================================================================== BUG: KASAN: out-of-bounds in instrument_atomic_read_write include/linux/instrumented.h:96 [inline] BUG: KASAN: out-of-bounds in atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline] BUG: KASAN: out-of-bounds in put_bh include/linux/buffer_head.h:304 [inline] BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161 Write of size 4 at addr ffffc90004597720 by task swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc6-syzkaller-00346-g5723cc3450bc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xb4/0x290 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x29a/0x2b0 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline] put_bh include/linux/buffer_head.h:304 [inline] end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161 end_bio_bh_io_sync+0xbd/0x120 fs/buffer.c:2781 blk_update_request+0x5ee/0xe80 block/blk-mq.c:983 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1145 blk_complete_reqs block/blk-mq.c:1220 [inline] blk_done_softirq+0x10a/0x160 block/blk-mq.c:1225 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline] sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:266 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5250 Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 e9 27 05 00 00 4c 8b 75 d0 4c 89 e7 e8 8f 00 c7 09 e8 6a 66 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffffff8dc07af8 EFLAGS: 00000282 RAX: 07b4e63825b26d00 RBX: 0000000000000000 RCX: 07b4e63825b26d00 RDX: 0000000000000000 RSI: ffffffff8d74e0ce RDI: ffffffff8bc1f3c0 RBP: ffffffff8dc07b50 R08: ffffffff8f7f3377 R09: 1ffffffff1efe66e R10: dffffc0000000000 R11: fffffbfff1efe66f R12: ffffffff8dc95240 R13: dffffc0000000000 R14: ffff888030f89e00 R15: ffff8880b883a6d8 context_switch kernel/sched/core.c:5385 [inline] __schedule+0x16ea/0x4cd0 kernel/sched/core.c:6767 schedule_idle+0x52/0x90 kernel/sched/core.c:6886 do_idle+0x4ad/0x510 kernel/sched/idle.c:353 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:743 start_kernel+0x470/0x4f0 init/main.c:1099 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494 common_startup_64+0x13e/0x147 The buggy address belongs to the virtual mapping at [ffffc90004590000, ffffc90004599000) created by: copy_process+0x544/0x3b80 kernel/fork.c:2260 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805ac46000 pfn:0x5ac40 memcg:ffff888029838702 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000 raw: ffff88805ac46000 0000000000000000 00000001ffffffff ffff888029838702 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), pid 9220, tgid 9220 (syz.5.814), ts 372145977689, free_ts 371254911656 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1714 prep_new_page mm/page_alloc.c:1722 [inline] get_page_from_freelist+0x21ce/0x22b0 mm/page_alloc.c:3684 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4966 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2392 vm_area_alloc_pages mm/vmalloc.c:3592 [inline] __vmalloc_area_node mm/vmalloc.c:3670 [inline] __vmalloc_node_range_noprof+0x8fe/0x12c0 mm/vmalloc.c:3845 __vmalloc_node_noprof+0x7d/0x90 mm/vmalloc.c:3908 alloc_thread_stack_node kernel/fork.c:314 [inline] dup_task_struct+0x3e7/0x860 kernel/fork.c:1137 copy_process+0x544/0x3b80 kernel/fork.c:2260 kernel_clone+0x21e/0x870 kernel/fork.c:2845 __do_sys_clone3 kernel/fork.c:3149 [inline] __se_sys_clone3+0x256/0x2d0 kernel/fork.c:3128 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5888 tgid 5888 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1258 [inline] __free_frozen_pages+0xb0e/0xcd0 mm/page_alloc.c:2721 discard_slab mm/slub.c:2716 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3185 put_cpu_partial+0x17c/0x250 mm/slub.c:3260 __slab_free+0x2f7/0x400 mm/slub.c:4512 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203 anon_vma_chain_alloc mm/rmap.c:142 [inline] __anon_vma_prepare+0xcb/0x4a0 mm/rmap.c:195 __vmf_anon_prepare mm/memory.c:3432 [inline] vmf_anon_prepare mm/internal.h:410 [inline] do_anonymous_page mm/memory.c:4996 [inline] do_pte_missing mm/memory.c:4158 [inline] handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x4b7d/0x5380 mm/memory.c:6140 handle_mm_fault+0x3f6/0x8c0 mm/memory.c:6309 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 Memory state around the buggy address: ffffc90004597600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffffc90004597680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc90004597700: f1 f1 f1 f1 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 ^ ffffc90004597780: 00 f2 f2 f2 01 f3 f3 f3 00 00 00 00 00 00 00 00 ffffc90004597800: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f3 f3 f3 ================================================================== ---------------- Code disassembly (best guess): 0: 0f 84 3c 01 00 00 je 0x142 6: 48 85 db test %rbx,%rbx 9: 0f 85 63 01 00 00 jne 0x172 f: e9 27 05 00 00 jmp 0x53b 14: 4c 8b 75 d0 mov -0x30(%rbp),%r14 18: 4c 89 e7 mov %r12,%rdi 1b: e8 8f 00 c7 09 call 0x9c700af 20: e8 6a 66 35 00 call 0x35668f 25: fb sti 26: 4c 8b 65 c0 mov -0x40(%rbp),%r12 * 2a: 49 8d bc 24 18 16 00 lea 0x1618(%r12),%rdi <-- trapping instruction 31: 00 32: 48 89 f8 mov %rdi,%rax 35: 48 c1 e8 03 shr $0x3,%rax 39: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax 3e: 84 c0 test %al,%al