Skip to content
Commit 13b215a9 authored by Lukas Czerner's avatar Lukas Czerner Committed by Theodore Ts'o
Browse files

ext4: don't use kfree() on rcu protected pointer sbi->s_qf_names



During ext4 mount api rework the commit e6e268cb ("ext4: move quota
configuration out of handle_mount_opt()") introduced a bug where we
would kfree(sbi->s_qf_names[i]) before assigning the new quota name in
ext4_apply_quota_options().

This is wrong because we're using kfree() on rcu prointer that could be
simultaneously accessed from ext4_show_quota_options() during remount.
Fix it by using rcu_replace_pointer() to replace the old qname with the
new one and then kfree_rcu() the old quota name.

Also use get_qf_name() instead of sbi->s_qf_names in strcmp() to silence
the sparse warning.

Fixes: e6e268cb ("ext4: move quota configuration out of handle_mount_opt()")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarLukas Czerner <lczerner@redhat.com>
Link: https://lore.kernel.org/r/20220104143518.134465-1-lczerner@redhat.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 173b6e38
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment