UBSAN: shift-out-of-bounds in ext4_check_opt

Date	Name	Commit	Repro	Result
2026/10/15	upstream (ToT)	0fcb05b72344	C	[report] lost connection to test machine

Date

Name

Commit

Repro

Result

2026/10/15

upstream (ToT)

0fcb05b72344

[report] lost connection to test machine

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
android-6-1	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency origin:lts	-1	syz, C		error	12	38d	305d	0/2	upstream: reported C repro on 2026/01/05 06:19

EXT4-fs error (device loop0) in ext4_process_orphan:345: Corrupt filesystem EXT4-fs (loop0): 1 truncate cleaned up EXT4-fs (loop0): mounted filesystem without journal. Quota mode: writeback. ================================================================================ UBSAN: shift-out-of-bounds in fs/ext4/super.c:2766:15 shift exponent 1987084706 is too large for 32-bit type 'int' CPU: 0 PID: 4479 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 ubsan_epilogue+0x14/0x48 lib/ubsan.c:151 __ubsan_handle_shift_out_of_bounds+0x2b0/0x348 lib/ubsan.c:321 ext4_check_opt_consistency+0x16d0/0x1afc fs/ext4/super.c:2766 ext4_reconfigure+0xac/0x2268 fs/ext4/super.c:6694 reconfigure_super+0x1d4/0x79c fs/super.c:977 do_remount fs/namespace.c:2741 [inline] path_mount+0xbdc/0xe80 fs/namespace.c:3400 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x49c/0x59c fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 ================================================================================ EXT4-fs: test_dummy_encryption requires encrypt feature

Crashes (4):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2026/04/19 17:53	linux-6.1.y	7c87defbd336	303e2802	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro #1 (clean fs)] [mounted in repro #2 (clean fs)] [mounted in repro #3 (clean fs)]	ci2-linux-6-1-kasan-arm64	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency
2026/04/19 17:13	linux-6.1.y	7c87defbd336	303e2802	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro #1 (clean fs)] [mounted in repro #2 (clean fs)] [mounted in repro #3 (clean fs)]	ci2-linux-6-1-kasan-arm64	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency
2026/04/19 16:32	linux-6.1.y	7c87defbd336	303e2802	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro #1 (clean fs)] [mounted in repro #2 (clean fs)] [mounted in repro #3 (clean fs)]	ci2-linux-6-1-kasan-arm64	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency
2026/04/19 15:50	linux-6.1.y	7c87defbd336	303e2802	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-linux-6-1-kasan-arm64	UBSAN: shift-out-of-bounds in ext4_check_opt_consistency

Crashes (4):

Assets (help?)