FYI, we noticed the following commit: commit: c55a9697e10aba9946692c56e9236993c1da023a ("Reimplement IDR and IDA using the radix tree") git://git.infradead.org/users/willy/linux-dax.git idr-2016-12-26 in testcase: trinity with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/ on test machine: qemu-system-x86_64 -enable-kvm -m 320M caused below changes: +-------------------------------------------+------------+------------+ | | ef9e389452 | c55a9697e1 | +-------------------------------------------+------------+------------+ | boot_successes | 0 | 0 | | boot_failures | 22 | 20 | | BUG:KASAN:use-after-free_in | 22 | | | calltrace:init | 20 | | | BUG:KASAN:null-ptr-deref_on_address(null) | 0 | 20 | | BUG:unable_to_handle_kernel | 0 | 20 | | Oops | 0 | 20 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 20 | +-------------------------------------------+------------+------------+ [ 16.646161] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input1 [ 16.654910] ACPI: Power Button [PWRF] [ 16.669533] ================================================================== [ 16.676428] BUG: KASAN: null-ptr-deref on address (null) [ 16.677900] Read of size 1 by task swapper/1 [ 16.679005] CPU: 0 PID: 1 Comm: swapper Not tainted 4.10.0-rc1-00012-gc55a969 #1 [ 16.680861] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014 [ 16.693066] Call Trace: [ 16.695546] show_stack+0x6b/0x6e [ 16.696466] dump_stack+0x19/0x1b [ 16.697400] kasan_report+0x171/0x559 To reproduce: git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email Thanks, Xiaolong