Hello, When using fuzzer tool to fuzz the latest Linux kernel, the following crash was triggered. HEAD commit: 78d4f34e2115b517bcbfe7ec0d018bbbb6f9b0b8 git tree: upstream Console output: https://drive.google.com/file/d/1_GxT_B3JkCE8Q6r6PGgG27uNn5cgzZm3/view?usp=sharing Kernel config: https://drive.google.com/file/d/1RhT5dFTs6Vx1U71PbpenN7TPtnPoa3NI/view?usp=sharing C reproducer: https://drive.google.com/file/d/1zyZSM-hp1UInnE-AA9J3NXmMCV7DCqgf/view?usp=sharing Syzlang reproducer: https://drive.google.com/file/d/1W0yvbKYi6GaAaG0YNeDVacN3eEa8rxot/view?usp=sharing We are triggering the same issue and I hope this information is useful to you. If you fix this issue, please let me know. ================================================================== BUG: KASAN: slab-use-after-free in __mmap_complete mm/vma.c:2408 [inline] BUG: KASAN: slab-use-after-free in __mmap_region+0x22d6/0x2700 mm/vma.c:2469 Read of size 8 at addr ff110000085279c0 by task syz-executor339/448 CPU: 2 UID: 0 PID: 448 Comm: syz-executor339 Not tainted 6.13.0-rc3 #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1b0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcf/0x5f0 mm/kasan/report.c:489 kasan_report+0x93/0xc0 mm/kasan/report.c:602 __mmap_complete mm/vma.c:2408 [inline] __mmap_region+0x22d6/0x2700 mm/vma.c:2469 mmap_region+0x265/0x300 mm/mmap.c:1348 do_mmap+0xc3f/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1b3/0x380 mm/util.c:580 ksys_mmap_pgoff+0x477/0x600 mm/mmap.c:542 __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+0x127/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc3/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f53b07cbb1d Code: c3 e8 37 2a 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe3353bbe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00000000000172cc RCX: 00007f53b07cbb1d RDX: 0000000000000008 RSI: 0000000000001000 RDI: 0000000020ffe000 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 00007ffe3353bc04 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Allocated by task 448: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x87/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x154/0x420 mm/slub.c:4175 vm_area_alloc+0x20/0x200 kernel/fork.c:472 __mmap_new_vma mm/vma.c:2340 [inline] __mmap_region+0x1219/0x2700 mm/vma.c:2456 mmap_region+0x265/0x300 mm/mmap.c:1348 do_mmap+0xc3f/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1b3/0x380 mm/util.c:580 ksys_mmap_pgoff+0x477/0x600 mm/mmap.c:542 __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+0x127/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc3/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 425: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3a/0x60 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x54/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kmem_cache_free+0x126/0x4d0 mm/slub.c:4715 rcu_do_batch kernel/rcu/tree.c:2567 [inline] rcu_core+0x7cb/0x16c0 kernel/rcu/tree.c:2823 handle_softirqs+0x1ad/0x870 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu kernel/softirq.c:662 [inline] irq_exit_rcu+0xee/0x140 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x94/0xb0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 Last potentially related work creation: kasan_save_stack+0x24/0x50 mm/kasan/common.c:47 __kasan_record_aux_stack+0xa6/0xc0 mm/kasan/generic.c:544 __call_rcu_common.constprop.0+0x99/0x790 kernel/rcu/tree.c:3086 vma_complete+0x671/0xb70 mm/vma.c:310 commit_merge+0x7b3/0xec0 mm/vma.c:674 vma_merge_existing_range+0xd7a/0x1f10 mm/vma.c:897 __mmap_region+0x11e4/0x2700 mm/vma.c:2466 mmap_region+0x265/0x300 mm/mmap.c:1348 do_mmap+0xc3f/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1b3/0x380 mm/util.c:580 ksys_mmap_pgoff+0x477/0x600 mm/mmap.c:542 __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+0x127/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc3/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ff110000085279a0 which belongs to the cache vm_area_struct of size 160 The buggy address is located 32 bytes inside of freed 160-byte region [ff110000085279a0, ff11000008527a40) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8527 anon flags: 0x100000000000000(node=0|zone=1) page_type: f5(slab) raw: 0100000000000000 ff110000014cb680 ffd400000019bf40 dead00000000000d raw: 0000000000000000 0000000000120012 00000001f5000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ff11000008527880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ff11000008527900: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ff11000008527980: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb ^ ff11000008527a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ff11000008527a80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --------------- thanks, Kun Hu
