]> git.baikalelectronics.ru Git - kernel.git/commit
kvm: properly check debugfs dentry before using it
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 28 Feb 2019 15:34:37 +0000 (16:34 +0100)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 28 Feb 2019 16:57:32 +0000 (08:57 -0800)
commitec1076ddae4bf3dd5544baa485b6ccb1ff4709c3
treeea32630d2ee0fa5cadc0ecad0de1869ee9d64dcb
parent71a60313a50d2da8cf616376eec8441e890b4cfb
kvm: properly check debugfs dentry before using it

debugfs can now report an error code if something went wrong instead of
just NULL.  So if the return value is to be used as a "real" dentry, it
needs to be checked if it is an error before dereferencing it.

This is now happening because of 846632d286c9 ("debugfs: return error
values, not NULL").  syzbot has found a way to trigger multiple debugfs
files attempting to be created, which fails, and then the error code
gets passed to dentry_path_raw() which obviously does not like it.

Reported-by: Eric Biggers <ebiggers@kernel.org>
Reported-and-tested-by: syzbot+7857962b4d45e602b8ad@syzkaller.appspotmail.com
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
virt/kvm/kvm_main.c