drm_stub_open+0x20f/0x380 drivers/gpu/drm/drm_drv.c:1205 chrdev_open+0x234/0x6a0 fs/char_dev.c:414 do_dentry_open+0x982/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4134 ------------[ cut here ]------------ kernel BUG at mm/filemap.c:870! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 14247 Comm: syz.5.2360 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:__filemap_add_folio+0xf5b/0x11e0 mm/filemap.c:870 Code: 52 c7 ff 48 c7 c6 60 70 99 8b 4c 89 ef e8 bd 6b 11 00 90 0f 0b e8 e5 52 c7 ff 48 c7 c6 c0 70 99 8b 4c 89 ef e8 a6 6b 11 00 90 <0f> 0b e8 ce 52 c7 ff 90 0f 0b 90 e9 f2 fb ff ff e8 c0 52 c7 ff 48 RSP: 0018:ffffc9000375f4f8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880487d2480 RSI: ffffffff81f5baca RDI: ffff8880487d2904 RBP: 0000000000112cc0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff908204d7 R11: 0000000000000002 R12: 0000000000000002 R13: ffffea0001572640 R14: 0000000000000000 R15: 1ffff920006ebec9 FS: 00007f96dcbf66c0(0000) GS:ffff8880d6b08000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000040 CR3: 0000000058959000 CR4: 0000000000352ef0 Call Trace: filemap_add_folio+0x19a/0x610 mm/filemap.c:978 ra_alloc_folio mm/readahead.c:453 [inline] page_cache_ra_order+0x635/0xf20 mm/readahead.c:512 do_sync_mmap_readahead mm/filemap.c:3340 [inline] filemap_fault+0x1583/0x29a0 mm/filemap.c:3489 __do_fault+0x10d/0x490 mm/memory.c:5280 do_read_fault mm/memory.c:5698 [inline] do_fault mm/memory.c:5832 [inline] do_pte_missing+0xf4a/0x3ba0 mm/memory.c:4361 handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault+0x1556/0x2aa0 mm/memory.c:6318 handle_mm_fault+0x589/0xd10 mm/memory.c:6487 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0x147/0x2e0 lib/strncpy_from_user.c:130 Code: 00 00 4d 89 74 1d 00 48 83 ed 08 bf 07 00 00 00 48 83 c3 08 48 89 ee e8 c7 98 e4 fc 48 83 fd 07 76 22 e8 4c 9d e4 fc 45 31 ff <49> 8b 04 1c 31 ff 44 89 fe 49 89 c6 e8 78 98 e4 fc 45 85 ff 0f 84 RSP: 0018:ffffc9000375fd00 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff84d86fb6 RDX: ffff8880487d2480 RSI: ffffffff84d87054 RDI: 0000000000000007 RBP: 0000000000000fe0 R08: 0000000000000007 R09: 0000000000000007 R10: 0000000000000fe0 R11: 0000000000000000 R12: 0000200000000300 R13: ffff88803bf66620 R14: 0000000000000fe0 R15: 0000000000000000 getname_flags.part.0+0x8f/0x550 fs/namei.c:157 getname_flags+0x93/0xf0 include/linux/audit.h:345 getname include/linux/fs.h:2922 [inline] do_sys_openat2+0xb8/0x1d0 fs/open.c:1431 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f96de98f6c9 Code: ff ff c3 66 2e 0f 1f 84 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 RSP: 002b:00007f96dcbf6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f96debe6090 RCX: 00007f96de98f6c9 RDX: 0000000000042000 RSI: 0000200000000300 RDI: ffffffffffffff9c RBP: 00007f96dea11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f96debe6128 R14: 00007f96debe6090 R15: 00007ffc580bddc8 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__filemap_add_folio+0xf5b/0x11e0 mm/filemap.c:870 Code: 52 c7 ff 48 c7 c6 60 70 99 8b 4c 89 ef e8 bd 6b 11 00 90 0f 0b e8 e5 52 c7 ff 48 c7 c6 c0 70 99 8b 4c 89 ef e8 a6 6b 11 00 90 <0f> 0b e8 ce 52 c7 ff 90 0f 0b 90 e9 f2 fb ff ff e8 c0 52 c7 ff 48 RSP: 0018:ffffc9000375f4f8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880487d2480 RSI: ffffffff81f5baca RDI: ffff8880487d2904 RBP: 0000000000112cc0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff908204d7 R11: 0000000000000002 R12: 0000000000000002 R13: ffffea0001572640 R14: 0000000000000000 R15: 1ffff920006ebec9 FS: 00007f96dcbf66c0(0000) GS:ffff8880d6b08000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000040 CR3: 0000000058959000 CR4: 0000000000352ef0 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 4d 89 74 1d 00 mov %r14,0x0(%r13,%rbx,1) 7: 48 83 ed 08 sub $0x8,%rbp b: bf 07 00 00 00 mov $0x7,%edi 10: 48 83 c3 08 add $0x8,%rbx 14: 48 89 ee mov %rbp,%rsi 17: e8 c7 98 e4 fc call 0xfce498e3 1c: 48 83 fd 07 cmp $0x7,%rbp 20: 76 22 jbe 0x44 22: e8 4c 9d e4 fc call 0xfce49d73 27: 45 31 ff xor %r15d,%r15d * 2a: 49 8b 04 1c mov (%r12,%rbx,1),%rax <-- trapping instruction 2e: 31 ff xor %edi,%edi 30: 44 89 fe mov %r15d,%esi 33: 49 89 c6 mov %rax,%r14 36: e8 78 98 e4 fc call 0xfce498b3 3b: 45 85 ff test %r15d,%r15d 3e: 0f .byte 0xf 3f: 84 .byte 0x84