Re: [syzbot] [xfs?] KASAN: slab-out-of-bounds Read in xfs_getbmap

syzbot
2023-05-02T21:20:30Z

> On Mon, May 01, 2023 at 11:53:47AM -0700, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 58390c8ce1bd Merge tag 'iommu-updates-v6.4' of git://git.k..
>> git tree: upstream
>> console+strace: https://syzkaller.appspot.com/x/log.txt?x=11e6af2c280000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=5eadbf0d3c2ece89
>> dashboard link: https://syzkaller.appspot.com/bug?extid=c103d3808a0de5faaf80
>> compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12e25f2c280000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14945d10280000
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/60130779f509/disk-58390c8c.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/d7f0cdd29b71/vmlinux-58390c8c.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/de415ad52ae4/bzImage-58390c8c.xz
>> mounted in repro: https://storage.googleapis.com/syzbot-assets/c94bae2c94e1/mount_0.gz
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+c103d3808a0de5faaf80@syzkaller.appspotmail.com
>>
>> ==================================================================
>> BUG: KASAN: slab-out-of-bounds in xfs_getbmap+0x1c06/0x1c90 fs/xfs/xfs_bmap_util.c:561
>> Read of size 4 at addr ffff88801872aa78 by task syz-executor294/5000
>>
>> CPU: 1 PID: 5000 Comm: syz-executor294 Not tainted 6.3.0-syzkaller-12049-g58390c8ce1bd #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
>> Call Trace:
>> <TASK>
>> __dump_stack lib/dump_stack.c:88 [inline]
>> dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
>> print_address_description mm/kasan/report.c:351 [inline]
>> print_report+0x163/0x540 mm/kasan/report.c:462
>> kasan_report+0x176/0x1b0 mm/kasan/report.c:572
>> xfs_getbmap+0x1c06/0x1c90 fs/xfs/xfs_bmap_util.c:561
>> xfs_ioc_getbmap+0x243/0x7a0 fs/xfs/xfs_ioctl.c:1481
>> xfs_file_ioctl+0xbf5/0x16a0 fs/xfs/xfs_ioctl.c:1949
>> vfs_ioctl fs/ioctl.c:51 [inline]
>> __do_sys_ioctl fs/ioctl.c:870 [inline]
>> __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>> RIP: 0033:0x7fc886bade49
>> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 15 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
>> RSP: 002b:00007fc87f738208 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
>> RAX: ffffffffffffffda RBX: 00007fc886c3c7b8 RCX: 00007fc886bade49
>> RDX: 0000000020000140 RSI: 00000000c0205826 RDI: 0000000000000005
>> RBP: 00007fc886c3c7b0 R08: 00007fc87f738700 R09: 0000000000000000
>> R10: 00007fc87f738700 R11: 0000000000000246 R12: 00007fc886c3c7bc
>> R13: 00007ffdc483022f R14: 00007fc87f738300 R15: 0000000000022000
>> </TASK>
>>
>> Allocated by task 4450:
>> kasan_save_stack mm/kasan/common.c:45 [inline]
>> kasan_set_track+0x4f/0x70 mm/kasan/common.c:52
>> ____kasan_kmalloc mm/kasan/common.c:374 [inline]
>> __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383
>> kasan_kmalloc include/linux/kasan.h:196 [inline]
>> __do_kmalloc_node mm/slab_common.c:966 [inline]
>> __kmalloc_node+0xb8/0x230 mm/slab_common.c:973
>> kmalloc_node include/linux/slab.h:579 [inline]
>> kvmalloc_node+0x72/0x180 mm/util.c:604
>> kvmalloc include/linux/slab.h:697 [inline]
>> simple_xattr_alloc+0x43/0xa0 fs/xattr.c:1073
>> shmem_initxattrs+0x8e/0x1e0 mm/shmem.c:3290
>> security_inode_init_security+0x2df/0x3f0 security/security.c:1630
>> shmem_mknod+0xba/0x1c0 mm/shmem.c:2947
>> lookup_open fs/namei.c:3492 [inline]
>> open_last_lookups fs/namei.c:3560 [inline]
>> path_openat+0x13df/0x3170 fs/namei.c:3788
>> do_filp_open+0x234/0x490 fs/namei.c:3818
>> do_sys_openat2+0x13f/0x500 fs/open.c:1356
>> do_sys_open fs/open.c:1372 [inline]
>> __do_sys_openat fs/open.c:1388 [inline]
>> __se_sys_openat fs/open.c:1383 [inline]
>> __x64_sys_openat+0x247/0x290 fs/open.c:1383
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>>
>> The buggy address belongs to the object at ffff88801872aa00
>> which belongs to the cache kmalloc-64 of size 64
>> The buggy address is located 79 bytes to the right of
>> allocated 41-byte region [ffff88801872aa00, ffff88801872aa29)
>>
>> The buggy address belongs to the physical page:
>> page:ffffea000061ca80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1872a
>> flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
>> page_type: 0xffffffff()
>> raw: 00fff00000000200 ffff888012441640 ffffea0000ad39c0 dead000000000002
>> raw: 0000000000000000 0000000080200020 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 4439, tgid 4439 (S02sysctl), ts 15189537421, free_ts 15177747790
>> set_page_owner include/linux/page_owner.h:31 [inline]
>> post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1722
>> prep_new_page mm/page_alloc.c:1729 [inline]
>> get_page_from_freelist+0x321c/0x33a0 mm/page_alloc.c:3493
>> __alloc_pages+0x255/0x670 mm/page_alloc.c:4759
>> alloc_slab_page+0x6a/0x160 mm/slub.c:1851
>> allocate_slab mm/slub.c:1998 [inline]
>> new_slab+0x84/0x2f0 mm/slub.c:2051
>> ___slab_alloc+0xa85/0x10a0 mm/slub.c:3192
>> __slab_alloc mm/slub.c:3291 [inline]
>> __slab_alloc_node mm/slub.c:3344 [inline]
>> slab_alloc_node mm/slub.c:3441 [inline]
>> __kmem_cache_alloc_node+0x1b8/0x290 mm/slub.c:3490
>> kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1057
>> kmalloc include/linux/slab.h:559 [inline]
>> load_elf_binary+0x1cdb/0x2830 fs/binfmt_elf.c:910
>> search_binary_handler fs/exec.c:1737 [inline]
>> exec_binprm fs/exec.c:1779 [inline]
>> bprm_execve+0x90e/0x1740 fs/exec.c:1854
>> do_execveat_common+0x580/0x720 fs/exec.c:1962
>> do_execve fs/exec.c:2036 [inline]
>> __do_sys_execve fs/exec.c:2112 [inline]
>> __se_sys_execve fs/exec.c:2107 [inline]
>> __x64_sys_execve+0x92/0xa0 fs/exec.c:2107
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>> page last free stack trace:
>> reset_page_owner include/linux/page_owner.h:24 [inline]
>> free_pages_prepare mm/page_alloc.c:1302 [inline]
>> free_unref_page_prepare+0x903/0xa30 mm/page_alloc.c:2555
>> free_unref_page_list+0x596/0x830 mm/page_alloc.c:2696
>> release_pages+0x2193/0x2470 mm/swap.c:1042
>> tlb_batch_pages_flush mm/mmu_gather.c:97 [inline]
>> tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
>> tlb_flush_mmu+0x100/0x210 mm/mmu_gather.c:299
>> tlb_finish_mmu+0xd4/0x1f0 mm/mmu_gather.c:391
>> exit_mmap+0x3da/0xaf0 mm/mmap.c:3123
>> __mmput+0x115/0x3c0 kernel/fork.c:1351
>> exec_mmap+0x672/0x700 fs/exec.c:1035
>> begin_new_exec+0x665/0xf10 fs/exec.c:1294
>> load_elf_binary+0x95d/0x2830 fs/binfmt_elf.c:1001
>> search_binary_handler fs/exec.c:1737 [inline]
>> exec_binprm fs/exec.c:1779 [inline]
>> bprm_execve+0x90e/0x1740 fs/exec.c:1854
>> do_execveat_common+0x580/0x720 fs/exec.c:1962
>> do_execve fs/exec.c:2036 [inline]
>> __do_sys_execve fs/exec.c:2112 [inline]
>> __se_sys_execve fs/exec.c:2107 [inline]
>> __x64_sys_execve+0x92/0xa0 fs/exec.c:2107
>> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
>> entry_SYSCALL_64_after_hwframe+0x63/0xcd
>>
>> Memory state around the buggy address:
>> ffff88801872a900: 00 00 00 00 00 01 fc fc fc fc fc fc fc fc fc fc
>> ffff88801872a980: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>> >ffff88801872aa00: 00 00 00 00 00 01 fc fc fc fc fc fc fc fc fc fc
>> ^
>> ffff88801872aa80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>> ffff88801872ab00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>> ==================================================================
>>
>>
>> ---
>> 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@googlegroups.com.
>>
>> syzbot will keep track of this issue. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>>
>> If the bug is already fixed, let syzbot know by replying with:
>> #syz fix: exact-commit-title
>>
>> If you want syzbot to run the reproducer, reply with:
> #syz test: upstream

want 2 args (repo, branch), got 4

>
> (does that work?)
>
> --D