================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x104/0x6800 kernel/locking/lockdep.c:4919 Read of size 8 at addr ffff0000dbe88bb0 by task gfs2_quotad/4566 CPU: 0 PID: 4566 Comm: gfs2_quotad Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec 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_load8_noabort+0x2c/0x38 mm/kasan/report_generic.c:351 __lock_acquire+0x104/0x6800 kernel/locking/lockdep.c:4919 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x6c/0xb0 kernel/locking/spinlock.c:162 finish_wait+0xc8/0x1ac kernel/sched/wait.c:410 gfs2_quotad+0x390/0x500 fs/gfs2/quota.c:1579 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Allocated by task 4860: 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] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node_track_caller+0xe0/0x16c mm/slab_common.c:956 kmemdup+0x5c/0x98 mm/util.c:129 kmemdup include/linux/fortify-string.h:585 [inline] ipv4_sysctl_init_net+0x58/0x238 net/ipv4/sysctl_net_ipv4.c:1410 ops_init+0x2b0/0x53c net/core/net_namespace.c:138 setup_net+0x474/0xb34 net/core/net_namespace.c:336 copy_net_ns+0x2b8/0x578 net/core/net_namespace.c:508 create_new_namespaces+0x318/0x5ec kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x108/0x158 kernel/nsproxy.c:226 ksys_unshare+0x3f8/0x6f4 kernel/fork.c:3282 __do_sys_unshare kernel/fork.c:3353 [inline] __se_sys_unshare kernel/fork.c:3351 [inline] __arm64_sys_unshare+0x3c/0x50 kernel/fork.c:3351 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 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 The buggy address belongs to the object at ffff0000dbe88000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 2992 bytes inside of 8192-byte region [ffff0000dbe88000, ffff0000dbe8a000) The buggy address belongs to the physical page: page:00000000af7cba47 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000dbe88000 pfn:0x11be88 head:00000000af7cba47 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 fffffc00032c6400 dead000000000004 ffff0000c0002c00 raw: ffff0000dbe88000 0000000080020000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000dbe88a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000dbe88b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000dbe88b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000dbe88c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000dbe88c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Unable to handle kernel paging request at virtual address dfff800000000017 KASAN: null-ptr-deref in range [0x00000000000000b8-0x00000000000000bf] 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 [dfff800000000017] address between user and kernel address ranges Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 4566 Comm: gfs2_quotad Tainted: G B syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 pstate: 824000c5 (Nzcv daIF +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : check_wait_context kernel/locking/lockdep.c:4723 [inline] pc : __lock_acquire+0x4c8/0x6800 kernel/locking/lockdep.c:4999 lr : hlock_class kernel/locking/lockdep.c:232 [inline] lr : check_wait_context kernel/locking/lockdep.c:4723 [inline] lr : __lock_acquire+0x6b8/0x6800 kernel/locking/lockdep.c:4999 sp : ffff800020c47940 x29: ffff800020c47b50 x28: dfff800000000000 x27: 0000000000000001 x26: ffff0000c972a638 x25: ffff0000c972a630 x24: dfff800000000000 x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000001d0e x20: ffff80001811bce0 x19: 00000000000000b8 x18: ffff800011b9bf60 x17: 0000000000000000 x16: ffff8000082eef80 x15: 0000000000000000 x14: 0000000000000001 x13: 1ffff00002fc1d6c x12: 0000000000ff0100 x11: ff0080000a872fa8 x10: ffff0000c972a658 x9 : ffff80000a872fa8 x8 : 0000000000000017 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800020c47318 x4 : ffff800015304cc0 x3 : ffff8000082dc634 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: check_wait_context kernel/locking/lockdep.c:4723 [inline] __lock_acquire+0x4c8/0x6800 kernel/locking/lockdep.c:4999 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x6c/0xb0 kernel/locking/spinlock.c:162 finish_wait+0xc8/0x1ac kernel/sched/wait.c:410 gfs2_quotad+0x390/0x500 fs/gfs2/quota.c:1579 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Code: 34000fe8 aa1f03e8 9102e113 d343fe68 (38fc6908) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 34000fe8 cbz w8, 0x1fc 4: aa1f03e8 mov x8, xzr 8: 9102e113 add x19, x8, #0xb8 c: d343fe68 lsr x8, x19, #3 * 10: 38fc6908 ldrsb w8, [x8, x28] <-- trapping instruction