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From:   Wei Chen <harperchen1110@gmail.com>
Date:   Mon, 31 Oct 2022 21:25:04 +0800
Message-ID: <CAO4mrfdU4oGktM8PPFg66=32N0JSGx=gtG80S89-b66tS3NLVw@mail.gmail.com>
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in gfs2_evict_inode
To:     rpeterso@redhat.com, agruenba@redhat.com, cluster-devel@redhat.com
Cc:     linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Dear Linux developers,

Here is the link to the reproducers.

C reproducer: https://drive.google.com/file/d/1P9GsW2pvEN_tvn89RYsrgnv2uDz3_6iq/view?usp=share_link
Syz reproducer:
https://drive.google.com/file/d/1Be-QEZ-hfj_CXhXlSEvzbf3E89HmkVMH/view?usp=share_link

The bug persists in the latest commit, v5.15.76 (4f5365f77018). I hope
it is helpful to you.

[   83.919419][ T6891]   function = gfs2_dirent_scan, file =
fs/gfs2/dir.c, line = 602
[   83.923713][ T6891] gfs2: fsid=syz:syz.0: about to withdraw this file system
[   83.929444][ T6891] gfs2: fsid=syz:syz.0: File system withdrawn
[   83.931468][ T6891] CPU: 1 PID: 6891 Comm: a.out Not tainted 5.15.76 #5
[   83.933492][ T6891] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014
[   83.936328][ T6891] Call Trace:
[   83.937107][ T6891]  <TASK>
[   83.937780][ T6891]  dump_stack_lvl+0x8d/0xcf
[   83.938843][ T6891]  gfs2_withdraw+0x212/0x730
[   83.939908][ T6891]  ? gfs2_dirent_scan+0x158/0x1a0
[   83.941070][ T6891]  gfs2_dirent_scan+0x158/0x1a0
[   83.942185][ T6891]  ? do_filldir_main.isra.21+0x1e0/0x1e0
[   83.943476][ T6891]  ? do_filldir_main.isra.21+0x1e0/0x1e0
[   83.944765][ T6891]  gfs2_dirent_search+0x156/0x2b0
[   83.945928][ T6891]  gfs2_dir_search+0x4a/0x120
[   83.947005][ T6891]  gfs2_lookupi+0x1ec/0x2c0
[   83.948042][ T6891]  ? gfs2_lookupi+0x12d/0x2c0
[   83.949127][ T6891]  ? gfs2_lookup_simple+0x57/0x90
[   83.950403][ T6891]  gfs2_lookup_simple+0x57/0x90
[   83.951522][ T6891]  init_inodes+0x6c/0xfd0
[   83.952527][ T6891]  ? snprintf+0x66/0x90
[   83.953544][ T6891]  ? gfs2_fill_super+0xa4d/0x1080
[   83.954695][ T6891]  gfs2_fill_super+0xa4d/0x1080
[   83.955809][ T6891]  ? gfs2_glock_nq_num+0x8f/0xe0
[   83.956946][ T6891]  ? snprintf+0x66/0x90
[   83.957905][ T6891]  ? set_blocksize+0x100/0x130
[   83.959011][ T6891]  ? gfs2_reconfigure+0x4c0/0x4c0
[   83.960164][ T6891]  ? get_tree_bdev+0x1c9/0x310
[   83.961270][ T6891]  get_tree_bdev+0x1c9/0x310
[   83.962579][ T6891]  gfs2_get_tree+0x24/0xc0
[   83.963992][ T6891]  vfs_get_tree+0x28/0x100
[   83.965423][ T6891]  path_mount+0x926/0xce0
[   83.966878][ T6891]  ? putname+0x83/0xa0
[   83.968251][ T6891]  do_mount+0x92/0xb0
[   83.969599][ T6891]  __x64_sys_mount+0xb0/0x120
[   83.971115][ T6891]  do_syscall_64+0x34/0xb0
[   83.972527][ T6891]  entry_SYSCALL_64_after_hwframe+0x61/0xcb
[   83.974433][ T6891] RIP: 0033:0x7f4669d7f48a
[   83.975836][ T6891] Code: 48 8b 0d 11 fa 2a 00 f7 d8 64 89 01 48 83
c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5
00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d de f9 2a 00 f7 d8
64 89 01 48
[   83.982060][ T6891] RSP: 002b:00007f466a46bd38 EFLAGS: 00000282
ORIG_RAX: 00000000000000a5
[   83.984695][ T6891] RAX: ffffffffffffffda RBX: 0000000000000000
RCX: 00007f4669d7f48a
[   83.986856][ T6891] RDX: 0000000020000000 RSI: 0000000020000100
RDI: 00007f466a46be70
[   83.988696][ T6891] RBP: 00007f466a46bef0 R08: 00007f466a46bd70
R09: 0000000000000000
[   83.990534][ T6891] R10: 0000000000000000 R11: 0000000000000282
R12: 00007ffd64dee9fe
[   83.992369][ T6891] R13: 00007ffd64dee9ff R14: 00007f466a44c000
R15: 0000000000000003
[   83.994218][ T6891]  </TASK>
[   83.997025][ T6891] gfs2: fsid=syz:syz.0: can't lookup journal index: 0
[   83.998884][ T6891] BUG: kernel NULL pointer dereference, address:
000000000000008c
[   84.000696][ T6891] #PF: supervisor read access in kernel mode
[   84.002075][ T6891] #PF: error_code(0x0000) - not-present page
[   84.003452][ T6891] PGD 109056067 P4D 109056067 PUD 109057067 PMD 0
[   84.004955][ T6891] Oops: 0000 [#1] PREEMPT SMP
[   84.006026][ T6891] CPU: 1 PID: 6891 Comm: a.out Not tainted 5.15.76 #5
[   84.007585][ T6891] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014
[   84.010444][ T6891] RIP: 0010:gfs2_evict_inode+0x39f/0x910
[   84.011742][ T6891] Code: 02 37 ff be 01 00 00 00 48 89 df e8 ab 38
60 ff 48 8b bb b8 04 00 00 31 f6 e8 7d 95 fd ff 49 8b 87 00 09 00 00
31 f6 4c 89 ff <8b> 90 8c 00 00 00 e8 56 43 00 00 85 c0 89 85 60 ff ff
ff 75 25 e8
[   84.016251][ T6891] RSP: 0018:ffffc900025d3b00 EFLAGS: 00010246
[   84.017655][ T6891] RAX: 0000000000000000 RBX: ffff88810cb10650
RCX: 0000000000000000
[   84.019490][ T6891] RDX: ffff88810ab15340 RSI: 0000000000000000
RDI: ffff88810c1bc000
[   84.021329][ T6891] RBP: ffffc900025d3bb0 R08: 0000000000000001
R09: 0000000000000000
[   84.023160][ T6891] R10: ffffc900025d38f8 R11: 0000000000000001
R12: ffff88810cb10b88
[   84.024992][ T6891] R13: ffff88810cb10878 R14: ffff88810c1bc000
R15: ffff88810c1bc000
[   84.026825][ T6891] FS:  00007f466a46c700(0000)
GS:ffff88813dc00000(0000) knlGS:0000000000000000
[   84.028869][ T6891] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   84.030382][ T6891] CR2: 000000000000008c CR3: 000000010c054000
CR4: 00000000003506e0
[   84.032206][ T6891] DR0: 0000000000000000 DR1: 0000000000000000
DR2: 0000000000000000
[   84.034034][ T6891] DR3: 0000000000000000 DR6: 00000000fffe0ff0
DR7: 0000000000000400
[   84.035859][ T6891] Call Trace:
[   84.036615][ T6891]  <TASK>
[   84.037294][ T6891]  ? find_held_lock+0x2d/0x90
[   84.038375][ T6891]  ? gfs2_evict_inode+0x2c7/0x910
[   84.039537][ T6891]  ? evict_unlinked_inode+0x380/0x380
[   84.040773][ T6891]  ? evict+0xfd/0x1e0
[   84.041694][ T6891]  evict+0xfd/0x1e0
[   84.042571][ T6891]  ? gfs2_glock_put_eventually+0x40/0x40
[   84.043866][ T6891]  iput.part.20+0x217/0x3a0
[   84.044949][ T6891]  iput+0x29/0x40
[   84.045790][ T6891]  dentry_unlink_inode+0x163/0x170
[   84.046971][ T6891]  __dentry_kill+0x137/0x220
[   84.048032][ T6891]  ? dput+0x32/0x650
[   84.048936][ T6891]  dput+0x42b/0x650
[   84.049814][ T6891]  gfs2_fill_super+0xa94/0x1080
[   84.050932][ T6891]  ? gfs2_glock_nq_num+0x8f/0xe0
[   84.052068][ T6891]  ? snprintf+0x66/0x90
[   84.053036][ T6891]  ? set_blocksize+0x100/0x130
[   84.054137][ T6891]  ? gfs2_reconfigure+0x4c0/0x4c0
[   84.055292][ T6891]  ? get_tree_bdev+0x1c9/0x310
[   84.056391][ T6891]  get_tree_bdev+0x1c9/0x310
[   84.057457][ T6891]  gfs2_get_tree+0x24/0xc0
[   84.058474][ T6891]  vfs_get_tree+0x28/0x100
[   84.059489][ T6891]  path_mount+0x926/0xce0
[   84.060486][ T6891]  ? putname+0x83/0xa0
[   84.061432][ T6891]  do_mount+0x92/0xb0
[   84.062353][ T6891]  __x64_sys_mount+0xb0/0x120
[   84.063437][ T6891]  do_syscall_64+0x34/0xb0
[   84.064455][ T6891]  entry_SYSCALL_64_after_hwframe+0x61/0xcb
[   84.065811][ T6891] RIP: 0033:0x7f4669d7f48a
[   84.066822][ T6891] Code: 48 8b 0d 11 fa 2a 00 f7 d8 64 89 01 48 83
c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5
00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d de f9 2a 00 f7 d8
64 89 01 48
[   84.071310][ T6891] RSP: 002b:00007f466a46bd38 EFLAGS: 00000282
ORIG_RAX: 00000000000000a5
[   84.073242][ T6891] RAX: ffffffffffffffda RBX: 0000000000000000
RCX: 00007f4669d7f48a
[   84.075069][ T6891] RDX: 0000000020000000 RSI: 0000000020000100
RDI: 00007f466a46be70
[   84.076892][ T6891] RBP: 00007f466a46bef0 R08: 00007f466a46bd70
R09: 0000000000000000
[   84.078724][ T6891] R10: 0000000000000000 R11: 0000000000000282
R12: 00007ffd64dee9fe
[   84.080598][ T6891] R13: 00007ffd64dee9ff R14: 00007f466a44c000
R15: 0000000000000003
[   84.082437][ T6891]  </TASK>
[   84.083141][ T6891] Modules linked in:
[   84.084084][ T6891] CR2: 000000000000008c
[   84.085089][ T6891] ---[ end trace 7249ef596cc64205 ]---
[   84.086343][ T6891] RIP: 0010:gfs2_evict_inode+0x39f/0x910
[   84.087642][ T6891] Code: 02 37 ff be 01 00 00 00 48 89 df e8 ab 38
60 ff 48 8b bb b8 04 00 00 31 f6 e8 7d 95 fd ff 49 8b 87 00 09 00 00
31 f6 4c 89 ff <8b> 90 8c 00 00 00 e8 56 43 00 00 85 c0 89 85 60 ff ff
ff 75 25 e8
[   84.092183][ T6891] RSP: 0018:ffffc900025d3b00 EFLAGS: 00010246
[   84.093581][ T6891] RAX: 0000000000000000 RBX: ffff88810cb10650
RCX: 0000000000000000
[   84.095407][ T6891] RDX: ffff88810ab15340 RSI: 0000000000000000
RDI: ffff88810c1bc000
[   84.097245][ T6891] RBP: ffffc900025d3bb0 R08: 0000000000000001
R09: 0000000000000000
[   84.099079][ T6891] R10: ffffc900025d38f8 R11: 0000000000000001
R12: ffff88810cb10b88
[   84.100917][ T6891] R13: ffff88810cb10878 R14: ffff88810c1bc000
R15: ffff88810c1bc000
[   84.102756][ T6891] FS:  00007f466a46c700(0000)
GS:ffff88813dc00000(0000) knlGS:0000000000000000
[   84.104808][ T6891] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   84.106320][ T6891] CR2: 000000000000008c CR3: 000000010c054000
CR4: 00000000003506e0
[   84.108160][ T6891] DR0: 0000000000000000 DR1: 0000000000000000
DR2: 0000000000000000
[   84.109992][ T6891] DR3: 0000000000000000 DR6: 00000000fffe0ff0
DR7: 0000000000000400
[   84.111822][ T6891] Kernel panic - not syncing: Fatal exception
[   84.113908][ T6891] Kernel Offset: disabled
[   84.114912][ T6891] Rebooting in 86400 seconds..

Best,
Wei