md: recovery of RAID array md0 md: md0: recovery done. ================================================================== BUG: KASAN: use-after-free in r1buf_pool_free+0x130/0x134 drivers/md/raid1.c:228 Read of size 4 at addr ffff0000f2fe8f08 by task md0_resync/17812 CPU: 0 PID: 17812 Comm: md0_resync Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 __asan_report_load4_noabort+0x2c/0x38 mm/kasan/report_generic.c:350 r1buf_pool_free+0x130/0x134 drivers/md/raid1.c:228 mempool_exit+0x190/0x290 mm/mempool.c:174 close_sync drivers/md/raid1.c:1713 [inline] raid1_sync_request+0x328/0x26e4 drivers/md/raid1.c:2696 md_do_sync+0x2e18/0x36ec drivers/md/md.c:9158 md_thread+0x1e0/0x3cc drivers/md/md.c:8000 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Allocated by task 17755: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] kmalloc_trace+0x7c/0x94 mm/slab_common.c:1031 kmalloc include/linux/slab.h:563 [inline] raid1_reshape+0x590/0x102c drivers/md/raid1.c:3289 chunk_size_store+0x1ec/0x358 drivers/md/md.c:4290 md_attr_store+0x168/0x234 drivers/md/md.c:5626 sysfs_kf_write+0x1f8/0x274 fs/sysfs/file.c:140 kernfs_fop_write_iter+0x390/0x4b4 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x7c8 fs/read_write.c:584 ksys_write+0x12c/0x228 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Freed by task 17816: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] __kmem_cache_free+0xbc/0x21c mm/slub.c:3700 kfree+0xd0/0x1a8 mm/slab_common.c:988 raid1_reshape+0xc74/0x102c drivers/md/raid1.c:3332 chunk_size_store+0x1ec/0x358 drivers/md/md.c:4290 md_attr_store+0x168/0x234 drivers/md/md.c:5626 sysfs_kf_write+0x1f8/0x274 fs/sysfs/file.c:140 kernfs_fop_write_iter+0x390/0x4b4 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x7c8 fs/read_write.c:584 ksys_write+0x12c/0x228 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Last potentially related work creation: kasan_save_stack+0x40/0x70 mm/kasan/common.c:46 __kasan_record_aux_stack+0xc0/0xdc mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0x14/0x20 mm/kasan/generic.c:496 call_rcu+0x104/0x958 kernel/rcu/tree.c:2849 mpls_dev_notify+0x510/0x728 net/mpls/af_mpls.c:1659 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xd8/0x168 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2014 [inline] call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] unregister_netdevice_many_notify+0xf18/0x1900 net/core/dev.c:11023 unregister_netdevice_many net/core/dev.c:11077 [inline] default_device_exit_batch+0x9d4/0xa70 net/core/dev.c:11549 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x650/0xa90 net/core/net_namespace.c:640 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 The buggy address belongs to the object at ffff0000f2fe8f00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 8 bytes inside of 128-byte region [ffff0000f2fe8f00, ffff0000f2fe8f80) The buggy address belongs to the physical page: page:0000000069d0c5dd refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x132fe8 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 dead000000000100 dead000000000122 ffff0000c0002300 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f2fe8e00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ffff0000f2fe8e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000f2fe8f00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f2fe8f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000f2fe9000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Unable to handle kernel paging request at virtual address dfff800000000008 KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] 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 CM = 0, WnR = 0 [dfff800000000008] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 17812 Comm: md0_resync Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 pstate: 02400005 (nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : get_resync_pages drivers/md/raid1-10.c:90 [inline] pc : r1buf_pool_free+0x90/0x134 drivers/md/raid1.c:229 lr : r1buf_pool_free+0x84/0x134 drivers/md/raid1.c:229 sp : ffff800020b07500 x29: ffff800020b07500 x28: 1fffe0001e9ab84b x27: 1fffe0001e9ab84e x26: ffff80000ea38468 x25: 1fffe000198a88e2 x24: 0000000000004597 x23: ffff0000cc521a58 x22: dfff800000000000 x21: 0000000000000040 x20: ffff0000cc544710 x19: ffff0000cc521a00 x18: 1fffe00033e7277e x17: ffff80001537d000 x16: ffff800008043b30 x15: 0000000040000000 x14: 0000000000000001 x13: 1ffff00002ff016c x12: 0000000000000000 x11: ff0080000ea384c8 x10: 0000000000000000 x9 : ffff80001c5fab10 x8 : 0000000000000008 x7 : ffff800011cec160 x6 : ffff80000825ab50 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff80000ea384ec x2 : 0000000000000000 x1 : 0000000000000008 x0 : 0000000000000000 Call trace: get_resync_pages drivers/md/raid1-10.c:90 [inline] r1buf_pool_free+0x90/0x134 drivers/md/raid1.c:229 mempool_exit+0x190/0x290 mm/mempool.c:174 close_sync drivers/md/raid1.c:1713 [inline] raid1_sync_request+0x328/0x26e4 drivers/md/raid1.c:2696 md_do_sync+0x2e18/0x36ec drivers/md/md.c:9158 md_thread+0x1e0/0x3cc drivers/md/md.c:8000 kthread+0x254/0x2e0 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Code: 967af112 f9400288 91010115 d343fea8 (38766908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 967af112 bl 0xfffffffff9ebc448 4: f9400288 ldr x8, [x20] 8: 91010115 add x21, x8, #0x40 c: d343fea8 lsr x8, x21, #3 * 10: 38766908 ldrb w8, [x8, x22] <-- trapping instruction