================================================================== 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:3721 [inline] BUG: KASAN: slab-use-after-free in context_switch kernel/sched/core.c:5265 [inline] BUG: KASAN: slab-use-after-free in __schedule+0xc8d/0x6000 kernel/sched/core.c:6907 Read of size 4 at addr ffff88813fe42580 by task syz-executor/5821 CPU: 0 UID: 0 PID: 5821 Comm: syz-executor 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:3721 [inline] context_switch kernel/sched/core.c:5265 [inline] __schedule+0xc8d/0x6000 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7004 do_nanosleep+0x206/0x560 kernel/time/hrtimer.c:2124 hrtimer_nanosleep+0x156/0x360 kernel/time/hrtimer.c:2171 common_nsleep+0xa1/0xd0 kernel/time/posix-timers.c:1345 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1391 [inline] __se_sys_clock_nanosleep kernel/time/posix-timers.c:1368 [inline] __x64_sys_clock_nanosleep+0x336/0x480 kernel/time/posix-timers.c:1368 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff133b5c84e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffd8645e248 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00005555867d6500 RCX: 00007ff133b5c84e RDX: 00007ffd8645e2a0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd8645e30c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388 R13: 00000000000927c0 R14: 000000000002227a R15: 00007ffd8645e360 Allocated by task 5818: 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:4459 [inline] slab_alloc_node mm/slub.c:4788 [inline] kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4795 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+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6738: 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:2670 [inline] slab_free mm/slub.c:6082 [inline] kmem_cache_free+0x124/0x670 mm/slub.c:6212 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 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034 arch_do_signal_or_restart+0x91/0x770 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x668/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88813fe424c0 which belongs to the cache mm_struct of size 2968 The buggy address is located 192 bytes inside of freed 2968-byte region [ffff88813fe424c0, ffff88813fe43058) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13fe40 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888029524181 flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 017ff00000000040 ffff88813fe09b40 dead000000000100 dead000000000122 raw: 0000000000000000 00000008000a000a 00000000f5000000 ffff888029524181 head: 017ff00000000040 ffff88813fe09b40 dead000000000100 dead000000000122 head: 0000000000000000 00000008000a000a 00000000f5000000 ffff888029524181 head: 017ff00000000003 ffffea0004ff9001 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 0xd2000(__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 0, tgid 0 (swapper), ts 1552151021, free_ts 0 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+0x111d/0x3140 mm/page_alloc.c:3950 __alloc_frozen_pages_noprof+0x26c/0x2410 mm/page_alloc.c:5245 alloc_slab_page mm/slub.c:3238 [inline] allocate_slab mm/slub.c:3411 [inline] new_slab+0xa6/0x6e0 mm/slub.c:3469 refill_objects+0x26b/0x400 mm/slub.c:7091 refill_sheaf mm/slub.c:2787 [inline] alloc_full_sheaf mm/slub.c:2808 [inline] __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4546 alloc_from_pcs mm/slub.c:4639 [inline] slab_alloc_node mm/slub.c:4773 [inline] kmem_cache_alloc_noprof+0x480/0x6e0 mm/slub.c:4795 mm_alloc+0x1c/0xd0 kernel/fork.c:1157 poking_init+0x6b/0x2f0 arch/x86/mm/init.c:824 start_kernel+0x1bf/0x480 init/main.c:1068 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x122/0x130 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 page_owner free stack trace missing Memory state around the buggy address: ffff88813fe42480: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88813fe42500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88813fe42580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88813fe42600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88813fe42680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================