Mass Storage Function, version: 2009/09/11
LUN: removable file: (no medium)
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 4747 Comm: syz.2.82 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:fsg_common_set_num_buffers+0x5d/0x2b0 drivers/usb/gadget/function/f_mass_storage.c:2762
Code: a4 01 00 00 49 89 c6 49 bd 00 00 00 00 00 fc ff df bf 00 40 00 00 be c0 0c 00 00 e8 8d f4 2a fb 48 89 c3 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 a4 7c 43 fb 49 89 1e 48 85 db 0f
RSP: 0018:ffffc90005607b90 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff888055f38000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8adf6400 RDI: ffffffff8adf63c0
RBP: ffffc90005607ca0 R08: 0000000000004000 R09: ffffed100abe7800
R10: dffffc0000000000 R11: fffffbfff2162674 R12: ffff88807cb30800
R13: dffffc0000000000 R14: 0000000000000010 R15: 0000000000000000
FS:  00007fc7c4ff66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa560115000 CR3: 000000007ca32000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 fsg_opts_num_buffers_store+0x13a/0x1c0 drivers/usb/gadget/function/f_mass_storage.c:3456
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x30b/0x400 fs/configfs/file.c:229
 call_write_iter include/linux/fs.h:2271 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc7c6d9e159
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:00007fc7c4ff6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc7c7025fa0 RCX: 00007fc7c6d9e159
RDX: 0000000000000012 RSI: 0000200000000300 RDI: 0000000000000003
RBP: 00007fc7c6e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc7c7026038 R14: 00007fc7c7025fa0 R15: 00007ffcb6e11188
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:fsg_common_set_num_buffers+0x5d/0x2b0 drivers/usb/gadget/function/f_mass_storage.c:2762
Code: a4 01 00 00 49 89 c6 49 bd 00 00 00 00 00 fc ff df bf 00 40 00 00 be c0 0c 00 00 e8 8d f4 2a fb 48 89 c3 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 a4 7c 43 fb 49 89 1e 48 85 db 0f
RSP: 0018:ffffc90005607b90 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff888055f38000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8adf6400 RDI: ffffffff8adf63c0
RBP: ffffc90005607ca0 R08: 0000000000004000 R09: ffffed100abe7800
R10: dffffc0000000000 R11: fffffbfff2162674 R12: ffff88807cb30800
R13: dffffc0000000000 R14: 0000000000000010 R15: 0000000000000000
FS:  00007fc7c4ff66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa56944de79 CR3: 000000007ca32000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	00 00                	add    %al,(%rax)
   2:	49 89 c6             	mov    %rax,%r14
   5:	49 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%r13
   c:	fc ff df
   f:	bf 00 40 00 00       	mov    $0x4000,%edi
  14:	be c0 0c 00 00       	mov    $0xcc0,%esi
  19:	e8 8d f4 2a fb       	call   0xfb2af4ab
  1e:	48 89 c3             	mov    %rax,%rbx
  21:	4c 89 f0             	mov    %r14,%rax
  24:	48 c1 e8 03          	shr    $0x3,%rax
* 28:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2d:	74 08                	je     0x37
  2f:	4c 89 f7             	mov    %r14,%rdi
  32:	e8 a4 7c 43 fb       	call   0xfb437cdb
  37:	49 89 1e             	mov    %rbx,(%r14)
  3a:	48 85 db             	test   %rbx,%rbx
  3d:	0f                   	.byte 0xf