[syzbot] BUG: unable to handle kernel NULL pointer dereference in reiserfs_set_acl

From: syzbot
Date: Tue Oct 04 2022 - 11:07:03 EST


syzbot found the following issue on:

HEAD commit: bbed346d5a96 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=17ec92cc880000
kernel config: https://syzkaller.appspot.com/x/.config?x=aae2d21e7dd80684
dashboard link: https://syzkaller.appspot.com/bug?extid=27d15e986992eff93cd9
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/11078f50b80b/disk-bbed346d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/398e5f1e6c84/vmlinux-bbed346d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+27d15e986992eff93cd9@xxxxxxxxxxxxxxxxxxxxxxxxx

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000068
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x06: level 2 translation fault
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=0000000131b9c000
[0000000000000068] pgd=080000013f9b8003, p4d=080000013f9b8003, pud=080000012eae9003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 2588 Comm: syz-executor.3 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : d_really_is_negative include/linux/dcache.h:465 [inline]
pc : reiserfs_xattr_jcreate_nblocks fs/reiserfs/xattr.h:79 [inline]
pc : reiserfs_set_acl+0xd0/0x2c0 fs/reiserfs/xattr_acl.c:36
lr : reiserfs_xattr_jcreate_nblocks fs/reiserfs/xattr.h:78 [inline]
lr : reiserfs_set_acl+0xc0/0x2c0 fs/reiserfs/xattr_acl.c:36
sp : ffff80001688b990
x29: ffff80001688b9e0 x28: ffff0000c8cdfc00 x27: 0000000000000002
x26: 0000000000000000 x25: 0000000000000036 x24: 000000000000002b
x23: 0000000000000000 x22: ffff0000eb2ee000 x21: ffff0000ef1d5380
x20: 0000000000004000 x19: ffff0000ed8f8de0 x18: 00000000000000c0
x17: ffff80000dd0b198 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000002 x13: 0000000000000020 x12: 0000000000040000
x11: 00000000000042eb x10: 000000000000006c x9 : 00000000000001c0
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 000000000000003f
x5 : 0000000000000c40 x4 : 0000000000000080 x3 : 0000000000004000
x2 : ffff0000ef1d5380 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
reiserfs_xattr_jcreate_nblocks fs/reiserfs/xattr.h:78 [inline]
reiserfs_set_acl+0xd0/0x2c0 fs/reiserfs/xattr_acl.c:36
set_posix_acl fs/posix_acl.c:1015 [inline]
posix_acl_xattr_set+0x1dc/0x23c fs/posix_acl.c:1034
__vfs_setxattr+0x250/0x260 fs/xattr.c:182
__vfs_setxattr_noperm+0xcc/0x320 fs/xattr.c:216
__vfs_setxattr_locked+0x16c/0x194 fs/xattr.c:277
vfs_setxattr+0x174/0x280 fs/xattr.c:313
do_setxattr fs/xattr.c:600 [inline]
setxattr fs/xattr.c:623 [inline]
path_setxattr+0x354/0x414 fs/xattr.c:642
__do_sys_lsetxattr fs/xattr.c:665 [inline]
__se_sys_lsetxattr fs/xattr.c:661 [inline]
__arm64_sys_lsetxattr+0x2c/0x40 fs/xattr.c:661
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
Code: f942d388 f10002ff 52803809 52800d8a (f9403508)
---[ end trace 0000000000000000 ]---
Code disassembly (best guess):
0: f942d388 ldr x8, [x28, #1440]
4: f10002ff cmp x23, #0x0
8: 52803809 mov w9, #0x1c0 // #448
c: 52800d8a mov w10, #0x6c // #108
* 10: f9403508 ldr x8, [x8, #104] <-- trapping instruction

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