BUG: unable to handle page fault for address: fe80c000 - EIP: memcpy+0xf/0x20

From: Naresh Kamboju
Date: Wed Aug 12 2020 - 09:22:09 EST


While testng LTP CVE cve-2017-17053 test case the kernel BUG triggered
on qemu_i386.
Not easily reproducible BUG.

metadata:
git branch: master
git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git commit: 4c9b89d8981be3b9032f94d0c4dc7eb9c7967a32
git describe: next-20200811
make_kernelversion: 5.8.0
kernel-config:
https://builds.tuxbuild.com/Y9BHRF7J_qXysFPxUoVmBA/kernel.config


[ 1083.853006] BUG: unable to handle page fault for address: fe80c000
[ 1083.853850] #PF: supervisor write access in kernel mode
[ 1083.854577] #PF: error_code(0x0002) - not-present page
[ 1083.855074] *pde = 33183067 *pte = a8648163
[ 1083.855074] Oops: 0002 [#1] SMP
[ 1083.855951] CPU: 1 PID: 13514 Comm: cve-2017-17053 Tainted: G
W 5.8.0-next-20200811 #1
[ 1083.857088] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.12.0-1 04/01/2014
[ 1083.857771] EIP: memcpy+0xf/0x20
[ 1083.857771] Code: 68 d0 7d ee d6 e8 11 1c c7 ff 0f 31 31 c3 59 58
eb 80 cc cc cc cc cc cc cc cc cc 55 89 e5 57 89 c7 56 89 d6 53 89 cb
c1 e9 02 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 5b 5e 5f 5d c3 90 55 89 e5
57 89
[ 1083.860096] EAX: fe80c000 EBX: 00010000 ECX: 00004000 EDX: fbfbd000
[ 1083.860096] ESI: fbfbd000 EDI: fe80c000 EBP: f11f1e2c ESP: f11f1e20
[ 1083.860096] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010216
[ 1083.860096] CR0: 80050033 CR2: fe80c000 CR3: 314c0000 CR4: 003506d0
[ 1083.860096] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 1083.860096] DR6: ffff4ff0 DR7: 00000400
[ 1083.860096] Call Trace:
[ 1083.860096] ldt_dup_context+0x66/0x80
[ 1083.860096] dup_mm+0x2b3/0x480
[ 1083.866900] copy_process+0x133b/0x15c0
[ 1083.866900] _do_fork+0x94/0x3e0
[ 1083.866900] __ia32_sys_clone+0x67/0x80
[ 1083.866900] __do_fast_syscall_32+0x3f/0x70
[ 1083.866900] do_fast_syscall_32+0x29/0x60
[ 1083.866900] do_SYSENTER_32+0x15/0x20
[ 1083.866900] entry_SYSENTER_32+0x9f/0xf2
[ 1083.866900] EIP: 0xb7eef549
[ 1083.866900] Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01
10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f
34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d 76 00 58 b8 77 00 00 00 cd 80 90
8d 76
[ 1083.866900] EAX: ffffffda EBX: 01200011 ECX: 00000000 EDX: 00000000
[ 1083.866900] ESI: 00000000 EDI: b7cf1ba8 EBP: b7cf1348 ESP: b7cf12f0
[ 1083.866900] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000246
[ 1083.866900] Modules linked in: algif_hash
[ 1083.866900] CR2: 00000000fe80c000
[ 1083.866900] ---[ end trace b07b25e6d94bccb1 ]---
[ 1083.866900] EIP: memcpy+0xf/0x20
[ 1083.866900] Code: 68 d0 7d ee d6 e8 11 1c c7 ff 0f 31 31 c3 59 58
eb 80 cc cc cc cc cc cc cc cc cc 55 89 e5 57 89 c7 56 89 d6 53 89 cb
c1 e9 02 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 5b 5e 5f 5d c3 90 55 89 e5
57 89
[ 1083.866900] EAX: fe80c000 EBX: 00010000 ECX: 00004000 EDX: fbfbd000
[ 1083.866900] ESI: fbfbd000 EDI: fe80c000 EBP: f11f1e2c ESP: f11f1e20
[ 1083.866900] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010216
[ 1083.866900] CR0: 80050033 CR2: fe80c000 CR3: 314c0000 CR4: 003506d0
[ 1083.866900] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 1083.866900] DR6: ffff4ff0 DR7: 00000400


Full test log link,
https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20200811/testrun/3052660/suite/linux-log-parser/test/check-kernel-bug-1659337/log

--
Linaro LKFT
https://lkft.linaro.org