================================================================== BUG: KASAN: slab-use-after-free in blk_log_remap+0xa8/0x120 kernel/trace/blktrace.c:1635 Read of size 8 at addr ffff88807f80a000 by task syz.0.4463/22856 CPU: 0 UID: 0 PID: 22856 Comm: syz.0.4463 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 blk_log_remap+0xa8/0x120 kernel/trace/blktrace.c:1635 print_one_line+0x29d/0x300 kernel/trace/blktrace.c:1757 tracing_read_pipe+0x568/0xb50 kernel/trace/trace.c:5446 vfs_read+0x213/0xa80 fs/read_write.c:572 ksys_read+0x150/0x270 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb6f499e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb6f588e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fb6f4c26180 RCX: 00007fb6f499e0d9 RDX: 0000000000004000 RSI: 0000200000004580 RDI: 000000000000000a RBP: 00007fb6f4a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb6f4c26218 R14: 00007fb6f4c26180 R15: 00007ffe607afca8 Allocated by task 22665: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x331/0x660 mm/slub.c:5484 _kmalloc_noprof include/linux/slab.h:988 [inline] slab_free_hook mm/slub.c:2630 [inline] slab_free mm/slub.c:6372 [inline] kmem_cache_free+0x156/0x650 mm/slub.c:6499 anon_vma_free mm/rmap.c:137 [inline] __put_anon_vma+0x12b/0x2d0 mm/rmap.c:2964 put_anon_vma mm/internal.h:293 [inline] unlink_anon_vmas+0x544/0x720 mm/rmap.c:536 free_pgtables+0x836/0xb70 mm/memory.c:414 exit_mmap+0x4aa/0x9f0 mm/mmap.c:1327 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x221/0x2d0 kernel/exit.c:614 do_exit+0x6cd/0x2360 kernel/exit.c:996 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 __do_sys_exit_group kernel/exit.c:1162 [inline] __se_sys_exit_group kernel/exit.c:1160 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1160 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 22660: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2678 [inline] slab_free mm/slub.c:6372 [inline] kfree+0x1c5/0x640 mm/slub.c:6687 slab_free_after_rcu_debug+0x62/0x220 mm/slub.c:6421 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x794/0x10b0 kernel/rcu/tree.c:2897 handle_softirqs+0x226/0x860 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:767 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x57/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3159 [inline] call_rcu+0xee/0x8b0 kernel/rcu/tree.c:3279 slab_free_hook mm/slub.c:2642 [inline] slab_free mm/slub.c:6372 [inline] kmem_cache_free+0x466/0x650 mm/slub.c:6499 anon_vma_free mm/rmap.c:137 [inline] __put_anon_vma+0x12b/0x2d0 mm/rmap.c:2964 put_anon_vma mm/internal.h:293 [inline] unlink_anon_vmas+0x544/0x720 mm/rmap.c:536 free_pgtables+0x836/0xb70 mm/memory.c:414 exit_mmap+0x4aa/0x9f0 mm/mmap.c:1327 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x221/0x2d0 kernel/exit.c:614 do_exit+0x6cd/0x2360 kernel/exit.c:996 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 __do_sys_exit_group kernel/exit.c:1162 [inline] __se_sys_exit_group kernel/exit.c:1160 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1160 x64_sys_call+0x18c6/0x18d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807f80a000 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of freed 32-byte region [ffff88807f80a000, ffff88807f80a020) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807f80a980 pfn:0x7f80a flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000200 ffff88801b041780 ffffea0000cd85d0 ffffea0001ed91d0 raw: ffff88807f80a980 0000000800400015 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7051, tgid 7051 (modprobe), ts 220249870321 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x2209/0x2280 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x217/0x5a0 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3267 [inline] allocate_slab+0x7c/0x5e0 mm/slub.c:3382 new_slab mm/slub.c:3428 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7305 refill_sheaf mm/slub.c:2805 [inline] __pcs_replace_empty_main+0x2c3/0x6b0 mm/slub.c:4677 alloc_from_pcs mm/slub.c:4775 [inline] slab_alloc_node mm/slub.c:4907 [inline] __kmalloc_cache_noprof+0x3ab/0x660 mm/slub.c:5480 _kmalloc_noprof include/linux/slab.h:988 [inline] slab_free_hook mm/slub.c:2630 [inline] slab_free mm/slub.c:6372 [inline] kmem_cache_free+0x156/0x650 mm/slub.c:6499 anon_vma_free mm/rmap.c:137 [inline] __put_anon_vma+0x12b/0x2d0 mm/rmap.c:2964 put_anon_vma mm/internal.h:293 [inline] unlink_anon_vmas+0x544/0x720 mm/rmap.c:536 free_pgtables+0x836/0xb70 mm/memory.c:414 exit_mmap+0x4aa/0x9f0 mm/mmap.c:1327 __mmput+0x118/0x420 kernel/fork.c:1193 exit_mm+0x221/0x2d0 kernel/exit.c:614 do_exit+0x6cd/0x2360 kernel/exit.c:996 do_group_exit+0x22d/0x2f0 kernel/exit.c:1151 page last free pid 4972 tgid 4972 ts 220248750708 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962 __slab_free+0x274/0x2c0 mm/slub.c:5736 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4586 [inline] slab_alloc_node mm/slub.c:4919 [inline] kmem_cache_alloc_noprof+0x2a4/0x5f0 mm/slub.c:4933 alloc_filename fs/namei.c:147 [inline] do_getname+0x2e/0x250 fs/namei.c:187 class_filename_flags_constructor include/linux/fs.h:2587 [inline] do_readlinkat+0xc8/0x510 fs/stat.c:569 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88807f809f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88807f809f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88807f80a000: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88807f80a080: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88807f80a100: 00 00 02 fc fc fc fc fc 00 00 00 00 fc fc fc fc ==================================================================