task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x100/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f ------------[ cut here ]------------ kernel BUG at mm/filemap.c:859! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 3 UID: 0 PID: 5883 Comm: syz.0.1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:__filemap_add_folio+0xf81/0x1350 mm/filemap.c:859 Code: 45 a5 c3 ff 48 8d 3d be e8 96 0e 67 48 0f b9 3a e9 07 fd ff ff e8 2f a5 c3 ff 48 c7 c6 20 56 bd 8b 4c 89 ef e8 a0 bb 12 00 90 <0f> 0b 4c 8b 6c 24 60 e8 13 a5 c3 ff 48 c7 84 24 a0 00 00 00 03 00 RSP: 0018:ffffc90004b073e0 EFLAGS: 00010246 RAX: 0000000000080000 RBX: 0000000000000000 RCX: ffffc900074a2000 RDX: 0000000000080000 RSI: ffffffff8257a2e8 RDI: ffff88802ec729c4 RBP: 0000000000112cc0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000003 R12: 0000000000000002 R13: ffffea000170e580 R14: 0000000000000000 R15: 1ffff92000960ea7 FS: 00007f4f001ee6c0(0000) GS:ffff8880d6676000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000073d000 CR3: 0000000034d55000 CR4: 0000000000352ef0 Call Trace: filemap_add_folio+0x1d8/0x690 mm/filemap.c:967 ra_alloc_folio mm/readahead.c:456 [inline] page_cache_ra_order+0x614/0xf10 mm/readahead.c:515 do_sync_mmap_readahead mm/filemap.c:3406 [inline] filemap_fault+0x1900/0x2e90 mm/filemap.c:3555 __do_fault+0x10b/0x440 mm/memory.c:5458 do_shared_fault mm/memory.c:5957 [inline] do_fault+0x2db/0x1750 mm/memory.c:6031 do_pte_missing mm/memory.c:4550 [inline] handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6549 handle_mm_fault+0x36d/0xa20 mm/memory.c:6718 do_user_addr_fault+0x74c/0x12f0 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] RIP: 0010:raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] RIP: 0010:copy_to_user_iter lib/iov_iter.c:25 [inline] RIP: 0010:iterate_ubuf include/linux/iov_iter.h:30 [inline] RIP: 0010:iterate_and_advance2 include/linux/iov_iter.h:302 [inline] RIP: 0010:iterate_and_advance include/linux/iov_iter.h:330 [inline] RIP: 0010:_copy_to_iter+0x38c/0x1720 lib/iov_iter.c:197 Code: 00 00 00 00 e9 4d ff ff ff e8 90 8c 11 fd 4c 8b 74 24 18 44 89 fe 4c 89 f7 e8 10 4a 7f fd 0f 01 cb 4c 89 f9 48 89 df 4c 89 f6 a4 0f 1f 00 48 89 cb 0f 01 ca 4c 89 f8 48 29 c8 48 89 44 24 08 RSP: 0018:ffffc90004b07bb8 EFLAGS: 00050246 RAX: 0000000000000001 RBX: 000020000073d000 RCX: 0000000000000040 RDX: 0000000000000001 RSI: ffffc90004b07d78 RDI: 000020000073d000 RBP: ffffc90004b07e68 R08: 0000000000000000 R09: fffff52000960fb6 R10: ffffc90004b07db7 R11: 0000000000000000 R12: 000020000073d040 R13: 00007ffffffff000 R14: ffffc90004b07d78 R15: 0000000000000040 copy_to_iter include/linux/uio.h:220 [inline] get_random_bytes_user+0x17b/0x3d0 drivers/char/random.c:462 __do_sys_getrandom drivers/char/random.c:1406 [inline] __se_sys_getrandom drivers/char/random.c:1380 [inline] __x64_sys_getrandom+0x183/0x290 drivers/char/random.c:1380 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4f01f9cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4f001ee028 EFLAGS: 00000246 ORIG_RAX: 000000000000013e RAX: ffffffffffffffda RBX: 00007f4f02215fa0 RCX: 00007f4f01f9cdd9 RDX: 0000000000000000 RSI: 00000000ffffff9a RDI: 0000200000000240 RBP: 00007f4f02032d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4f02216038 R14: 00007f4f02215fa0 R15: 00007ffd84ae2108 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__filemap_add_folio+0xf81/0x1350 mm/filemap.c:859 Code: 45 a5 c3 ff 48 8d 3d be e8 96 0e 67 48 0f b9 3a e9 07 fd ff ff e8 2f a5 c3 ff 48 c7 c6 20 56 bd 8b 4c 89 ef e8 a0 bb 12 00 90 <0f> 0b 4c 8b 6c 24 60 e8 13 a5 c3 ff 48 c7 84 24 a0 00 00 00 03 00 RSP: 0018:ffffc90004b073e0 EFLAGS: 00010246 RAX: 0000000000080000 RBX: 0000000000000000 RCX: ffffc900074a2000 RDX: 0000000000080000 RSI: ffffffff8257a2e8 RDI: ffff88802ec729c4 RBP: 0000000000112cc0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000003 R12: 0000000000000002 R13: ffffea000170e580 R14: 0000000000000000 R15: 1ffff92000960ea7 FS: 00007f4f001ee6c0(0000) GS:ffff8880d6676000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000073d000 CR3: 0000000034d55000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: e9 4d ff ff ff jmp 0xffffff56 9: e8 90 8c 11 fd call 0xfd118c9e e: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 13: 44 89 fe mov %r15d,%esi 16: 4c 89 f7 mov %r14,%rdi 19: e8 10 4a 7f fd call 0xfd7f4a2e 1e: 0f 01 cb stac 21: 4c 89 f9 mov %r15,%rcx 24: 48 89 df mov %rbx,%rdi 27: 4c 89 f6 mov %r14,%rsi * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 0f 1f 00 nopl (%rax) 2f: 48 89 cb mov %rcx,%rbx 32: 0f 01 ca clac 35: 4c 89 f8 mov %r15,%rax 38: 48 29 c8 sub %rcx,%rax 3b: 48 89 44 24 08 mov %rax,0x8(%rsp)