UBSAN: shift-out-of-bounds in __f2fs_commit_super

Status: upstream: reported C repro on 2026/09/24 05:00
Subsystems: f2fs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+dfcbc1741488709db4b2@syzkaller.appspotmail.com
First crash: 17d, last: 11h19m
Cause bisection: the cause commit could be any of (bisect log):
  48747bfe30c6 f2fs: describe xattr block layout dynamically
  b32d4bdbae61 f2fs: parameterize sector conversion macros
   
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
1fc0dff8 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ UBSAN: shift-out-of-bounds in __f2fs_commit_super 2026/09/24 01:23 2026/09/24 01:23 2026/09/24 02:03 0a1606bc
▶ ▼ Discussions (3)
Title Replies (including bot) Last reply
[PATCH] f2fs: fix to set sbi->log_blocksize in advance 1 (1) 2026/10/01 00:04
[syzbot] [f2fs?] UBSAN: shift-out-of-bounds in __f2fs_commit_super 1 (4) 2026/09/30 13:53
[PATCH] f2fs: check log_blocksize bounds in __f2fs_commit_super 1 (1) 2026/09/24 13:37
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2026/09/30 08:55 2h02m chao@kernel.org https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git bugfix/common no crash job log log
2026/09/24 12:22 26m nsvatoslav515@gmail.com patch https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master OK job log log

Sample crash report:
loop0: detected capacity change from 0 to 40427
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/f2fs/super.c:3950:27
shift exponent 4294967287 is too large for 64-bit type 'sector_t' (aka 'unsigned long long')
CPU: 1 UID: 0 PID: 5622 Comm: syz-executor329 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
 __ubsan_handle_shift_out_of_bounds+0x36d/0x400 lib/ubsan.c:494
 __f2fs_commit_super+0x43e/0x4d0 fs/f2fs/super.c:3950
 sanity_check_area_boundary+0x7c5/0xe20 fs/f2fs/super.c:4040
 sanity_check_raw_super fs/f2fs/super.c:4215 [inline]
 read_raw_super_block fs/f2fs/super.c:4625 [inline]
 f2fs_fill_super+0x1920/0x7fa0 fs/f2fs/super.c:5160
 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1872
 vfs_get_tree+0x92/0x2a0 fs/super.c:1932
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3772 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3848
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4394 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4371
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2eb02deeaa
Code: 56 53 b8 9d 00 00 00 0f 05 83 f8 ea 75 a2 c7 05 e4 5b 09 00 00 00 00 00 eb 96 e8 51 05 00 00 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcaf01ba78 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcaf01ba90 RCX: 00007f2eb02deeaa
RDX: 0000200000000080 RSI: 0000200000000000 RDI: 00007ffcaf01ba90
RBP: 0000200000000000 R08: 00007ffcaf01bad0 R09: 0000000000000000
R10: 0000000000200000 R11: 0000000000000286 R12: 0000200000000080
R13: 00007ffcaf01bad0 R14: 0000000000000003 R15: 0000000000200000
 </TASK>
---[ end trace ]---

Crashes (100):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/23 03:33 linux-next a8c591ed6b67 3e2106e5 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/23 03:09 linux-next a8c591ed6b67 3e2106e5 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/09 21:46 linux-next aac26bee2287 a8add9cd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/08 18:54 linux-next b01868671970 4f6a9fcf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/08 08:00 linux-next b01868671970 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/07 20:44 linux-next b01868671970 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/07 09:49 linux-next eea3fef32a9c f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/07 08:43 linux-next eea3fef32a9c f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/06 19:11 linux-next eea3fef32a9c f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/06 01:22 linux-next bf1ee2bd5c2d 1995e6c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/05 21:49 linux-next bf1ee2bd5c2d 1995e6c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/04 13:01 linux-next f0406245cb98 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/04 01:47 linux-next f0406245cb98 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/02 23:12 linux-next 9f24d789f03b 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/02 20:25 linux-next 9f24d789f03b 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/10/02 06:33 linux-next 9f24d789f03b 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/30 21:16 linux-next 6c2cb8b8b843 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/30 09:32 linux-next 6474fa070f2b 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/30 09:29 linux-next 6474fa070f2b 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/29 16:31 linux-next 6375e61c01e9 7bf4ea23 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/29 08:28 linux-next 6375e61c01e9 7bf4ea23 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/29 06:05 linux-next 6375e61c01e9 7bf4ea23 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/28 22:19 linux-next 6375e61c01e9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/28 20:24 linux-next 6375e61c01e9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/28 10:45 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/27 22:34 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/27 22:29 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/27 10:48 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/27 08:25 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/27 08:24 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/26 16:11 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/26 16:11 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/26 16:11 linux-next f5f84daefcd9 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/26 03:33 linux-next f5f84daefcd9 f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/26 03:33 linux-next f5f84daefcd9 f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/25 22:11 linux-next f5f84daefcd9 f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 18:01 linux-next 3d7783543c26 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 15:43 linux-next 3d7783543c26 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 15:43 linux-next 3d7783543c26 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 03:44 linux-next a8c591ed6b67 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 03:41 linux-next a8c591ed6b67 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 03:40 linux-next a8c591ed6b67 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 03:38 linux-next a8c591ed6b67 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 03:38 linux-next a8c591ed6b67 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/24 03:38 linux-next a8c591ed6b67 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/23 12:51 linux-next a8c591ed6b67 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
2026/09/23 12:51 linux-next a8c591ed6b67 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root UBSAN: shift-out-of-bounds in __f2fs_commit_super
* Struck through repros no longer work on HEAD.