[syzbot] KASAN: slab-out-of-bounds Read in dtSearch

From: syzbot
Date: Sun Sep 25 2022 - 11:21:03 EST


Hello,

syzbot found the following issue on:

HEAD commit: 1a61b828566f Merge tag 'char-misc-6.0-rc7' of git://git.ke..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=145e5098880000
kernel config: https://syzkaller.appspot.com/x/.config?x=122d7bd4fc8e0ecb
dashboard link: https://syzkaller.appspot.com/bug?extid=9924e2a08d9ba0fd4ce2
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1708652f080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=112601ff080000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/367e34e7ff83/disk-1a61b828.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/91a2819fe451/vmlinux-1a61b828.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9924e2a08d9ba0fd4ce2@xxxxxxxxxxxxxxxxxxxxxxxxx

loop0: detected capacity change from 0 to 65535
==================================================================
BUG: KASAN: slab-out-of-bounds in ciCompare fs/jfs/jfs_dtree.c:3393 [inline]
BUG: KASAN: slab-out-of-bounds in dtSearch+0x1d88/0x2000 fs/jfs/jfs_dtree.c:639
Read of size 1 at addr ffff8880738eb714 by task syz-executor104/3605

CPU: 1 PID: 3605 Comm: syz-executor104 Not tainted 6.0.0-rc6-syzkaller-00309-g1a61b828566f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
ciCompare fs/jfs/jfs_dtree.c:3393 [inline]
dtSearch+0x1d88/0x2000 fs/jfs/jfs_dtree.c:639
jfs_lookup+0x17c/0x2f0 fs/jfs/namei.c:1454
lookup_open.isra.0+0x76a/0x12a0 fs/namei.c:3391
open_last_lookups fs/namei.c:3481 [inline]
path_openat+0x996/0x28f0 fs/namei.c:3688
do_filp_open+0x1b6/0x400 fs/namei.c:3718
do_sys_openat2+0x16d/0x4c0 fs/open.c:1313
do_sys_open fs/open.c:1329 [inline]
__do_sys_open fs/open.c:1337 [inline]
__se_sys_open fs/open.c:1333 [inline]
__x64_sys_open+0x119/0x1c0 fs/open.c:1333
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5b32967089
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffde79b8fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5b32967089
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0
RBP: 00007f5b32926850 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffde79b8ea0 R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00083878000000f8 R15: 0000000000000000
</TASK>

Allocated by task 3605:
kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:437 [inline]
__kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:470
kasan_slab_alloc include/linux/kasan.h:224 [inline]
slab_post_alloc_hook mm/slab.h:727 [inline]
slab_alloc_node mm/slub.c:3248 [inline]
slab_alloc mm/slub.c:3256 [inline]
__kmem_cache_alloc_lru mm/slub.c:3263 [inline]
kmem_cache_alloc_lru+0x255/0x720 mm/slub.c:3280
alloc_inode_sb include/linux/fs.h:3103 [inline]
jfs_alloc_inode+0x23/0x60 fs/jfs/super.c:105
alloc_inode+0x61/0x230 fs/inode.c:260
iget_locked+0x1b7/0x6f0 fs/inode.c:1287
jfs_iget+0x1a/0x4d0 fs/jfs/inode.c:29
jfs_fill_super+0x6a4/0xc70 fs/jfs/super.c:580
mount_bdev+0x34d/0x410 fs/super.c:1400
legacy_get_tree+0x105/0x220 fs/fs_context.c:610
vfs_get_tree+0x89/0x2f0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1326/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff8880738eae40
which belongs to the cache jfs_ip of size 2240
The buggy address is located 20 bytes to the right of
2240-byte region [ffff8880738eae40, ffff8880738eb700)

The buggy address belongs to the physical page:
page:ffffea0001ce3a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x738e8
head:ffffea0001ce3a00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff88814635d640
raw: 0000000000000000 00000000800d000d 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd2050(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_RECLAIMABLE), pid 3605, tgid 3605 (syz-executor104), ts 44185585735, free_ts 10115165657
prep_new_page mm/page_alloc.c:2532 [inline]
get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283
__alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515
alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270
alloc_slab_page mm/slub.c:1829 [inline]
allocate_slab+0x27e/0x3d0 mm/slub.c:1974
new_slab mm/slub.c:2034 [inline]
___slab_alloc+0x7f1/0xe10 mm/slub.c:3036
__slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123
slab_alloc_node mm/slub.c:3214 [inline]
slab_alloc mm/slub.c:3256 [inline]
__kmem_cache_alloc_lru mm/slub.c:3263 [inline]
kmem_cache_alloc_lru+0x528/0x720 mm/slub.c:3280
alloc_inode_sb include/linux/fs.h:3103 [inline]
jfs_alloc_inode+0x23/0x60 fs/jfs/super.c:105
alloc_inode+0x61/0x230 fs/inode.c:260
new_inode_pseudo fs/inode.c:1019 [inline]
new_inode+0x27/0x270 fs/inode.c:1047
jfs_fill_super+0x436/0xc70 fs/jfs/super.c:544
mount_bdev+0x34d/0x410 fs/super.c:1400
legacy_get_tree+0x105/0x220 fs/fs_context.c:610
vfs_get_tree+0x89/0x2f0 fs/super.c:1530
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x1326/0x1e20 fs/namespace.c:3370
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1449 [inline]
free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499
free_unref_page_prepare mm/page_alloc.c:3380 [inline]
free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476
free_contig_range+0xb1/0x180 mm/page_alloc.c:9408
destroy_args+0xa8/0x646 mm/debug_vm_pgtable.c:1031
debug_vm_pgtable+0x2945/0x29d6 mm/debug_vm_pgtable.c:1354
do_one_initcall+0xfe/0x650 init/main.c:1296
do_initcall_level init/main.c:1369 [inline]
do_initcalls init/main.c:1385 [inline]
do_basic_setup init/main.c:1404 [inline]
kernel_init_freeable+0x6b1/0x73a init/main.c:1623
kernel_init+0x1a/0x1d0 init/main.c:1512
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

Memory state around the buggy address:
ffff8880738eb600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880738eb680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880738eb700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8880738eb780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880738eb800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


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