byte include/linux/kasan.h:399 [inline]
 lock_acquire+0xb0/0x2e0 kernel/locking/lockdep.c:5840
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162
 complete_with_flags kernel/sched/completion.c:20 [inline]
 complete+0x30/0x1a0 kernel/sched/completion.c:47
 module_kobj_release+0x40/0x50 kernel/params.c:946
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x2b0/0x438 lib/kobject.c:737
 lookup_or_create_module_kobject+0x150/0x16c kernel/params.c:783
 module_add_driver+0xb8/0x2dc drivers/base/module.c:46
 bus_add_driver+0x328/0x5b0 drivers/base/bus.c:682
 driver_register+0x220/0x30c drivers/base/driver.c:249
 usb_gadget_register_driver_owner+0xe4/0x250 drivers/usb/gadget/udc/core.c:1700
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:595 [inline]
 raw_ioctl+0xfc4/0x33e8 drivers/usb/gadget/legacy/raw_gadget.c:1306
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl fs/ioctl.c:892 [inline]
 __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:892
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
Code: d503245f d343fc08 d2d00009 f2fbffe9 (38696908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	d503245f 	bti	c
   4:	d343fc08 	lsr	x8, x0, #3
   8:	d2d00009 	mov	x9, #0x800000000000        	// #140737488355328
   c:	f2fbffe9 	movk	x9, #0xdfff, lsl #48
* 10:	38696908 	ldrb	w8, [x8, x9] <-- trapping instruction


---
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Re: [syzbot] [io-uring?] [usb?] BUG: unable to handle kernel NULL pointer dereference in module_kobj_release

[Jens Axboe]

#syz set subsystems: usb

-- 
Jens Axboe