UBSAN: shift-out-of-bounds in extAlloc

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	UBSAN: shift-out-of-bounds in extAlloc jfs	-1	C	error		6605	845d	1205d	23/29	fixed on 2023/10/12 12:47
linux-5.15	UBSAN: shift-out-of-bounds in extAlloc (2) origin:upstream	-1	C		error	1	57d	244d	0/3	upstream: reported C repro on 2025/05/14 03:45
linux-5.15	UBSAN: shift-out-of-bounds in extAlloc origin:upstream	-1	C		done	217	849d	1041d	3/3	fixed on 2023/10/20 00:28
linux-6.1	UBSAN: shift-out-of-bounds in extAlloc origin:upstream missing-backport	-1	C		done	204	274d	1037d	3/3	fixed on 2025/05/02 07:04
upstream	UBSAN: shift-out-of-bounds in extAlloc (2) jfs	-1	C	inconclusive		11	13d	620d	0/29	upstream: reported C repro on 2024/05/03 13:40

================================================================================ UBSAN: shift-out-of-bounds in fs/jfs/jfs_extent.c:319:16 shift exponent 94 is too large for 64-bit type 's64' (aka 'long long') CPU: 0 PID: 6093 Comm: syz.2.52 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: <TASK> dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 ubsan_epilogue+0xa/0x30 lib/ubsan.c:217 __ubsan_handle_shift_out_of_bounds+0x380/0x400 lib/ubsan.c:387 extBalloc fs/jfs/jfs_extent.c:319 [inline] extAlloc+0xcbf/0xf30 fs/jfs/jfs_extent.c:122 jfs_get_block+0x347/0xab0 fs/jfs/inode.c:254 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124 __block_write_begin fs/buffer.c:2173 [inline] block_write_begin+0x9a/0x1e0 fs/buffer.c:2234 jfs_write_begin+0x35/0x70 fs/jfs/inode.c:305 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152 __kernel_write_iter+0x274/0x670 fs/read_write.c:517 dump_emit_page fs/coredump.c:957 [inline] dump_user_range+0x3f6/0x800 fs/coredump.c:984 elf_core_dump+0x3114/0x36e0 fs/binfmt_elf.c:2184 do_coredump+0x1755/0x2480 fs/coredump.c:833 get_signal+0x1133/0x1400 kernel/signal.c:2888 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 exc_page_fault+0x8f/0x110 arch/x86/mm/fault.c:1524 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fa95e78f751 Code: 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:fffffffffffffe70 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007fa95e9e5fa0 RCX: 00007fa95e78f749 RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000 RBP: 00007fa95e813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa95e9e6038 R14: 00007fa95e9e5fa0 R15: 00007fffcb892028 </TASK> ================================================================================

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2026/01/08 15:13	linux-6.6.y	5fa4793a2d2d	d6526ea3	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-linux-6-6-kasan	UBSAN: shift-out-of-bounds in extAlloc

Crashes (1):

Assets (help?)