2022-10-30 09:19:32

by Wei Chen

[permalink] [raw]
Subject: BUG: unable to handle kernel NULL pointer dereference in gfs2_evict_inode

Dear Linux Developer,

Recently when using our tool to fuzz kernel, the following crash was triggered:

HEAD commit: 64570fbc14f8 Linux 5.15-rc5
git tree: upstream
compiler: gcc 8.0.1
console output:
https://drive.google.com/file/d/1yppAEEN16x0lR3fd5t-NQ1itCoKLFtfP/view?usp=share_link
kernel config: https://drive.google.com/file/d/1uDOeEYgJDcLiSOrx9W8v2bqZ6uOA_55t/view?usp=share_link

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: Wei Chen <[email protected]>

RBP: 0000000020000000 R08: 00007f39b7fa3af0 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000100
R13: 00007f39b7fa3ab0 R14: 0000000000000001 R15: 0000000020047a20
gfs2: fsid=syz:syz.0: can't lookup journal index: 0
BUG: kernel NULL pointer dereference, address: 000000000000008c
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD c1e1067 P4D c1e1067 PUD 1a9e8067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 11045 Comm: syz-executor.0 Not tainted 5.15.0-rc5 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014
RIP: 0010:gfs2_evict_inode+0x47b/0xb00
Code: 3b 14 ff be 01 00 00 00 48 89 df e8 af 6f 44 ff 48 8b bb b8 04
00 00 31 f6 e8 e1 47 fd ff 49 8b 87 00 09 00 00 31 f6 4c 89 ff <8b> 90
8c 00 00 00 e8 ba 4a 00 00 31 ff 41 89 c5 89 c6 e8 ae 3c 14
RSP: 0018:ffffc9000df7fb10 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888016648d10 RCX: 0000000000040000
RDX: ffffc900013d5000 RSI: 0000000000000000 RDI: ffff88801a800000
RBP: ffffc9000df7fbc0 R08: ffffffff8229378f R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff888016648f38
R13: 0000000000000000 R14: ffff88801a800000 R15: ffff88801a800000
FS: 00007f39b7fa4700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000008c CR3: 0000000017567000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
evict+0x11c/0x230
iput+0x2e9/0x500
dentry_unlink_inode+0x111/0x1a0
__dentry_kill+0x186/0x280
dput.part.32+0x60d/0x940
gfs2_fill_super+0x8c1/0x10f0
get_tree_bdev+0x243/0x340
gfs2_get_tree+0x24/0xd0
vfs_get_tree+0x29/0x100
path_mount+0x58e/0x10a0
do_mount+0x9b/0xb0
__x64_sys_mount+0x13a/0x150
do_syscall_64+0x34/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x46abda
Code: 48 c7 c1 bc ff ff ff 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 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f39b7fa3a48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f39b7fa3af0 RCX: 000000000046abda
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f39b7fa3ab0
RBP: 0000000020000000 R08: 00007f39b7fa3af0 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000100
R13: 00007f39b7fa3ab0 R14: 0000000000000001 R15: 0000000020047a20
Modules linked in:
CR2: 000000000000008c
---[ end trace 194497c38992c5b1 ]---
RIP: 0010:gfs2_evict_inode+0x47b/0xb00
Code: 3b 14 ff be 01 00 00 00 48 89 df e8 af 6f 44 ff 48 8b bb b8 04
00 00 31 f6 e8 e1 47 fd ff 49 8b 87 00 09 00 00 31 f6 4c 89 ff <8b> 90
8c 00 00 00 e8 ba 4a 00 00 31 ff 41 89 c5 89 c6 e8 ae 3c 14
RSP: 0018:ffffc9000df7fb10 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888016648d10 RCX: 0000000000040000
RDX: ffffc900013d5000 RSI: 0000000000000000 RDI: ffff88801a800000
RBP: ffffc9000df7fbc0 R08: ffffffff8229378f R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff888016648f38
R13: 0000000000000000 R14: ffff88801a800000 R15: ffff88801a800000
FS: 00007f39b7fa4700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000008c CR3: 0000000017567000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 3b 14 ff cmp (%rdi,%rdi,8),%edx
3: be 01 00 00 00 mov $0x1,%esi
8: 48 89 df mov %rbx,%rdi
b: e8 af 6f 44 ff callq 0xff446fbf
10: 48 8b bb b8 04 00 00 mov 0x4b8(%rbx),%rdi
17: 31 f6 xor %esi,%esi
19: e8 e1 47 fd ff callq 0xfffd47ff
1e: 49 8b 87 00 09 00 00 mov 0x900(%r15),%rax
25: 31 f6 xor %esi,%esi
27: 4c 89 ff mov %r15,%rdi
* 2a: 8b 90 8c 00 00 00 mov 0x8c(%rax),%edx <-- trapping instruction
30: e8 ba 4a 00 00 callq 0x4aef
35: 31 ff xor %edi,%edi
37: 41 89 c5 mov %eax,%r13d
3a: 89 c6 mov %eax,%esi
3c: e8 .byte 0xe8
3d: ae scas %es:(%rdi),%al
3e: 3c 14 cmp $0x14,%al

Best,
Wei


2022-10-31 13:43:23

by Wei Chen

[permalink] [raw]
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in gfs2_evict_inode

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

2022-11-18 08:17:26

by Wei Chen

[permalink] [raw]
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in gfs2_evict_inode

Dear Linux developers,

The bug persists in upstream Linux v6.0-rc5.

R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20
</TASK>
gfs2: fsid=syz:syz.0: can't read journal index: -5
BUG: kernel NULL pointer dereference, address: 0000000000000064
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 28908067 P4D 28908067 PUD 28909067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 14812 Comm: syz-executor.1 Not tainted
6.1.0-rc5-63183-gd418a331631b #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
Ubuntu-1.8.2-1ubuntu1 04/01/2014
RIP: 0010:evict_linked_inode fs/gfs2/super.c:1330 [inline]
RIP: 0010:gfs2_evict_inode+0x449/0xb70 fs/gfs2/super.c:1385
Code: 00 00 00 48 89 df e8 46 13 5a ff 48 8b bb a8 02 00 00 31 f6 e8
d8 70 fd ff 48 8b 4c 24 20 31 f6 48 8b 81 b0 05 00 00 48 89 cf <8b> 50
64 e8 5f 4b 00 00 31 ff 41 89 c7 89 c6 e8 e3 86 2d ff 45 85
RSP: 0018:ffff88802aec3a80 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88800eb70f00 RCX: ffff888028c58000
RDX: ffffc900092dc000 RSI: 0000000000000000 RDI: ffff888028c58000
RBP: ffff88802aec3b38 R08: ffffffff81fb50c2 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88800eb71228
R13: ffff88800eb71078 R14: ffff888028c58000 R15: 0000000000000000
FS: 00007fd4381ff700(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000064 CR3: 0000000028c0f000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000002 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
evict+0x122/0x230 fs/inode.c:664
iput_final fs/inode.c:1747 [inline]
iput fs/inode.c:1773 [inline]
iput+0x317/0x390 fs/inode.c:1759
init_journal fs/gfs2/ops_fstype.c:875 [inline]
init_inodes+0x433/0xd80 fs/gfs2/ops_fstype.c:889
gfs2_fill_super+0x9a2/0xf20 fs/gfs2/ops_fstype.c:1247
get_tree_bdev+0x224/0x320 fs/super.c:1324
gfs2_get_tree+0x27/0xd0 fs/gfs2/ops_fstype.c:1330
vfs_get_tree+0x2c/0x100 fs/super.c:1531
do_new_mount fs/namespace.c:3040 [inline]
path_mount+0x75c/0x1020 fs/namespace.c:3370
do_mount+0xa2/0xc0 fs/namespace.c:3383
__do_sys_mount fs/namespace.c:3591 [inline]
__se_sys_mount fs/namespace.c:3568 [inline]
__x64_sys_mount+0x13e/0x150 fs/namespace.c:3568
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x34/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x46174a
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 bd 86 fb ff c3 66
2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d
01 f0 ff ff 0f 83 9a 86 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007fd4381fea78 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd4381feb10 RCX: 000000000046174a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fd4381fead0
RBP: 00007fd4381fead0 R08: 00007fd4381feb10 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20
</TASK>
Modules linked in:
CR2: 0000000000000064
---[ end trace 0000000000000000 ]---
RIP: 0010:evict_linked_inode fs/gfs2/super.c:1330 [inline]
RIP: 0010:gfs2_evict_inode+0x449/0xb70 fs/gfs2/super.c:1385
Code: 00 00 00 48 89 df e8 46 13 5a ff 48 8b bb a8 02 00 00 31 f6 e8
d8 70 fd ff 48 8b 4c 24 20 31 f6 48 8b 81 b0 05 00 00 48 89 cf <8b> 50
64 e8 5f 4b 00 00 31 ff 41 89 c7 89 c6 e8 e3 86 2d ff 45 85
RSP: 0018:ffff88802aec3a80 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88800eb70f00 RCX: ffff888028c58000
RDX: ffffc900092dc000 RSI: 0000000000000000 RDI: ffff888028c58000
RBP: ffff88802aec3b38 R08: ffffffff81fb50c2 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88800eb71228
R13: ffff88800eb71078 R14: ffff888028c58000 R15: 0000000000000000
FS: 00007fd4381ff700(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000064 CR3: 0000000028c0f000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000002 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 48 89 add %cl,-0x77(%rax)
5: df e8 fucomip %st(0),%st
7: 46 13 5a ff rex.RX adc -0x1(%rdx),%r11d
b: 48 8b bb a8 02 00 00 mov 0x2a8(%rbx),%rdi
12: 31 f6 xor %esi,%esi
14: e8 d8 70 fd ff callq 0xfffd70f1
19: 48 8b 4c 24 20 mov 0x20(%rsp),%rcx
1e: 31 f6 xor %esi,%esi
20: 48 8b 81 b0 05 00 00 mov 0x5b0(%rcx),%rax
27: 48 89 cf mov %rcx,%rdi
* 2a: 8b 50 64 mov 0x64(%rax),%edx <-- trapping instruction
2d: e8 5f 4b 00 00 callq 0x4b91
32: 31 ff xor %edi,%edi
34: 41 89 c7 mov %eax,%r15d
37: 89 c6 mov %eax,%esi
39: e8 e3 86 2d ff callq 0xff2d8721
3e: 45 rex.RB
3f: 85 .byte 0x85

Best,
Wei

On Mon, 31 Oct 2022 at 21:25, Wei Chen <[email protected]> wrote:
>
> 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

2022-11-18 10:00:47

by Dmitry Vyukov

[permalink] [raw]
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in gfs2_evict_inode

On Fri, 18 Nov 2022 at 09:06, Wei Chen <[email protected]> wrote:
>
> Dear Linux developers,
>
> The bug persists in upstream Linux v6.0-rc5.

If you fix this, please also add the syzbot tag:

Reported-by: [email protected]
https://lore.kernel.org/all/[email protected]/

> R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
> R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20
> </TASK>
> gfs2: fsid=syz:syz.0: can't read journal index: -5
> BUG: kernel NULL pointer dereference, address: 0000000000000064
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 28908067 P4D 28908067 PUD 28909067 PMD 0
> Oops: 0000 [#1] PREEMPT SMP
> CPU: 0 PID: 14812 Comm: syz-executor.1 Not tainted
> 6.1.0-rc5-63183-gd418a331631b #1
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> Ubuntu-1.8.2-1ubuntu1 04/01/2014
> RIP: 0010:evict_linked_inode fs/gfs2/super.c:1330 [inline]
> RIP: 0010:gfs2_evict_inode+0x449/0xb70 fs/gfs2/super.c:1385
> Code: 00 00 00 48 89 df e8 46 13 5a ff 48 8b bb a8 02 00 00 31 f6 e8
> d8 70 fd ff 48 8b 4c 24 20 31 f6 48 8b 81 b0 05 00 00 48 89 cf <8b> 50
> 64 e8 5f 4b 00 00 31 ff 41 89 c7 89 c6 e8 e3 86 2d ff 45 85
> RSP: 0018:ffff88802aec3a80 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: ffff88800eb70f00 RCX: ffff888028c58000
> RDX: ffffc900092dc000 RSI: 0000000000000000 RDI: ffff888028c58000
> RBP: ffff88802aec3b38 R08: ffffffff81fb50c2 R09: 0000000000000000
> R10: 0000000000000005 R11: 0000000000000000 R12: ffff88800eb71228
> R13: ffff88800eb71078 R14: ffff888028c58000 R15: 0000000000000000
> FS: 00007fd4381ff700(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000064 CR3: 0000000028c0f000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000002 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> evict+0x122/0x230 fs/inode.c:664
> iput_final fs/inode.c:1747 [inline]
> iput fs/inode.c:1773 [inline]
> iput+0x317/0x390 fs/inode.c:1759
> init_journal fs/gfs2/ops_fstype.c:875 [inline]
> init_inodes+0x433/0xd80 fs/gfs2/ops_fstype.c:889
> gfs2_fill_super+0x9a2/0xf20 fs/gfs2/ops_fstype.c:1247
> get_tree_bdev+0x224/0x320 fs/super.c:1324
> gfs2_get_tree+0x27/0xd0 fs/gfs2/ops_fstype.c:1330
> vfs_get_tree+0x2c/0x100 fs/super.c:1531
> do_new_mount fs/namespace.c:3040 [inline]
> path_mount+0x75c/0x1020 fs/namespace.c:3370
> do_mount+0xa2/0xc0 fs/namespace.c:3383
> __do_sys_mount fs/namespace.c:3591 [inline]
> __se_sys_mount fs/namespace.c:3568 [inline]
> __x64_sys_mount+0x13e/0x150 fs/namespace.c:3568
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x34/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x46174a
> Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 bd 86 fb ff c3 66
> 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d
> 01 f0 ff ff 0f 83 9a 86 fb ff c3 66 0f 1f 84 00 00 00 00 00
> RSP: 002b:00007fd4381fea78 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
> RAX: ffffffffffffffda RBX: 00007fd4381feb10 RCX: 000000000046174a
> RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fd4381fead0
> RBP: 00007fd4381fead0 R08: 00007fd4381feb10 R09: 0000000020000000
> R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
> R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020047a20
> </TASK>
> Modules linked in:
> CR2: 0000000000000064
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:evict_linked_inode fs/gfs2/super.c:1330 [inline]
> RIP: 0010:gfs2_evict_inode+0x449/0xb70 fs/gfs2/super.c:1385
> Code: 00 00 00 48 89 df e8 46 13 5a ff 48 8b bb a8 02 00 00 31 f6 e8
> d8 70 fd ff 48 8b 4c 24 20 31 f6 48 8b 81 b0 05 00 00 48 89 cf <8b> 50
> 64 e8 5f 4b 00 00 31 ff 41 89 c7 89 c6 e8 e3 86 2d ff 45 85
> RSP: 0018:ffff88802aec3a80 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: ffff88800eb70f00 RCX: ffff888028c58000
> RDX: ffffc900092dc000 RSI: 0000000000000000 RDI: ffff888028c58000
> RBP: ffff88802aec3b38 R08: ffffffff81fb50c2 R09: 0000000000000000
> R10: 0000000000000005 R11: 0000000000000000 R12: ffff88800eb71228
> R13: ffff88800eb71078 R14: ffff888028c58000 R15: 0000000000000000
> FS: 00007fd4381ff700(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000064 CR3: 0000000028c0f000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000002 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
> 0: 00 00 add %al,(%rax)
> 2: 00 48 89 add %cl,-0x77(%rax)
> 5: df e8 fucomip %st(0),%st
> 7: 46 13 5a ff rex.RX adc -0x1(%rdx),%r11d
> b: 48 8b bb a8 02 00 00 mov 0x2a8(%rbx),%rdi
> 12: 31 f6 xor %esi,%esi
> 14: e8 d8 70 fd ff callq 0xfffd70f1
> 19: 48 8b 4c 24 20 mov 0x20(%rsp),%rcx
> 1e: 31 f6 xor %esi,%esi
> 20: 48 8b 81 b0 05 00 00 mov 0x5b0(%rcx),%rax
> 27: 48 89 cf mov %rcx,%rdi
> * 2a: 8b 50 64 mov 0x64(%rax),%edx <-- trapping instruction
> 2d: e8 5f 4b 00 00 callq 0x4b91
> 32: 31 ff xor %edi,%edi
> 34: 41 89 c7 mov %eax,%r15d
> 37: 89 c6 mov %eax,%esi
> 39: e8 e3 86 2d ff callq 0xff2d8721
> 3e: 45 rex.RB
> 3f: 85 .byte 0x85
>
> Best,
> Wei
>
> On Mon, 31 Oct 2022 at 21:25, Wei Chen <[email protected]> wrote:
> >
> > 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
>
> --
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2022-11-22 06:26:29

by Matthew Wilcox

[permalink] [raw]
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in gfs2_evict_inode

On Fri, Nov 18, 2022 at 10:33:21AM +0100, Dmitry Vyukov wrote:
> On Fri, 18 Nov 2022 at 09:06, Wei Chen <[email protected]> wrote:
> >
> > Dear Linux developers,
> >
> > The bug persists in upstream Linux v6.0-rc5.
>
> If you fix this, please also add the syzbot tag:
>
> Reported-by: [email protected]
> https://lore.kernel.org/all/[email protected]/

Hey Dmitri, does Wei Chen work with you? They're not responding to
requests to understand what they're doing. eg:

https://lore.kernel.org/all/[email protected]/

https://lore.kernel.org/all/[email protected]/

I'm just ignoring their reports now.

2022-11-22 07:35:40

by Dmitry Vyukov

[permalink] [raw]
Subject: Re: BUG: unable to handle kernel NULL pointer dereference in gfs2_evict_inode

On Tue, 22 Nov 2022 at 07:03, Matthew Wilcox <[email protected]> wrote:
> > > Dear Linux developers,
> > >
> > > The bug persists in upstream Linux v6.0-rc5.
> >
> > If you fix this, please also add the syzbot tag:
> >
> > Reported-by: [email protected]
> > https://lore.kernel.org/all/[email protected]/
>
> Hey Dmitri, does Wei Chen work with you? They're not responding to
> requests to understand what they're doing. eg:
>
> https://lore.kernel.org/all/[email protected]/
>
> https://lore.kernel.org/all/[email protected]/
>
> I'm just ignoring their reports now.

No, I know nothing about this.