linux-ext4 - [PATCH] ext4: fix sleep inside spinlock issue aka #14739 [V3]

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [day] [month] [year] [list]

Message-id: <1260498987-6131-1-git-send-email-dmonakhov@openvz.org>
Date:	Fri, 11 Dec 2009 05:36:27 +0300
From:	Dmitry Monakhov <dmonakhov@...nvz.org>
To:	linux-ext4@...r.kernel.org
Cc:	jmaggard10@...il.com, Dmitry Monakhov <dmonakhov@...nvz.org>
Subject: [PATCH] ext4: fix sleep inside spinlock issue aka #14739 [V3]

unlock i_block_reservation_lock before vfs_dq_reserve_block().
this patch fix http://bugzilla.kernel.org/show_bug.cgi?id=14739

changes from V2:
 - fix meta_blocks leak.

Signed-off-by: Dmitry Monakhov <dmonakhov@...nvz.org>
---
 fs/ext4/inode.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 942e183..6fb7c73 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1851,6 +1851,7 @@ repeat:
 
 	md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
 	total = md_needed + nrblocks;
+	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 
 	/*
 	 * Make quota reservation here to prevent quota overflow
@@ -1858,12 +1859,10 @@ repeat:
 	 * time.
 	 */
 	if (vfs_dq_reserve_block(inode, total)) {
-		spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 		return -EDQUOT;
 	}
 
 	if (ext4_claim_free_blocks(sbi, total)) {
-		spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 		vfs_dq_release_reservation_block(inode, total);
 		if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
 			yield();
@@ -1871,10 +1870,11 @@ repeat:
 		}
 		return -ENOSPC;
 	}
+	spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
 	EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
-	EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
-
+	EXT4_I(inode)->i_reserved_meta_blocks += md_needed;
 	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
 	return 0;       /* success */
 }
 
-- 
1.6.0.4

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html