On 07/06/2020 08:27, kernel test robot wrote:
Greeting,
FYI, we noticed the following commit (built with gcc-9):
commit: 24256c140e59c3431af4918fd4ec892102cbc2f3 ("x86: mm: ptdump: calculate
effective permissions correctly")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
This was reported earlier[1] by Qian Cai and I posted a fix[2]. Linus'
tree has the fixed commit[3].
Steve
[1]
https://lore.kernel.org/lkml/20200522180741.GB1337@Qians-MacBook-Air.local/
[2]
https://lore.kernel.org/linux-mm/430c8ab4-e7cd-6933-dde6-087fac6db...@arm.com/
[3] 1494e0c38ee9 ("x86: mm: ptdump: calculate effective permissions
correctly")
in testcase: boot
on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G
caused below changes (please refer to attached dmesg/kmsg for entire
log/backtrace):
If you fix the issue, kindly add following tag
Reported-by: kernel test robot <rong.a.c...@intel.com>
[ 8.785395] UBSAN: array-index-out-of-bounds in
arch/x86/mm/dump_pagetables.c:285:27
[ 8.787718] index -1 is out of range for type 'pgprotval_t [5]'
[ 8.789278] CPU: 1 PID: 1 Comm: swapper/0 Not tainted
5.7.0-rc7-00027-g24256c140e59c #1
[ 8.791350] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.12.0-1 04/01/2014
[ 8.793505] Call Trace:
[ 8.794221] dump_stack+0x6c/0x94
[ 8.795140] ubsan_epilogue+0x8/0x3e
[ 8.796132] __ubsan_handle_out_of_bounds+0x48/0x53
[ 8.797362] ? is_visible+0x2b/0x32
[ 8.798231] ? atomic_try_cmpxchg+0x4c/0x57
[ 8.799203] note_page+0x37/0x80b
[ 8.800138] ? __up_read+0x352/0x37b
[ 8.801124] ptdump_walk_pgd+0x57/0x60
[ 8.802145] ptdump_walk_pgd_level_core+0x72/0x9f
[ 8.803369] ? ptdump_walk_pgd_level_debugfs+0x18/0x18
[ 8.804613] ? ptdump_walk_pgd_level_core+0x9f/0x9f
[ 8.805779] ptdump_walk_pgd_level_checkwx+0x1d/0x21
[ 8.806873] mark_rodata_ro+0x9f/0xa6
[ 8.807821] ? rest_init+0x7f/0x164
[ 8.808808] kernel_init+0x44/0xf7
[ 8.809735] ? rest_init+0x164/0x164
[ 8.810708] ret_from_fork+0x19/0x24
To reproduce:
# build kernel
cd linux
cp config-5.7.0-rc7-00027-g24256c140e59c .config
make HOSTCC=gcc-9 CC=gcc-9 ARCH=i386 olddefconfig prepare
modules_prepare bzImage
git clone https://github.com/intel/lkp-tests.git
cd lkp-tests
bin/lkp qemu -k <bzImage> job-script # job-script is attached in this
email
Thanks,
Rong Chen
