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BUG: KMSAN: uninit-value in do_error_trap+0x39b/0x600 arch/x86/kernel/traps.c:297
CPU: 0 PID: 3648 Comm: syz-executor0 Not tainted 4.16.0+ #84
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
 do_error_trap+0x39b/0x600 arch/x86/kernel/traps.c:297
 do_invalid_op+0x46/0x50 arch/x86/kernel/traps.c:316
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986
RIP: 0010:notify_change+0x1e1/0x1b00 fs/attr.c:213
RSP: 0018:ffff8801b8adf8d0 EFLAGS: 00010293
RAX: ffffffff81dd7451 RBX: ffff8801dc840690 RCX: ffff8801b9e10000
RDX: 0000000000000000 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffff8801b8adf9b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8801b9e10918 R14: 0000000000000000 R15: 0000000000004200
 __remove_privs fs/inode.c:1809 [inline]
 file_remove_privs+0x67a/0x830 fs/inode.c:1831
 __generic_file_write_iter+0x1d7/0x990 mm/filemap.c:3209
 blkdev_write_iter+0x3a8/0x5f0 fs/block_dev.c:1908
 call_write_iter include/linux/fs.h:1782 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x719/0x910 fs/read_write.c:482
 vfs_write+0x463/0x8d0 fs/read_write.c:544
 SYSC_write+0x172/0x360 fs/read_write.c:589
 SyS_write+0x55/0x80 fs/read_write.c:581
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455329
RSP: 002b:00007fe1834a8c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe1834a96d4 RCX: 0000000000455329
RDX: 0000000000000003 RSI: 0000000020000b80 RDI: 0000000000000004
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000006bd R14: 00000000006fd258 R15: 0000000000000000

Local variable description: ----info64.i@lo_ioctl
Variable was created at:
 lo_ioctl+0x10c/0x41e0 drivers/block/loop.c:1351
 __blkdev_driver_ioctl block/ioctl.c:303 [inline]
 blkdev_ioctl+0xc62/0x4e10 block/ioctl.c:601
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