syzbot


KASAN: slab-out-of-bounds Write in hfs_asc2mac

Status: upstream: reported C repro on 2022/12/02 20:22
Subsystems: hfs
[Documentation on labels]
Reported-by: syzbot+8cb1c80b7b7e4e51fea5@syzkaller.appspotmail.com
First crash: 508d, last: 416d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 KASAN: slab-out-of-bounds Write in hfs_asc2mac hfs C 73 416d 515d 0/1 upstream: reported C repro on 2022/11/26 02:11
upstream KASAN: slab-out-of-bounds Write in hfs_asc2mac hfs C error 161 497d 515d 22/26 fixed on 2023/02/24 13:50
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2023/03/04 14:28 22m bisect fix linux-4.14.y job log (0) log
2023/02/02 12:24 23m bisect fix linux-4.14.y job log (0) log

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in hfs_asc2mac+0x62a/0x680 fs/hfs/trans.c:133
Write of size 1 at addr ffff8880b36d63ce by task syz-executor725/7960

CPU: 0 PID: 7960 Comm: syz-executor725 Not tainted 4.14.302-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_store1_noabort+0x68/0x70 mm/kasan/report.c:432
 hfs_asc2mac+0x62a/0x680 fs/hfs/trans.c:133
 hfs_cat_build_key+0xbe/0x1a0 fs/hfs/catalog.c:28
 hfs_lookup+0x18c/0x2b0 fs/hfs/dir.c:31
 lookup_open+0x5c4/0x1750 fs/namei.c:3220
 do_last fs/namei.c:3334 [inline]
 path_openat+0x14bb/0x2970 fs/namei.c:3571
 do_filp_open+0x179/0x3c0 fs/namei.c:3605
 do_sys_open+0x296/0x410 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7fb4596f3219
RSP: 002b:00007ffd6ffc9d08 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffd6ffc9d18 RCX: 00007fb4596f3219
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 00007ffd6ffc9d10 R08: 00007ffd6ffc9d10 R09: 00007fb4596b0540
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 7960:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 hfs_find_init+0x91/0x220 fs/hfs/bfind.c:21
 hfs_lookup+0xea/0x2b0 fs/hfs/dir.c:28
 lookup_open+0x5c4/0x1750 fs/namei.c:3220
 do_last fs/namei.c:3334 [inline]
 path_openat+0x14bb/0x2970 fs/namei.c:3571
 do_filp_open+0x179/0x3c0 fs/namei.c:3605
 do_sys_open+0x296/0x410 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3

Freed by task 6118:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 aa_free_file_ctx security/apparmor/include/file.h:76 [inline]
 apparmor_file_free_security+0x7e/0xb0 security/apparmor/lsm.c:441
 security_file_free+0x42/0x80 security/security.c:879
 __fput+0x26c/0x7a0 fs/file_table.c:211
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3

The buggy address belongs to the object at ffff8880b36d6380
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 78 bytes inside of
 96-byte region [ffff8880b36d6380, ffff8880b36d63e0)
The buggy address belongs to the page:
page:ffffea0002cdb580 count:1 mapcount:0 mapping:ffff8880b36d6000 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff8880b36d6000 0000000000000000 0000000100000020
raw: ffffea0002cd4fa0 ffffea00026ec2a0 ffff88813fe744c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880b36d6280: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8880b36d6300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff8880b36d6380: 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc fc
                                              ^
 ffff8880b36d6400: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8880b36d6480: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/12/29 12:46 linux-4.14.y c4215ee4771b 44712fbc .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
2022/12/04 03:43 linux-4.14.y 179ef7fe8677 e080de16 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
2022/12/03 23:57 linux-4.14.y 179ef7fe8677 e080de16 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
2022/12/03 12:26 linux-4.14.y 179ef7fe8677 e080de16 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
2022/12/02 20:22 linux-4.14.y 179ef7fe8677 e080de16 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
2022/12/28 03:01 linux-4.14.y c4215ee4771b 44712fbc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
2022/12/28 02:42 linux-4.14.y c4215ee4771b 44712fbc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
2022/12/28 02:13 linux-4.14.y c4215ee4771b 44712fbc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
2022/12/22 03:47 linux-4.14.y c4215ee4771b 4067838e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 KASAN: slab-out-of-bounds Write in hfs_asc2mac
* Struck through repros no longer work on HEAD.