linux-kernel - [PATCH] vfs: Fix NULL pointer dereference in fsync_buffers

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Tue, 4 Mar 2008 20:11:40 +0100
From:	Jan Kara <jack@...e.cz>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH] vfs: Fix NULL pointer dereference in fsync_buffers_list()

Fix NULL pointer dereference in fsync_buffers_list() introduced by recent fix
of races in private_list handling. Since bh->b_assoc_map has been cleared in
__remove_assoc_queue() we should really use original value stored in the
'mapping' variable.

Signed-off-by: Jan Kara <jack@...e.cz>
---

Hmm, somehow testing of private_list handling patch on ext2 never hit the code path with
the bug :(. UDF did... Please push to Linus. Thanks.

diff --git a/fs/buffer.c b/fs/buffer.c
index 897cd74..ddfdd2c 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -835,7 +835,7 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list)
 		smp_mb();
 		if (buffer_dirty(bh)) {
 			list_add(&bh->b_assoc_buffers,
-				 &bh->b_assoc_map->private_list);
+				 &mapping->private_list);
 			bh->b_assoc_map = mapping;
 		}
 		spin_unlock(lock);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/