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: 1d17h, last: 6h47m
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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
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Title Replies (including bot) Last reply
[syzbot] [f2fs?] UBSAN: shift-out-of-bounds in __f2fs_commit_super 0 (1) 2026/09/24 05:00

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 (26):
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
2026/09/24 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
2026/09/23 08:25 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 08:25 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 08:24 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 08:24 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 08:21 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 08:21 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 08:20 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 08:20 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 02:50 linux-next a8c591ed6b67 3e2106e5 .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 02:41 linux-next a8c591ed6b67 3e2106e5 .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 01:04 linux-next a8c591ed6b67 3e2106e5 .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
2026/09/22 23:24 linux-next a8c591ed6b67 3e2106e5 .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
2026/09/22 23:24 linux-next a8c591ed6b67 3e2106e5 .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
2026/09/22 23:21 linux-next a8c591ed6b67 3e2106e5 .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
2026/09/22 17:32 linux-next a8c591ed6b67 3e2106e5 .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
2026/09/22 17:31 linux-next a8c591ed6b67 3e2106e5 .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.