loop0: detected capacity change from 0 to 2048 EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue. Quota mode: none. Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 4423 Comm: syz-executor.0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025 pstate: 42400405 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=jc) pc : fault_in_readable+0x26c/0x354 mm/gup.c:1801 lr : fault_in_readable+0x248/0x354 mm/gup.c:1801 sp : ffff80001f2e7690 x29: ffff80001f2e76b0 x28: 0000002038b00000 x27: 000000002038c000 x26: 000000002038b000 x25: 000000002038b000 x24: 00000000fffffff2 x23: 1fffe0001b621368 x22: ffff0000db109b40 x21: 0000000000000000 x20: 000000002038b000 x19: dfff800000000000 x18: 0000000000000001 x17: 0000000000000000 x16: ffff800008733cd0 x15: 000000002038b000 x14: 0000000000ff0100 x13: 1ffff0000282e06b x12: 0000000000ff0100 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : 000000002038b000 x7 : ffff800008750e10 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001 x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000 Call trace: fault_in_readable+0x26c/0x354 mm/gup.c:1801 fault_in_iov_iter_readable+0x120/0x248 lib/iov_iter.c:460 generic_perform_write+0x330/0x480 mm/filemap.c:3775 ext4_buffered_write_iter+0x408/0x538 fs/ext4/file.c:268 ext4_file_write_iter+0x698/0x14cc include/linux/fs.h:-1 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x7c8/0xa2c fs/read_write.c:594 ksys_write+0x120/0x210 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:656 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 Code: 381f43b5 2a1503f8 2a1503e0 38400909 (381f43a9) ---[ end trace fc4d6571cdcc1cf2 ]--- ---------------- Code disassembly (best guess): 0: 381f43b5 sturb w21, [x29, #-12] 4: 2a1503f8 mov w24, w21 8: 2a1503e0 mov w0, w21 c: 38400909 ldtrb w9, [x8] * 10: 381f43a9 sturb w9, [x29, #-12] <-- trapping instruction