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UBSAN: array-index-out-of-bounds in dtSplitRoot

Status: upstream: reported C repro on 2022/10/15 19:21
Subsystems: jfs
[Documentation on labels]
Reported-by: syzbot+d4b1df2e9d4ded6488ec@syzkaller.appspotmail.com
Fix commit: UBSAN: array-index-out-of-bounds in dtSplitRoot
Patched on: [ci-upstream-linux-next-kasan-gce-root], missing on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce ci-upstream-kmsan-gce-386 ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 420d, last: 91d
Cause bisection: failed (error log, bisect log)
  
Fix bisection: the issue occurs on the latest tested release (bisect log)
  
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] UBSAN: array-index-out-of-bounds in dtSplitRoot 2 (2) 2023/11/01 14:46
[syzbot] UBSAN: array-index-out-of-bounds in dtSplitRoot 0 (1) 2022/10/15 19:21
▶ ▼ Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 KASAN: slab-out-of-bounds Read in dtSplitRoot C error 1 420d 420d 0/1 upstream: reported C repro on 2022/10/14 11:28
linux-4.14 KASAN: slab-out-of-bounds Read in dtSplitRoot C 1 284d 418d 0/1 upstream: reported C repro on 2022/10/15 22:33
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2023/10/13 16:36 15m osmtendev@gmail.com patch upstream OK log
2023/10/13 06:18 39m osmtendev@gmail.com patch upstream OK log
2023/10/13 05:30 14m osmtendev@gmail.com patch upstream report log
2023/09/08 17:02 9m retest repro upstream report log
▶ ▼ Fix bisection attempts (7)
Created Duration User Patch Repo Result
2023/06/30 14:51 51m bisect fix upstream job log (0)
2023/05/31 06:20 43m bisect fix upstream job log (0) log
2023/04/27 00:51 43m bisect fix upstream job log (0) log
2023/03/28 00:07 42m bisect fix upstream job log (0) log
2023/02/25 20:29 49m bisect fix upstream job log (0) log
2023/01/25 10:09 39m bisect fix upstream job log (0) log
2022/11/13 10:41 32m bisect fix upstream job log (0) log

Sample crash report:
loop0: detected capacity change from 0 to 32768
================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:1971:9
index -2 is out of range for type 'struct dtslot [128]'
CPU: 0 PID: 3613 Comm: syz-executor270 Not tainted 6.0.0-syzkaller-09423-g493ffd6605b2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
 ubsan_epilogue lib/ubsan.c:151 [inline]
 __ubsan_handle_out_of_bounds+0xdb/0x130 lib/ubsan.c:283
 dtSplitRoot+0x8d8/0x1900 fs/jfs/jfs_dtree.c:1971
 dtSplitUp fs/jfs/jfs_dtree.c:985 [inline]
 dtInsert+0x1189/0x6b80 fs/jfs/jfs_dtree.c:863
 jfs_mkdir+0x757/0xb00 fs/jfs/namei.c:270
 vfs_mkdir+0x3b3/0x590 fs/namei.c:4013
 do_mkdirat+0x279/0x550 fs/namei.c:4038
 __do_sys_mkdirat fs/namei.c:4053 [inline]
 __se_sys_mkdirat fs/namei.c:4051 [inline]
 __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4051
 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: 0033:0x7fcdc0113fd9
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:00007ffeb8bc67d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcdc0113fd9
RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000003
RBP: 00007fcdc00d37a0 R08: 0000000000000000 R09: 00007fcdc00d37a0
R10: 00005555559a72c0 R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00083878000000f8 R15: 0000000000000000
 </TASK>
================================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/10/14 10:40 upstream 493ffd6605b2 4954e4b2 .config strace log report syz C [disk image] [vmlinux] [mounted in repro] ci2-upstream-fs UBSAN: array-index-out-of-bounds in dtSplitRoot
2022/10/14 10:12 upstream 493ffd6605b2 4954e4b2 .config console log report info [disk image] [vmlinux] ci2-upstream-fs UBSAN: array-index-out-of-bounds in dtSplitRoot
* Struck through repros no longer work on HEAD.