================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] BUG: KASAN: slab-use-after-free in membarrier_switch_mm kernel/sched/sched.h:3670 [inline] BUG: KASAN: slab-use-after-free in context_switch kernel/sched/core.c:5230 [inline] BUG: KASAN: slab-use-after-free in __schedule+0xc56/0x5fa0 kernel/sched/core.c:6867 Read of size 4 at addr ffff8880323c0d00 by task syz.0.17/5997 CPU: 1 UID: 0 PID: 5997 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] membarrier_switch_mm kernel/sched/sched.h:3670 [inline] context_switch kernel/sched/core.c:5230 [inline] __schedule+0xc56/0x5fa0 kernel/sched/core.c:6867 do_task_dead+0xca/0x100 kernel/sched/core.c:6888 do_exit+0x1677/0x2a30 kernel/exit.c:1014 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1121 x64_sys_call+0x14fd/0x1510 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcab0b9bf79 Code: Unable to access opcode bytes at 0x7fcab0b9bf4f. RSP: 002b:00007ffd4b156288 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcab0b9bf79 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 0000000000000000 R09: 00007fcab0de4280 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcab0de4280 R14: 0000000000000003 R15: 00007ffd4b156340 Allocated by task 5934: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x2ad/0x780 mm/slub.c:5270 dup_mm kernel/fork.c:1520 [inline] copy_mm kernel/fork.c:1582 [inline] copy_process+0x72ff/0x79b0 kernel/fork.c:2223 kernel_clone+0xfc/0x930 kernel/fork.c:2654 __do_sys_clone+0xd9/0x120 kernel/fork.c:2795 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5997: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6674 [inline] kmem_cache_free+0x143/0x720 mm/slub.c:6789 mmdrop include/linux/sched/mm.h:55 [inline] __mmput+0x379/0x410 kernel/fork.c:1186 mmput+0x67/0x80 kernel/fork.c:1197 exit_mm kernel/exit.c:581 [inline] do_exit+0x78a/0x2a30 kernel/exit.c:959 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1121 x64_sys_call+0x14fd/0x1510 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880323c0c40 which belongs to the cache mm_struct of size 2968 The buggy address is located 192 bytes inside of freed 2968-byte region [ffff8880323c0c40, ffff8880323c17d8) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x323c0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888033e87501 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fe30b40 ffffea0000c5da00 0000000000000005 raw: 0000000000000000 00000000800a000a 00000000f5000000 ffff888033e87501 head: 00fff00000000040 ffff88813fe30b40 ffffea0000c5da00 0000000000000005 head: 0000000000000000 00000000800a000a 00000000f5000000 ffff888033e87501 head: 00fff00000000003 ffffea0000c8f001 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5486, tgid 5486 (dhcpcd), ts 78293233507, free_ts 78166019155 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0xe3d/0x2e10 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5240 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c4/0x440 mm/slub.c:3302 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] kmem_cache_alloc_noprof+0x4ec/0x780 mm/slub.c:5270 dup_mm kernel/fork.c:1520 [inline] copy_mm kernel/fork.c:1582 [inline] copy_process+0x72ff/0x79b0 kernel/fork.c:2223 kernel_clone+0xfc/0x930 kernel/fork.c:2654 __do_sys_clone+0xd9/0x120 kernel/fork.c:2795 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5655 tgid 5655 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x822/0x1130 mm/page_alloc.c:2973 discard_slab mm/slub.c:3346 [inline] __put_partials+0x127/0x160 mm/slub.c:3886 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x2ad/0x780 mm/slub.c:5270 vm_area_dup+0x27/0x8e0 mm/vma_init.c:123 __split_vma+0x18c/0xe30 mm/vma.c:513 vms_gather_munmap_vmas+0x3aa/0x1320 mm/vma.c:1423 __mmap_setup mm/vma.c:2405 [inline] __mmap_region+0x46e/0x2820 mm/vma.c:2734 mmap_region+0x180/0x3e0 mm/vma.c:2830 do_mmap+0xc63/0x12f0 mm/mmap.c:558 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581 ksys_mmap_pgoff+0x328/0x5b0 mm/mmap.c:604 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff8880323c0c00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff8880323c0c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880323c0d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880323c0d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880323c0e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================