From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: "zhangyi (F)" <yi.zhang@huawei.com>
Cc: linux-ext4@vger.kernel.org, jack@suse.cz, adilger.kernel@dilger.ca
Subject: Re: [PATCH v5] ext4: fix potential use after free in system zone via remount with noblock_validity
Date: Sun, 25 Aug 2019 22:56:12 -0400 [thread overview]
Message-ID: <20190826025612.GB4918@mit.edu> (raw)
In-Reply-To: <20190825034000.GE5163@mit.edu>
I added a missing rcu_read_lock() to prevent a suspicious RCU
warning when CONFIG_PROVE_RCU is enabled:
diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index 003dc1dc2da3..f7bc914a74df 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -330,11 +330,13 @@ void ext4_release_system_zone(struct super_block *sb)
{
struct ext4_system_blocks *system_blks;
+ rcu_read_lock();
system_blks = rcu_dereference(EXT4_SB(sb)->system_blks);
rcu_assign_pointer(EXT4_SB(sb)->system_blks, NULL);
if (system_blks)
call_rcu(&system_blks->rcu, ext4_destroy_system_zone);
+ rcu_read_unlock();
}
int ext4_data_block_valid(struct ext4_sb_info *sbi, ext4_fsblk_t start_blk,
- Ted
next prev parent reply other threads:[~2019-08-26 2:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-15 11:47 [PATCH v5] ext4: fix potential use after free in system zone via remount with noblock_validity zhangyi (F)
2019-08-25 3:40 ` Theodore Y. Ts'o
2019-08-25 17:32 ` Eric Biggers
2019-08-26 2:56 ` Theodore Y. Ts'o [this message]
2019-08-26 8:31 ` zhangyi (F)
2019-08-26 15:03 ` Jan Kara
2019-08-27 9:20 ` zhangyi (F)
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