UBSAN: shift-out-of-bounds in exfat_fill

Date	Name	Commit	Repro	Result
2025/09/27	linux-5.15.y (ToT)	43bb85222e53	C	[report] UBSAN: shift-out-of-bounds in exfat_fill_super
2025/09/27	upstream (ToT)	fec734e8d564	C	Didn't crash

Date

Name

Commit

Repro

Result

2025/09/27

linux-5.15.y (ToT)

43bb85222e53

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

2025/09/27

upstream (ToT)

fec734e8d564

Didn't crash

Kernel	Title	Rank 🛈	Repro	Cause bisect	Count	Last	Reported	Patched	Status
upstream	UBSAN: shift-out-of-bounds in exfat_fill_super (2) exfat	-1			1	692d	688d	0/29	auto-obsoleted due to no activity on 2024/02/22 05:01
upstream	UBSAN: shift-out-of-bounds in exfat_fill_super exfat	-1	C	error	3	1698d	1715d	20/29	fixed on 2021/04/09 19:46
linux-5.15	UBSAN: shift-out-of-bounds in exfat_fill_super	-1			1	115d	115d	0/3	auto-obsoleted due to no activity on 2025/09/21 09:33
android-5-15	UBSAN: shift-out-of-bounds in exfat_fill_super origin:lts	-1	C		8	2d15h	129d	0/2	upstream: reported C repro on 2025/05/30 13:08
android-6-1	UBSAN: shift-out-of-bounds in exfat_fill_super origin:upstream	-1	C		3	13d	173d	0/2	upstream: reported C repro on 2025/04/16 14:18

exFAT-fs (loop0): Volume was not properly unmounted. Some data may be corrupt. Please run fsck. exFAT-fs (loop0): Medium has reported failures. Some data may be lost. ================================================================================ UBSAN: shift-out-of-bounds in fs/exfat/super.c:520:38 shift exponent 116 is too large for 32-bit type 'int' CPU: 1 PID: 4347 Comm: syz.0.24 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: <TASK> dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 ubsan_epilogue+0xa/0x30 lib/ubsan.c:151 __ubsan_handle_shift_out_of_bounds+0x37c/0x400 lib/ubsan.c:321 exfat_read_boot_sector fs/exfat/super.c:520 [inline] __exfat_fill_super fs/exfat/super.c:576 [inline] exfat_fill_super+0x2943/0x2cf0 fs/exfat/super.c:644 get_tree_bdev+0x3f1/0x610 fs/super.c:1325 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3025 do_mount fs/namespace.c:3368 [inline] __do_sys_mount fs/namespace.c:3576 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3553 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f85a7b223ca 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:00007f85a718fe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f85a718fef0 RCX: 00007f85a7b223ca RDX: 00002000000005c0 RSI: 0000200000000240 RDI: 00007f85a718feb0 RBP: 00002000000005c0 R08: 00007f85a718fef0 R09: 0000000003800052 R10: 0000000003800052 R11: 0000000000000246 R12: 0000200000000240 R13: 00007f85a718feb0 R14: 00000000000014fe R15: 0000200000000600 </TASK> ================================================================================

Crashes (3):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2025/09/21 20:27	linux-5.15.y	43bb85222e53	67c37560	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)]	ci2-linux-5-15-kasan	UBSAN: shift-out-of-bounds in exfat_fill_super
2025/09/21 19:39	linux-5.15.y	43bb85222e53	67c37560	.config	console log	report	syz / log	C		[disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)]	ci2-linux-5-15-kasan	UBSAN: shift-out-of-bounds in exfat_fill_super
2025/09/21 18:11	linux-5.15.y	43bb85222e53	67c37560	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan	UBSAN: shift-out-of-bounds in exfat_fill_super

Crashes (3):

Assets (help?)