UBSAN: shift-out-of-bounds in ext4_check_opt

Date	Name	Commit	Repro	Result
2026/01/06	lts (merge base)	f6e38ae624cf	C	[report] UBSAN: shift-out-of-bounds in ext4_check_opt_consistency
2026/01/06	upstream (ToT)	7f98ab9da046	C	Didn't crash

Date

Name

Commit

Repro

Result

2026/01/06

lts (merge base)

f6e38ae624cf

[report] UBSAN: shift-out-of-bounds in ext4_check_opt_consistency

2026/01/06

upstream (ToT)

7f98ab9da046

Didn't crash


Created	Duration	User	Repo	Result
2026/01/22 02:40	6m	retest repro	android14-6.1	report log
2026/01/22 02:40	6m	retest repro	android14-6.1	report log
2026/01/22 02:40	6m	retest repro	android14-6.1	report log

EXT4-fs (loop2): mounted filesystem without journal. Quota mode: none. EXT4-fs: Ignoring removed mblk_io_submit option ================================================================================ UBSAN: shift-out-of-bounds in fs/ext4/super.c:2704:15 shift exponent 808464432 is too large for 32-bit type 'int' CPU: 0 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: <TASK> __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 dump_stack+0x15/0x24 lib/dump_stack.c:113 ubsan_epilogue+0xe/0x40 lib/ubsan.c:151 __ubsan_handle_shift_out_of_bounds+0x37c/0x400 lib/ubsan.c:321 ext4_check_opt_consistency+0x138d/0x1720 fs/ext4/super.c:2704 ext4_reconfigure+0xc7/0x2800 fs/ext4/super.c:6649 reconfigure_super+0x228/0x890 fs/super.c:979 do_remount fs/namespace.c:2741 [inline] path_mount+0xdea/0x1010 fs/namespace.c:3400 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3606 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3606 x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2bbe190eea Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd1859d908 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007ffd1859d990 RCX: 00007f2bbe190eea RDX: 0000200000000180 RSI: 0000200000000000 RDI: 0000000000000000 RBP: 0000200000000180 R08: 00007ffd1859d990 R09: 0000000001b7a434 R10: 0000000001b7a434 R11: 0000000000000246 R12: 0000200000000000 R13: 00007ffd1859d950 R14: 0000000000000000 R15: 00002000000003c0 </TASK> ================================================================================

Crashes (4):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2026/01/05 07:07	android14-6.1	5e6db7045704	d6526ea3	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)]	ci2-android-6-1	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency
2026/01/05 06:38	android14-6.1	5e6db7045704	d6526ea3	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)]	ci2-android-6-1	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency
2026/01/05 06:09	android14-6.1	5e6db7045704	d6526ea3	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)]	ci2-android-6-1	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency
2026/01/05 05:37	android14-6.1	5e6db7045704	d6526ea3	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-android-6-1	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency

Crashes (4):

Assets (help?)