Hello, syzbot found the following issue on: HEAD commit: a5618886fdab Merge remote-tracking branch 'will/for-next/p.. git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=15f8c474580000 kernel config: https://syzkaller.appspot.com/x/.config?x=29061e148cfaa3d3 dashboard link: https://syzkaller.appspot.com/bug?extid=856397091bcfa77c8175 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: arm64 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/8b90307e7f61/disk-a5618886.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8b5ea0300ee3/vmlinux-a5618886.xz kernel image: https://storage.googleapis.com/syzbot-assets/47f59a45fc8c/Image-a5618886.gz.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+856397091bcfa77c8175@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: slab-use-after-free in __mm_populate+0x14c/0x3d8 mm/gup.c:2013 Read of size 8 at addr ffff0000fa4da6d0 by task syz.7.313/8381 CPU: 0 UID: 0 PID: 8381 Comm: syz.7.313 Not tainted 6.14.0-rc6-syzkaller-ga5618886fdab #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0x198/0x550 mm/kasan/report.c:521 kasan_report+0xd8/0x138 mm/kasan/report.c:634 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __mm_populate+0x14c/0x3d8 mm/gup.c:2013 mm_populate include/linux/mm.h:3386 [inline] vm_mmap_pgoff+0x304/0x3c4 mm/util.c:580 ksys_mmap_pgoff+0x3a4/0x5c8 mm/mmap.c:607 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Allocated by task 8381: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:562 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x254/0x410 mm/slub.c:4171 vm_area_alloc+0x30/0x1bc kernel/fork.c:472 __mmap_new_vma mm/vma.c:2345 [inline] __mmap_region mm/vma.c:2461 [inline] mmap_region+0x13ec/0x2518 mm/vma.c:2539 do_mmap+0xbc8/0x1150 mm/mmap.c:561 vm_mmap_pgoff+0x228/0x3c4 mm/util.c:575 ksys_mmap_pgoff+0x3a4/0x5c8 mm/mmap.c:607 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Freed by task 8500: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_free_info+0x54/0x6c mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x64/0x8c 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:4609 [inline] kmem_cache_free+0x198/0x554 mm/slub.c:4711 __vm_area_free+0xfc/0x148 kernel/fork.c:515 vm_area_free_rcu_cb+0x80/0xa4 kernel/fork.c:526 rcu_do_batch kernel/rcu/tree.c:2546 [inline] rcu_core+0x898/0x1b5c kernel/rcu/tree.c:2802 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2819 handle_softirqs+0x320/0xd34 kernel/softirq.c:561 __do_softirq+0x14/0x20 kernel/softirq.c:595 Last potentially related work creation: kasan_save_stack+0x40/0x6c mm/kasan/common.c:47 kasan_record_aux_stack+0xb4/0xcc mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3065 [inline] call_rcu+0x104/0xb9c kernel/rcu/tree.c:3172 vm_area_free+0x28/0x38 kernel/fork.c:533 remove_vma mm/vma.c:419 [inline] vms_complete_munmap_vmas+0x5ac/0x808 mm/vma.c:1202 vms_abort_munmap_vmas mm/vma.c:2215 [inline] __mmap_region mm/vma.c:2486 [inline] mmap_region+0xba4/0x2518 mm/vma.c:2539 do_mmap+0xbc8/0x1150 mm/mmap.c:561 vm_mmap_pgoff+0x228/0x3c4 mm/util.c:575 ksys_mmap_pgoff+0x3a4/0x5c8 mm/mmap.c:607 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 The buggy address belongs to the object at ffff0000fa4da6c8 which belongs to the cache vm_area_struct of size 184 The buggy address is located 8 bytes inside of freed 184-byte region [ffff0000fa4da6c8, ffff0000fa4da780) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13a4da memcg:ffff0000cee77f01 flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000000 ffff0000c1877b40 fffffdffc3569380 dead000000000004 raw: 0000000000000000 0000000000100010 00000000f5000000 ffff0000cee77f01 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000fa4da580: 00 00 fc fc fc fc fc fc fc fc 00 00 00 00 00 00 ffff0000fa4da600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000fa4da680: 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb ^ ffff0000fa4da700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000fa4da780: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ================================================================== ------------[ cut here ]------------ kernel BUG at mm/gup.c:1891! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 UID: 0 PID: 8381 Comm: syz.7.313 Tainted: G B 6.14.0-rc6-syzkaller-ga5618886fdab #0 Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : populate_vma_page_range+0x2c4/0x2f0 mm/gup.c:1891 lr : populate_vma_page_range+0x2c4/0x2f0 mm/gup.c:1891 sp : ffff80009d7e7a20 x29: ffff80009d7e7a80 x28: dfff800000000000 x27: ffff80009d7e7a20 x26: 1ffff00013afcf44 x25: dfff800000000000 x24: 0000000000000118 x23: 0000400000600000 x22: ffff0000fa4da6c8 x21: ffff0000d5372200 x20: ffff80009d7e7b20 x19: ffff0000f235f118 x18: 1fffe000366f1886 x17: ffff80008fbbd000 x16: ffff80008b7d1688 x15: 0000000000000001 x14: 1ffff0001262e8f8 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000080000 x10: 0000000000030d1d x9 : ffff8000a4ddd000 x8 : 0000000000030d1e x7 : 1fffe000366f1887 x6 : ffff8000803d5958 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800080a62780 x2 : 0000000000000000 x1 : 0000000000000118 x0 : 0000000000000000 Call trace: populate_vma_page_range+0x2c4/0x2f0 mm/gup.c:1891 (P) __mm_populate+0x240/0x3d8 mm/gup.c:2032 mm_populate include/linux/mm.h:3386 [inline] vm_mmap_pgoff+0x304/0x3c4 mm/util.c:580 ksys_mmap_pgoff+0x3a4/0x5c8 mm/mmap.c:607 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 Code: 9406604b 17ffffa3 95d32b09 97f0fdc7 (d4210000) ---[ end trace 0000000000000000 ]--- --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
