[LU-8774] copy_from_user() should not use MAX_STRING_SIZE

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.9.0
• Affects Version/s: Lustre 2.9.0
• Severity: 3
• Assignee: Jian Yu
• Reporter: Jian Yu

Description

The following codes are incorrect:

$ git grep "MAX_STRING_SIZE" | grep copy_from_user
lustre/ldlm/ldlm_resource.c:	if (copy_from_user(dummy, buffer, MAX_STRING_SIZE))
lustre/obdclass/lprocfs_status.c:	if (copy_from_user(dummy, buffer, MAX_STRING_SIZE))

We should only copy enough bytes to cover count passed in.

Comments

[Jian Yu]

Patch landed to master branch for Lustre 2.9.0.

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch http://review.whamcloud.com/23462/
Subject: LU-8774 lprocfs: not use MAX_STRING_SIZE in copy_from_user
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: a9ae88bbaca0770f28f3c88a4afed6b99403aec6

[Gerrit Updater]

Jian Yu ([e-mail]) uploaded a new patch: http://review.whamcloud.com/23462
Subject: LU-8774 lprocfs: not use MAX_STRING_SIZE in copy_from_user
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: f5c8d723829ca7289c15d9820f730213e2b7c4f4