================================================================== BUG: KASAN: slab-use-after-free in software_node_notify_remove+0x1c4/0x1c8 drivers/base/swnode.c:1108 Read of size 1 at addr ffff0000c9049d08 by task syz.0.168/7622 CPU: 1 UID: 0 PID: 7622 Comm: syz.0.168 Not tainted 6.15.0-rc2-syzkaller-gc72692105976 #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xa8/0x254 mm/kasan/report.c:408 print_report+0x68/0x84 mm/kasan/report.c:521 kasan_report+0xb0/0x110 mm/kasan/report.c:634 __asan_report_load1_noabort+0x20/0x2c mm/kasan/report_generic.c:378 software_node_notify_remove+0x1c4/0x1c8 drivers/base/swnode.c:1108 device_platform_notify_remove drivers/base/core.c:2387 [inline] device_del+0x494/0x808 drivers/base/core.c:3858 device_unregister+0x2c/0xcc drivers/base/core.c:3896 mock_dev_destroy drivers/iommu/iommufd/selftest.c:960 [inline] iommufd_selftest_destroy+0xc0/0xe0 drivers/iommu/iommufd/selftest.c:1850 iommufd_fops_release+0x13c/0x2cc drivers/iommu/iommufd/main.c:261 __fput+0x340/0x75c fs/file_table.c:465 ____fput+0x20/0x58 fs/file_table.c:493 task_work_run+0x1dc/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] do_notify_resume+0x178/0x1f8 arch/arm64/kernel/entry-common.c:151 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xb0/0x150 arch/arm64/kernel/entry-common.c:745 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Allocated by task 7623: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:562 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x2a4/0x3fc mm/slub.c:4362 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] swnode_register+0x70/0x490 drivers/base/swnode.c:790 fwnode_create_software_node+0x188/0x1e0 drivers/base/swnode.c:949 device_create_managed_software_node+0xe0/0x1fc drivers/base/swnode.c:1060 mock_dev_create drivers/iommu/iommufd/selftest.c:942 [inline] iommufd_test_mock_domain drivers/iommu/iommufd/selftest.c:989 [inline] iommufd_test+0x2450/0x4c44 drivers/iommu/iommufd/selftest.c:1866 iommufd_fops_ioctl+0x420/0x4fc drivers/iommu/iommufd/main.c:419 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+0x58/0x150 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Freed by task 7622: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x68/0x88 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free mm/slub.c:4646 [inline] kfree+0x17c/0x474 mm/slub.c:4845 software_node_release+0x1cc/0x238 drivers/base/swnode.c:775 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 software_node_notify_remove+0x168/0x1c8 drivers/base/swnode.c:1106 device_platform_notify_remove drivers/base/core.c:2387 [inline] device_del+0x494/0x808 drivers/base/core.c:3858 device_unregister+0x2c/0xcc drivers/base/core.c:3896 mock_dev_destroy drivers/iommu/iommufd/selftest.c:960 [inline] iommufd_selftest_destroy+0xc0/0xe0 drivers/iommu/iommufd/selftest.c:1850 iommufd_fops_release+0x13c/0x2cc drivers/iommu/iommufd/main.c:261 __fput+0x340/0x75c fs/file_table.c:465 ____fput+0x20/0x58 fs/file_table.c:493 task_work_run+0x1dc/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] do_notify_resume+0x178/0x1f8 arch/arm64/kernel/entry-common.c:151 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xb0/0x150 arch/arm64/kernel/entry-common.c:745 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 The buggy address belongs to the object at ffff0000c9049c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of freed 512-byte region [ffff0000c9049c00, ffff0000c9049e00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109048 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c0001c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c0001c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 05ffc00000000002 fffffdffc3241201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000c9049c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c9049c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000c9049d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000c9049d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c9049e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 7622 at lib/refcount.c:28 refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 Modules linked in: CPU: 1 UID: 0 PID: 7622 Comm: syz.0.168 Tainted: G B 6.15.0-rc2-syzkaller-gc72692105976 #0 PREEMPT Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 lr : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 sp : ffff8000a3b37970 x29: ffff8000a3b37970 x28: dfff800000000000 x27: 1fffe00019209380 x26: 1fffe00019209387 x25: dfff800000000000 x24: 0000000000000000 x23: dfff800000000000 x22: ffff0000c9049c3c x21: 0000000000000000 x20: ffff0000c9049c38 x19: ffff8000927e3000 x18: 1fffe000367122b6 x17: 0000000000000000 x16: ffff80008ad04488 x15: ffff700011e6bf2c x14: 1ffff00011e6bf2c x13: 0000000000000004 x12: ffffffffffffffff x11: ffff700011e6bf2c x10: 0000000000ff0100 x9 : ab1fcdd8ae1d5d00 x8 : ab1fcdd8ae1d5d00 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff8000a3b372b8 x4 : ffff80008f3d4f00 x3 : ffff80008054049c x2 : 0000000000000000 x1 : 0000000100000000 x0 : 0000000000000000 Call trace: refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 (P) __refcount_sub_and_test include/linux/refcount.h:400 [inline] __refcount_dec_and_test include/linux/refcount.h:432 [inline] refcount_dec_and_test include/linux/refcount.h:450 [inline] kref_put include/linux/kref.h:64 [inline] kobject_put+0x194/0x438 lib/kobject.c:737 software_node_notify_remove+0x1ac/0x1c8 drivers/base/swnode.c:1110 device_platform_notify_remove drivers/base/core.c:2387 [inline] device_del+0x494/0x808 drivers/base/core.c:3858 device_unregister+0x2c/0xcc drivers/base/core.c:3896 mock_dev_destroy drivers/iommu/iommufd/selftest.c:960 [inline] iommufd_selftest_destroy+0xc0/0xe0 drivers/iommu/iommufd/selftest.c:1850 iommufd_fops_release+0x13c/0x2cc drivers/iommu/iommufd/main.c:261 __fput+0x340/0x75c fs/file_table.c:465 ____fput+0x20/0x58 fs/file_table.c:493 task_work_run+0x1dc/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] do_notify_resume+0x178/0x1f8 arch/arm64/kernel/entry-common.c:151 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xb0/0x150 arch/arm64/kernel/entry-common.c:745 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 irq event stamp: 2649 hardirqs last enabled at (2649): [] raw_spin_rq_unlock_irq kernel/sched/sched.h:1525 [inline] hardirqs last enabled at (2649): [] finish_lock_switch+0xb0/0x1c0 kernel/sched/core.c:5130 hardirqs last disabled at (2648): [] __schedule+0x318/0x28d4 kernel/sched/core.c:6671 softirqs last enabled at (2230): [] softirq_handle_end kernel/softirq.c:425 [inline] softirqs last enabled at (2230): [] handle_softirqs+0xaf8/0xc88 kernel/softirq.c:607 softirqs last disabled at (2203): [] __do_softirq+0x14/0x20 kernel/softirq.c:613 ---[ end trace 0000000000000000 ]---