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

From: syzbot
Date: Wed Mar 05 2025 - 07:28:15 EST

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In reply to: Edward Adam Davis: "Re: [syzbot] [xfs?] KASAN: slab-out-of-bounds Read in xlog_cksum"
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Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-out-of-bounds Read in xlog_cksum

hlen: 64512, bufsize: 65536, xlog_valid_rec_header
hlen: 64512, bufsize: 65536, xlog_valid_rec_header
xheads: 2, size: 64512, xlog_cksum
==================================================================
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 ffff88804899fa00 by task syz.0.16/5851

CPU: 0 UID: 0 PID: 5851 Comm: syz.0.16 Not tainted 6.14.0-rc5-syzkaller-g48a5eed9ad58-dirty #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+0xcb/0x130 fs/xfs/xfs_log.c:1589
xlog_recover_process+0x78/0x1e0 fs/xfs/xfs_log_recover.c:2900
xlog_do_recovery_pass+0xa01/0xdc0 fs/xfs/xfs_log_recover.c:3236
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:3420
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: 0033:0x7f5c0bb8e90a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5c0ca1fe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5c0ca1fef0 RCX: 00007f5c0bb8e90a
RDX: 0000400000000500 RSI: 0000400000000200 RDI: 00007f5c0ca1feb0
RBP: 0000400000000500 R08: 00007f5c0ca1fef0 R09: 0000000002218a5d
R10: 0000000002218a5d R11: 0000000000000246 R12: 0000400000000200
R13: 00007f5c0ca1feb0 R14: 0000000000009706 R15: 0000400000000100
</TASK>

Allocated by task 5851:
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:3017
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:3420
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 ffff88804899f800
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 [ffff88804899f800, ffff88804899fa00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4899e
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 04fff00000000001 ffffea0001226781 ffffffffffffffff 0000000000000000
head: 0000000700000002 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 5614, tgid 5614 (syz-executor), ts 129766503794, free_ts 128754914187
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]
__do_kmalloc_node mm/slub.c:4293 [inline]
__kmalloc_noprof+0x2e6/0x4c0 mm/slub.c:4306
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
ops_init+0x76/0x5b0 net/core/net_namespace.c:128
setup_net+0x287/0x9e0 net/core/net_namespace.c:362
copy_net_ns+0x33f/0x570 net/core/net_namespace.c:516
create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x57d/0xa70 kernel/fork.c:3342
__do_sys_unshare kernel/fork.c:3413 [inline]
__se_sys_unshare kernel/fork.c:3411 [inline]
__x64_sys_unshare+0x38/0x40 kernel/fork.c:3411
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
page last free pid 5603 tgid 5603 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]
free_unref_folios+0xe40/0x18b0 mm/page_alloc.c:2707
folios_put_refs+0x76c/0x860 mm/swap.c:994
free_pages_and_swap_cache+0x2e5/0x690 mm/swap_state.c:331
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:389 [inline]
tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:396
tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:488
vms_clear_ptes+0x432/0x530 mm/vma.c:1144
vms_complete_munmap_vmas+0x210/0x8f0 mm/vma.c:1186
do_vmi_align_munmap+0x5ef/0x6f0 mm/vma.c:1445
do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1493
__vm_munmap+0x372/0x510 mm/vma.c:2951
__do_sys_munmap mm/mmap.c:1084 [inline]
__se_sys_munmap mm/mmap.c:1081 [inline]
__x64_sys_munmap+0x60/0x70 mm/mmap.c:1081
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

Memory state around the buggy address:
ffff88804899f900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88804899f980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804899fa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88804899fa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804899fb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Tested on:

commit: 48a5eed9 Merge tag 'devicetree-fixes-for-6.14-2' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12d2fc64580000
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
patch: https://syzkaller.appspot.com/x/patch.diff?x=10f938b7980000

Next message: Mimi Zohar: "Re: [PATCH v9 1/7] ima: copy only complete measurement records across kexec"
Previous message: Bryan O'Donoghue: "Re: [PATCH v2] arm64: dts: qcom: sc7280: drop video decoder and encoder nodes"
In reply to: Edward Adam Davis: "Re: [syzbot] [xfs?] KASAN: slab-out-of-bounds Read in xlog_cksum"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]