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

From: syzbot
Date: Tue Jan 24 2023 - 04:29:40 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 081edded9b38 Merge tag 'zonefs-6.2-rc5' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16e2a4fe480000
kernel config: https://syzkaller.appspot.com/x/.config?x=d24faf5fc10540ae
dashboard link: https://syzkaller.appspot.com/bug?extid=fdd050b6b63ef0e6e29f
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e03f6355f8c4/disk-081edded.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ba84ff280ef5/vmlinux-081edded.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6ba2dbf91192/bzImage-081edded.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fdd050b6b63ef0e6e29f@xxxxxxxxxxxxxxxxxxxxxxxxx

XFS (loop0): Metadata corruption detected at xfs_btree_lookup_get_block+0x565/0x6d0 fs/xfs/libxfs/xfs_btree.c:1846, xfs_refcountbt block 0x28
XFS (loop0): Unmount and run xfs_repair
==================================================================
BUG: KASAN: slab-out-of-bounds in xfs_btree_del_cursor+0x96/0x2a0 fs/xfs/libxfs/xfs_btree.c:439
Read of size 8 at addr ffff88801e8735f0 by task syz-executor.0/27912

CPU: 1 PID: 27912 Comm: syz-executor.0 Not tainted 6.2.0-rc4-syzkaller-00069-g081edded9b38 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:306
print_report+0x107/0x1f0 mm/kasan/report.c:417
kasan_report+0xcd/0x100 mm/kasan/report.c:517
xfs_btree_del_cursor+0x96/0x2a0 fs/xfs/libxfs/xfs_btree.c:439
xfs_refcount_recover_cow_leftovers+0x2df/0xa60 fs/xfs/libxfs/xfs_refcount.c:1948
xfs_reflink_recover_cow+0xab/0x1b0 fs/xfs/xfs_reflink.c:928
xlog_recover_finish+0x824/0x920 fs/xfs/xfs_log_recover.c:3493
xfs_log_mount_finish+0x1ec/0x3d0 fs/xfs/xfs_log.c:829
xfs_mountfs+0x146a/0x1ef0 fs/xfs/xfs_mount.c:933
xfs_fs_fill_super+0xf95/0x11f0 fs/xfs/xfs_super.c:1666
get_tree_bdev+0x400/0x620 fs/super.c:1282
vfs_get_tree+0x88/0x270 fs/super.c:1489
do_new_mount+0x289/0xad0 fs/namespace.c:3145
do_mount fs/namespace.c:3488 [inline]
__do_sys_mount fs/namespace.c:3697 [inline]
__se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f9795c8d5fa
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 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:00007f9796aacf88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000000097a0 RCX: 00007f9795c8d5fa
RDX: 0000000020000040 RSI: 0000000020000180 RDI: 00007f9796aacfe0
RBP: 00007f9796aad020 R08: 00007f9796aad020 R09: 0000000000800003
R10: 0000000000800003 R11: 0000000000000202 R12: 0000000020000040
R13: 0000000020000180 R14: 00007f9796aacfe0 R15: 0000000020000080
</TASK>

Allocated by task 27912:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x3d/0x60 mm/kasan/common.c:52
__kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:325
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slab.h:761 [inline]
slab_alloc_node mm/slub.c:3452 [inline]
slab_alloc mm/slub.c:3460 [inline]
__kmem_cache_alloc_lru mm/slub.c:3467 [inline]
kmem_cache_alloc+0x1b3/0x350 mm/slub.c:3476
kmem_cache_zalloc include/linux/slab.h:710 [inline]
xfs_btree_alloc_cursor fs/xfs/libxfs/xfs_btree.h:592 [inline]
xfs_refcountbt_init_common fs/xfs/libxfs/xfs_refcount_btree.c:336 [inline]
xfs_refcountbt_init_cursor+0x84/0x330 fs/xfs/libxfs/xfs_refcount_btree.c:363
xfs_refcount_recover_cow_leftovers+0x213/0xa60 fs/xfs/libxfs/xfs_refcount.c:1939
xfs_reflink_recover_cow+0xab/0x1b0 fs/xfs/xfs_reflink.c:928
xlog_recover_finish+0x824/0x920 fs/xfs/xfs_log_recover.c:3493
xfs_log_mount_finish+0x1ec/0x3d0 fs/xfs/xfs_log.c:829
xfs_mountfs+0x146a/0x1ef0 fs/xfs/xfs_mount.c:933
xfs_fs_fill_super+0xf95/0x11f0 fs/xfs/xfs_super.c:1666
get_tree_bdev+0x400/0x620 fs/super.c:1282
vfs_get_tree+0x88/0x270 fs/super.c:1489
do_new_mount+0x289/0xad0 fs/namespace.c:3145
do_mount fs/namespace.c:3488 [inline]
__do_sys_mount fs/namespace.c:3697 [inline]
__se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff88801e873528
which belongs to the cache xfs_refcbt_cur of size 200
The buggy address is located 0 bytes to the right of
200-byte region [ffff88801e873528, ffff88801e8735f0)

The buggy address belongs to the physical page:
page:ffffea00007a1cc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801e873000 pfn:0x1e873
anon flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffff88814639e8c0 0000000000000000 0000000000000001
raw: ffff88801e873000 00000000800f0006 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 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5813, tgid 5812 (syz-executor.1), ts 240974207332, free_ts 240939470118
prep_new_page mm/page_alloc.c:2531 [inline]
get_page_from_freelist+0x742/0x7c0 mm/page_alloc.c:4283
__alloc_pages+0x259/0x560 mm/page_alloc.c:5549
alloc_slab_page+0xbd/0x190 mm/slub.c:1851
allocate_slab+0x5e/0x3c0 mm/slub.c:1998
new_slab mm/slub.c:2051 [inline]
___slab_alloc+0x782/0xe20 mm/slub.c:3193
__slab_alloc mm/slub.c:3292 [inline]
__slab_alloc_node mm/slub.c:3345 [inline]
slab_alloc_node mm/slub.c:3442 [inline]
slab_alloc mm/slub.c:3460 [inline]
__kmem_cache_alloc_lru mm/slub.c:3467 [inline]
kmem_cache_alloc+0x268/0x350 mm/slub.c:3476
kmem_cache_zalloc include/linux/slab.h:710 [inline]
xfs_btree_alloc_cursor fs/xfs/libxfs/xfs_btree.h:592 [inline]
xfs_refcountbt_init_common fs/xfs/libxfs/xfs_refcount_btree.c:336 [inline]
xfs_refcountbt_init_cursor+0x84/0x330 fs/xfs/libxfs/xfs_refcount_btree.c:363
xfs_refcount_recover_cow_leftovers+0x213/0xa60 fs/xfs/libxfs/xfs_refcount.c:1939
xfs_reflink_recover_cow+0xab/0x1b0 fs/xfs/xfs_reflink.c:928
xlog_recover_finish+0x824/0x920 fs/xfs/xfs_log_recover.c:3493
xfs_log_mount_finish+0x1ec/0x3d0 fs/xfs/xfs_log.c:829
xfs_mountfs+0x146a/0x1ef0 fs/xfs/xfs_mount.c:933
xfs_fs_fill_super+0xf95/0x11f0 fs/xfs/xfs_super.c:1666
get_tree_bdev+0x400/0x620 fs/super.c:1282
vfs_get_tree+0x88/0x270 fs/super.c:1489
do_new_mount+0x289/0xad0 fs/namespace.c:3145
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1446 [inline]
free_pcp_prepare+0x751/0x780 mm/page_alloc.c:1496
free_unref_page_prepare mm/page_alloc.c:3369 [inline]
free_unref_page_list+0xb2/0x830 mm/page_alloc.c:3510
release_pages+0x233e/0x25e0 mm/swap.c:1076
tlb_batch_pages_flush mm/mmu_gather.c:97 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:292 [inline]
tlb_flush_mmu+0x860/0xa80 mm/mmu_gather.c:299
tlb_finish_mmu+0xcd/0x200 mm/mmu_gather.c:391
exit_mmap+0x275/0x630 mm/mmap.c:3100
__mmput+0x114/0x3b0 kernel/fork.c:1207
exec_mmap+0x4af/0x530 fs/exec.c:1033
begin_new_exec+0x772/0xfb0 fs/exec.c:1292
load_elf_binary+0x8f0/0x2830 fs/binfmt_elf.c:996
search_binary_handler fs/exec.c:1735 [inline]
exec_binprm fs/exec.c:1777 [inline]
bprm_execve+0x8dc/0x1590 fs/exec.c:1851
do_execveat_common+0x598/0x750 fs/exec.c:1956
do_execve fs/exec.c:2030 [inline]
__do_sys_execve fs/exec.c:2106 [inline]
__se_sys_execve fs/exec.c:2101 [inline]
__x64_sys_execve+0x8e/0xa0 fs/exec.c:2101
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
ffff88801e873480: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
ffff88801e873500: fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00
>ffff88801e873580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
^
ffff88801e873600: fc fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb
ffff88801e873680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
==================================================================

---
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Next message: syzbot: "[syzbot] KASAN: use-after-free Read in hiddev_disconnect (5)"
Previous message: Salvatore Bonaccorso: "Re: amd_pmc module not autoloading on Thinkpad X13 Gen 2a"
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