[patch 5/5] fs: fix bdi writeback use after free 2

npiggin
2009-09-15T19:25:47Z

[-- Attachment #1: fs-bdiwb-rcu-fix-3.patch --]
[-- Type: text/plain, Size: 1165 bytes --]

work can be gone after wb_clear_pending, so load the sb from it first.

Signed-off-by: Nick Piggin <npiggin@suse.de>
---
fs/fs-writeback.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

Index: linux-2.6/fs/fs-writeback.c
===================================================================
--- linux-2.6.orig/fs/fs-writeback.c
+++ linux-2.6/fs/fs-writeback.c
@@ -783,6 +783,7 @@ long wb_do_writeback(struct bdi_writebac

while ((work = get_next_work_item(bdi, wb)) != NULL) {
enum writeback_sync_modes sync_mode;
+ struct super_block *sb;

nr_pages = work->nr_pages;

@@ -794,6 +795,8 @@ long wb_do_writeback(struct bdi_writebac
else
sync_mode = work->sync_mode;

+ sb = work->sb;
+
/*
* If this isn't a data integrity operation, just notify
* that we have seen this work and we are now starting it.
@@ -801,7 +804,7 @@ long wb_do_writeback(struct bdi_writebac
if (sync_mode == WB_SYNC_NONE)
wb_clear_pending(wb, work);

- wrote += wb_writeback(wb, nr_pages, work->sb, sync_mode, 0);
+ wrote += wb_writeback(wb, nr_pages, sb, sync_mode, 0);

/*
* This is a data integrity writeback, so only do the