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

syzbot
2025-03-13T04:06:15Z

> #syz test: linux-next

want either no args or 2 args (repo, branch), got 6

>
> On 3/5/25 00:15, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 99fa936e8e4f Merge tag 'affs-6.14-rc5-tag' of git://git.ke..
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=111c9464580000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=2040405600e83619
>> dashboard link: https://syzkaller.appspot.com/bug?extid=9f6d080dece587cfdd4c
>> compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=132f0078580000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1483fc54580000
>>
>> Downloadable assets:
>> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-99fa936e.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/ef04f83d96f6/vmlinux-99fa936e.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/583a7eea5c8e/bzImage-99fa936e.xz
>> mounted in repro: https://storage.googleapis.com/syzbot-assets/6232fcdbddfb/mount_1.gz
>> fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=11d457a0580000)
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+9f6d080dece587cfdd4c@syzkaller.appspotmail.com
>>
>> =======================================================
>> XFS (loop0): Mounting V5 Filesystem bfdc47fc-10d8-4eed-a562-11a831b3f791
>> ==================================================================
>> BUG: KASAN: slab-out-of-bounds in crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81
>> Read of size 8 at addr ffff888040dfea00 by task syz-executor260/5304
>>
>> CPU: 0 UID: 0 PID: 5304 Comm: syz-executor260 Not tainted 6.14.0-rc5-syzkaller-00013-g99fa936e8e4f #0
>> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
>> Call Trace:
>> <TASK>
>> __dump_stack lib/dump_stack.c:94 [inline]
>> dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
>> print_address_description mm/kasan/report.c:408 [inline]
>> print_report+0x16e/0x5b0 mm/kasan/report.c:521
>> kasan_report+0x143/0x180 mm/kasan/report.c:634
>> crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81
>> __crc32c_le include/linux/crc32.h:36 [inline]
>> crc32c include/linux/crc32c.h:9 [inline]
>> xlog_cksum+0x91/0xf0 fs/xfs/xfs_log.c:1588
>> xlog_recover_process+0x78/0x1e0 fs/xfs/xfs_log_recover.c:2900
>> xlog_do_recovery_pass+0xa01/0xdc0 fs/xfs/xfs_log_recover.c:3235
>> xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
>> xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315
>> xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3419
>> xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
>> xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
>> xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
>> get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
>> vfs_get_tree+0x90/0x2b0 fs/super.c:1814
>> do_new_mount+0x2be/0xb40 fs/namespace.c:3560
>> do_mount fs/namespace.c:3900 [inline]
>> __do_sys_mount fs/namespace.c:4111 [inline]
>> __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
>> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>> RIP: 0033:0x7ff347850dfa
>> Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffcece53ae8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
>> RAX: ffffffffffffffda RBX: 00007ffcece53b00 RCX: 00007ff347850dfa
>> RDX: 0000400000000500 RSI: 0000400000000200 RDI: 00007ffcece53b00
>> RBP: 0000400000000500 R08: 00007ffcece53b40 R09: 002c6563726f666e
>> R10: 0000000002218a5d R11: 0000000000000202 R12: 0000400000000200
>> R13: 0000000000000005 R14: 0000000000000004 R15: 00007ffcece53b40
>> </TASK>
>>
>> Allocated by task 5304:
>> kasan_save_stack mm/kasan/common.c:47 [inline]
>> kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
>> poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
>> __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
>> kasan_kmalloc include/linux/kasan.h:260 [inline]
>> __do_kmalloc_node mm/slub.c:4294 [inline]
>> __kmalloc_node_noprof+0x290/0x4d0 mm/slub.c:4300
>> __kvmalloc_node_noprof+0x72/0x190 mm/util.c:662
>> xlog_do_recovery_pass+0x143/0xdc0 fs/xfs/xfs_log_recover.c:3016
>> xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
>> xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315
>> xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3419
>> xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
>> xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
>> xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
>> get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
>> vfs_get_tree+0x90/0x2b0 fs/super.c:1814
>> do_new_mount+0x2be/0xb40 fs/namespace.c:3560
>> do_mount fs/namespace.c:3900 [inline]
>> __do_sys_mount fs/namespace.c:4111 [inline]
>> __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
>> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>
>> The buggy address belongs to the object at ffff888040dfe800
>> which belongs to the cache kmalloc-512 of size 512
>> The buggy address is located 0 bytes to the right of
>> allocated 512-byte region [ffff888040dfe800, ffff888040dfea00)
>>
>> The buggy address belongs to the physical page:
>> page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x40dfe
>> head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
>> flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
>> page_type: f5(slab)
>> raw: 04fff00000000040 ffff88801b041c80 ffffea0000d6ab00 dead000000000004
>> raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
>> head: 04fff00000000040 ffff88801b041c80 ffffea0000d6ab00 dead000000000004
>> head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
>> head: 04fff00000000001 ffffea0001037f81 ffffffffffffffff 0000000000000000
>> head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
>> page dumped because: kasan: bad access detected
>> page_owner tracks the page as allocated
>> page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2, tgid 2 (kthreadd), ts 25533552797, free_ts 0
>> set_page_owner include/linux/page_owner.h:32 [inline]
>> post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
>> prep_new_page mm/page_alloc.c:1559 [inline]
>> get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
>> __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
>> alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
>> alloc_slab_page mm/slub.c:2423 [inline]
>> allocate_slab+0x8f/0x3a0 mm/slub.c:2587
>> new_slab mm/slub.c:2640 [inline]
>> ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
>> __slab_alloc+0x58/0xa0 mm/slub.c:3916
>> __slab_alloc_node mm/slub.c:3991 [inline]
>> slab_alloc_node mm/slub.c:4152 [inline]
>> __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4320
>> kmalloc_noprof include/linux/slab.h:901 [inline]
>> kzalloc_noprof include/linux/slab.h:1037 [inline]
>> set_kthread_struct+0xc2/0x330 kernel/kthread.c:126
>> copy_process+0x1179/0x3cf0 kernel/fork.c:2331
>> kernel_clone+0x226/0x8e0 kernel/fork.c:2815
>> kernel_thread+0x1c0/0x250 kernel/fork.c:2877
>> create_kthread kernel/kthread.c:487 [inline]
>> kthreadd+0x60d/0x810 kernel/kthread.c:847
>> ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
>> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>> page_owner free stack trace missing
>>
>> Memory state around the buggy address:
>> ffff888040dfe900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>> ffff888040dfe980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>>> ffff888040dfea00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>> ^
>> ffff888040dfea80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>> ffff888040dfeb00: fc fc fc fc fc fc 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:
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>>
>> If the report is already addressed, let syzbot know by replying with:
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>>
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>> #syz test: git://repo/address.git branch-or-commit-hash
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>>
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>>
>> If the report is a duplicate of another one, reply with:
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>>
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>