syzbot


KASAN: slab-out-of-bounds Read in __hfs_brec_find

Status: fixed on 2023/02/24 13:50
Subsystems: hfs
[Documentation on labels]
Reported-by: syzbot+e836ff7133ac02be825f@syzkaller.appspotmail.com
Fix commit: 8d824e69d9f3 hfs: fix OOB Read in __hfs_brec_find
First crash: 459d, last: 444d
Discussions (10)
Title Replies (including bot) Last reply
[PATCH AUTOSEL 6.1 01/22] fs: jfs: fix shift-out-of-bounds in dbAllocAG 24 (24) 2022/12/18 11:28
[PATCH AUTOSEL 6.0 01/16] fs: jfs: fix shift-out-of-bounds in dbAllocAG 18 (18) 2022/12/18 11:26
[PATCH AUTOSEL 5.4 1/9] fs: jfs: fix shift-out-of-bounds in dbAllocAG 10 (10) 2022/12/17 18:05
[PATCH AUTOSEL 4.9 1/8] fs: jfs: fix shift-out-of-bounds in dbAllocAG 8 (8) 2022/12/17 15:30
[PATCH AUTOSEL 4.14 1/8] fs: jfs: fix shift-out-of-bounds in dbAllocAG 8 (8) 2022/12/17 15:30
[PATCH AUTOSEL 4.19 1/8] fs: jfs: fix shift-out-of-bounds in dbAllocAG 8 (8) 2022/12/17 15:30
[PATCH AUTOSEL 5.10 1/9] fs: jfs: fix shift-out-of-bounds in dbAllocAG 9 (9) 2022/12/17 15:29
[PATCH AUTOSEL 5.15 01/10] fs: jfs: fix shift-out-of-bounds in dbAllocAG 10 (10) 2022/12/17 15:29
[PATCH] hfs: Fix OOB Read in __hfs_brec_find 2 (2) 2022/11/30 19:23
[syzbot] KASAN: slab-out-of-bounds Read in __hfs_brec_find 0 (1) 2022/11/28 10:01

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in hfs_strcmp+0x117/0x190 fs/hfs/string.c:84
Read of size 1 at addr ffff88801e101dce by task kworker/u4:2/33

CPU: 1 PID: 33 Comm: kworker/u4:2 Not tainted 6.1.0-rc7-syzkaller-00102-g04aa64375f48 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
 print_address_description+0x74/0x340 mm/kasan/report.c:284
 print_report+0x107/0x1f0 mm/kasan/report.c:395
 kasan_report+0xcd/0x100 mm/kasan/report.c:495
 hfs_strcmp+0x117/0x190 fs/hfs/string.c:84
 __hfs_brec_find+0x213/0x5c0 fs/hfs/bfind.c:75
 hfs_brec_find+0x276/0x520 fs/hfs/bfind.c:138
 hfs_write_inode+0x34c/0xb40 fs/hfs/inode.c:462
 write_inode fs/fs-writeback.c:1440 [inline]
 __writeback_single_inode+0x4d6/0x670 fs/fs-writeback.c:1652
 writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1878
 wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2052
 wb_do_writeback fs/fs-writeback.c:2195 [inline]
 wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2235
 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Allocated by task 33:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x3d/0x60 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:371 [inline]
 __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:380
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:955 [inline]
 __kmalloc+0xaf/0x1a0 mm/slab_common.c:968
 kmalloc include/linux/slab.h:558 [inline]
 hfs_find_init+0x8b/0x1e0 fs/hfs/bfind.c:21
 hfs_write_inode+0x2e6/0xb40 fs/hfs/inode.c:457
 write_inode fs/fs-writeback.c:1440 [inline]
 __writeback_single_inode+0x4d6/0x670 fs/fs-writeback.c:1652
 writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1878
 wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2052
 wb_do_writeback fs/fs-writeback.c:2195 [inline]
 wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2235
 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

The buggy address belongs to the object at ffff88801e101d80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 78 bytes inside of
 96-byte region [ffff88801e101d80, ffff88801e101de0)

The buggy address belongs to the physical page:
page:ffffea0000784040 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801e101100 pfn:0x1e101
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000765400 dead000000000006 ffff888012841780
raw: ffff88801e101100 000000008020001e 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 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 3007, tgid 3007 (udevd), ts 24956538100, free_ts 24951907466
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x742/0x7c0 mm/page_alloc.c:4291
 __alloc_pages+0x259/0x560 mm/page_alloc.c:5558
 alloc_slab_page+0x70/0xf0 mm/slub.c:1794
 allocate_slab+0x5e/0x4b0 mm/slub.c:1939
 new_slab mm/slub.c:1992 [inline]
 ___slab_alloc+0x782/0xe20 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 __kmem_cache_alloc_node+0x252/0x310 mm/slub.c:3437
 __do_kmalloc_node mm/slab_common.c:954 [inline]
 __kmalloc+0x9e/0x1a0 mm/slab_common.c:968
 kmalloc include/linux/slab.h:558 [inline]
 kzalloc include/linux/slab.h:689 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x5ae/0x5f0 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x1f0/0x460 security/tomoyo/file.c:771
 security_file_open+0x50/0x560 security/security.c:1648
 do_dentry_open+0x306/0x11b0 fs/open.c:869
 do_open fs/namei.c:3557 [inline]
 path_openat+0x25fc/0x2df0 fs/namei.c:3714
 do_filp_open+0x264/0x4f0 fs/namei.c:3741
 do_sys_openat2+0x124/0x4e0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1337
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare+0x80c/0x8f0 mm/page_alloc.c:1509
 free_unref_page_prepare mm/page_alloc.c:3387 [inline]
 free_unref_page+0x7d/0x5f0 mm/page_alloc.c:3483
 free_pipe_info+0x302/0x380 fs/pipe.c:851
 put_pipe_info fs/pipe.c:711 [inline]
 pipe_release+0x232/0x310 fs/pipe.c:734
 __fput+0x3ba/0x880 fs/file_table.c:320
 task_work_run+0x243/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x124/0x150 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff88801e101c80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff88801e101d00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88801e101d80: 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc fc
                                              ^
 ffff88801e101e00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88801e101e80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/12/01 10:06 upstream 04aa64375f48 4c2a66e8 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-out-of-bounds Read in __hfs_brec_find
2022/11/27 03:07 upstream 644e9524388a f4470a7b .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs KASAN: slab-out-of-bounds Read in __hfs_brec_find
2022/12/12 09:30 upstream 4cee37b3a4e6 67be1ae7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-out-of-bounds Read in __hfs_brec_find
2022/12/04 07:43 upstream c2bf05db6c78 e080de16 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-out-of-bounds Read in __hfs_brec_find
2022/11/27 02:35 upstream 644e9524388a f4470a7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: slab-out-of-bounds Read in __hfs_brec_find
* Struck through repros no longer work on HEAD.