Re: [f2fs] ab2dbddfd0: BUG:kernel_NULL_pointer_dereference,address
From: Chao Yu
Date: Tue Mar 16 2021 - 04:34:55 EST
Hi Sahitya,
Node manager was initialized after segment manager's initialization,
so f2fs_available_free_memory() called from issue_discard_thread()
may access invalid nm_i pointer, could you please check and fix
this case?
On 2021/3/16 12:58, kernel test robot wrote:
Greeting,
FYI, we noticed the following commit (built with gcc-9):
commit: ab2dbddfd064f2078a7099e4d65cce54f5ef5e71 ("[PATCH v2] f2fs: allow to change discard policy based on cached discard cmds")
url: https://github.com/0day-ci/linux/commits/Sahitya-Tummala/f2fs-allow-to-change-discard-policy-based-on-cached-discard-cmds/20210311-170257
in testcase: ltp
version: ltp-x86_64-14c1f76-1_20210315
with following parameters:
disk: 1HDD
fs: f2fs
test: io
ucode: 0x21
test-description: The LTP testsuite contains a collection of tools for testing the Linux kernel and related features.
test-url: http://linux-test-project.github.io/
on test machine: 4 threads Intel(R) Core(TM) i3-3220 CPU @ 3.30GHz with 8G memory
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 <oliver.sang@xxxxxxxxx>
[ 38.378402] BUG: kernel NULL pointer dereference, address: 0000000000000010
[ 38.378526] #PF: supervisor read access in kernel mode
[ 38.378610] #PF: error_code(0x0000) - not-present page
[ 38.378694] PGD 0 P4D 0
[ 38.378739] Oops: 0000 [#1] SMP PTI
[ 38.378799] CPU: 2 PID: 2436 Comm: f2fs_discard-8: Not tainted 5.12.0-rc2-00001-gab2dbddfd064 #1
[ 38.378940] Hardware name: Hewlett-Packard p6-1451cx/2ADA, BIOS 8.15 02/05/2013
[ 38.379057] RIP: 0010:f2fs_available_free_memory (kbuild/src/consumer/fs/f2fs/node.c:96) f2fs
[ 38.379237] Code: 04 00 00 48 0f af d6 48 be c3 f5 28 5c 8f c2 f5 28 48 c1 ea 02 48 89 d0 48 f7 e6 48 c1 ea 03 48 39 ca 0f 97 c0 e9 af fe ff ff <41> 8b 54 24 10 49 63 8d 94 20 00 00 48 0f af d6 48 be c3 f5 28 5c
All code
========
0: 04 00 add $0x0,%al
2: 00 48 0f add %cl,0xf(%rax)
5: af scas %es:(%rdi),%eax
6: d6 (bad)
7: 48 be c3 f5 28 5c 8f movabs $0x28f5c28f5c28f5c3,%rsi
e: c2 f5 28
11: 48 c1 ea 02 shr $0x2,%rdx
15: 48 89 d0 mov %rdx,%rax
18: 48 f7 e6 mul %rsi
1b: 48 c1 ea 03 shr $0x3,%rdx
1f: 48 39 ca cmp %rcx,%rdx
22: 0f 97 c0 seta %al
25: e9 af fe ff ff jmpq 0xfffffffffffffed9
2a:* 41 8b 54 24 10 mov 0x10(%r12),%edx <-- trapping instruction
2f: 49 63 8d 94 20 00 00 movslq 0x2094(%r13),%rcx
36: 48 0f af d6 imul %rsi,%rdx
3a: 48 rex.W
3b: be c3 f5 28 5c mov $0x5c28f5c3,%esi
Code starting with the faulting instruction
===========================================
0: 41 8b 54 24 10 mov 0x10(%r12),%edx
5: 49 63 8d 94 20 00 00 movslq 0x2094(%r13),%rcx
c: 48 0f af d6 imul %rsi,%rdx
10: 48 rex.W
11: be c3 f5 28 5c mov $0x5c28f5c3,%esi
[ 38.379531] RSP: 0018:ffffc900006f3dd8 EFLAGS: 00010246
[ 38.379617] RAX: 0000000000000106 RBX: ffff888213317000 RCX: 00000000001e9c8c
[ 38.379731] RDX: ffff88810c84b430 RSI: 00000000001e9c8c RDI: ffff88810c84b540
[ 38.379844] RBP: 0000000000000006 R08: 0000000000000106 R09: ffff88821fb2bc58
[ 38.379958] R10: 000000000000032e R11: ffff88821fb2a144 R12: 0000000000000000
[ 38.380071] R13: ffff88820b7e4000 R14: 000000000000ea60 R15: 0000000000000000
[ 38.380185] FS: 0000000000000000(0000) GS:ffff88821fb00000(0000) knlGS:0000000000000000
[ 38.380315] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 38.380408] CR2: 0000000000000010 CR3: 000000021e00a003 CR4: 00000000001706e0
[ 38.380522] Call Trace:
[ 38.380619] ? del_timer_sync (kbuild/src/consumer/kernel/time/timer.c:1394)
[ 38.380686] ? prepare_to_wait_event (kbuild/src/consumer/kernel/sched/wait.c:323 (discriminator 15))
[ 38.380762] ? __next_timer_interrupt (kbuild/src/consumer/kernel/time/timer.c:1816)
[ 38.380841] issue_discard_thread (kbuild/src/consumer/fs/f2fs/segment.c:1759 (discriminator 1)) f2fs
[ 38.380937] ? finish_wait (kbuild/src/consumer/kernel/sched/wait.c:403)
[ 38.380997] ? __issue_discard_cmd (kbuild/src/consumer/fs/f2fs/segment.c:1722) f2fs
[ 38.381094] kthread (kbuild/src/consumer/kernel/kthread.c:292)
[ 38.381151] ? kthread_park (kbuild/src/consumer/kernel/kthread.c:245)
[ 38.381213] ret_from_fork (kbuild/src/consumer/arch/x86/entry/entry_64.S:300)
[ 38.381276] Modules linked in: dm_mod f2fs netconsole btrfs blake2b_generic xor zstd_compress raid6_pq libcrc32c sd_mod t10_pi sg intel_rapl_msr intel_rapl_common i915 x86_pkg_temp_thermal intel_powerclamp coretemp intel_gtt crct10dif_pclmul crc32_pclmul drm_kms_helper crc32c_intel usb_storage ghash_clmulni_intel syscopyarea rapl ahci libahci sysfillrect sysimgblt fb_sys_fops ipmi_devintf ipmi_msghandler intel_cstate drm libata intel_uncore mei_me mei video ip_tables
[ 38.381939] CR2: 0000000000000010
[ 38.381996] ---[ end trace d47b1e3f3cb425e8 ]---
[ 38.382072] RIP: 0010:f2fs_available_free_memory (kbuild/src/consumer/fs/f2fs/node.c:96) f2fs
[ 38.382188] Code: 04 00 00 48 0f af d6 48 be c3 f5 28 5c 8f c2 f5 28 48 c1 ea 02 48 89 d0 48 f7 e6 48 c1 ea 03 48 39 ca 0f 97 c0 e9 af fe ff ff <41> 8b 54 24 10 49 63 8d 94 20 00 00 48 0f af d6 48 be c3 f5 28 5c
All code
========
0: 04 00 add $0x0,%al
2: 00 48 0f add %cl,0xf(%rax)
5: af scas %es:(%rdi),%eax
6: d6 (bad)
7: 48 be c3 f5 28 5c 8f movabs $0x28f5c28f5c28f5c3,%rsi
e: c2 f5 28
11: 48 c1 ea 02 shr $0x2,%rdx
15: 48 89 d0 mov %rdx,%rax
18: 48 f7 e6 mul %rsi
1b: 48 c1 ea 03 shr $0x3,%rdx
1f: 48 39 ca cmp %rcx,%rdx
22: 0f 97 c0 seta %al
25: e9 af fe ff ff jmpq 0xfffffffffffffed9
2a:* 41 8b 54 24 10 mov 0x10(%r12),%edx <-- trapping instruction
2f: 49 63 8d 94 20 00 00 movslq 0x2094(%r13),%rcx
36: 48 0f af d6 imul %rsi,%rdx
3a: 48 rex.W
3b: be c3 f5 28 5c mov $0x5c28f5c3,%esi
Code starting with the faulting instruction
===========================================
0: 41 8b 54 24 10 mov 0x10(%r12),%edx
5: 49 63 8d 94 20 00 00 movslq 0x2094(%r13),%rcx
c: 48 0f af d6 imul %rsi,%rdx
10: 48 rex.W
11: be c3 f5 28 5c mov $0x5c28f5c3,%esi
To reproduce:
git clone https://github.com/intel/lkp-tests.git
cd lkp-tests
bin/lkp install job.yaml # job file is attached in this email
bin/lkp split-job --compatible job.yaml
bin/lkp run compatible-job.yaml
---
0DAY/LKP+ Test Infrastructure Open Source Technology Center
https://lists.01.org/hyperkitty/list/lkp@xxxxxxxxxxxx Intel Corporation
Thanks,
Oliver Sang