Fix use-after-free by waiting for ongoing IO to complete before freeing
lbufs in lbmLogShutdown. Add a counter in struct jfs_log to keep track
of the number of in-flight IO operations and a wait queue to wait on for
the IO operations to complete.
Reported-by: [email protected]
Suggested-by: Hillf Danton <[email protected]>
Signed-off-by: Anirudh Rayabharam <[email protected]>
---
fs/jfs/jfs_logmgr.c | 17 ++++++++++++++---
fs/jfs/jfs_logmgr.h | 2 ++
2 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 9330eff210e0..82d20c4687aa 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -1815,6 +1815,8 @@ static int lbmLogInit(struct jfs_log * log)
*/
init_waitqueue_head(&log->free_wait);
+ init_waitqueue_head(&log->io_waitq);
+
log->lbuf_free = NULL;
for (i = 0; i < LOGPAGES;) {
@@ -1864,6 +1866,7 @@ static void lbmLogShutdown(struct jfs_log * log)
struct lbuf *lbuf;
jfs_info("lbmLogShutdown: log:0x%p", log);
+ wait_event(log->io_waitq, !atomic_read(&log->io_inflight));
lbuf = log->lbuf_free;
while (lbuf) {
@@ -1990,6 +1993,8 @@ static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
bio->bi_end_io = lbmIODone;
bio->bi_private = bp;
bio->bi_opf = REQ_OP_READ;
+
+ atomic_inc(&log->io_inflight);
/*check if journaling to disk has been disabled*/
if (log->no_integrity) {
bio->bi_iter.bi_size = 0;
@@ -2135,6 +2140,7 @@ static void lbmStartIO(struct lbuf * bp)
bio->bi_private = bp;
bio->bi_opf = REQ_OP_WRITE | REQ_SYNC;
+ atomic_inc(&log->io_inflight);
/* check if journaling to disk has been disabled */
if (log->no_integrity) {
bio->bi_iter.bi_size = 0;
@@ -2200,6 +2206,8 @@ static void lbmIODone(struct bio *bio)
bio_put(bio);
+ log = bp->l_log;
+
/*
* pagein completion
*/
@@ -2211,7 +2219,7 @@ static void lbmIODone(struct bio *bio)
/* wakeup I/O initiator */
LCACHE_WAKEUP(&bp->l_ioevent);
- return;
+ goto out;
}
/*
@@ -2230,13 +2238,12 @@ static void lbmIODone(struct bio *bio)
INCREMENT(lmStat.pagedone);
/* update committed lsn */
- log = bp->l_log;
log->clsn = (bp->l_pn << L2LOGPSIZE) + bp->l_ceor;
if (bp->l_flag & lbmDIRECT) {
LCACHE_WAKEUP(&bp->l_ioevent);
LCACHE_UNLOCK(flags);
- return;
+ goto out;
}
tail = log->wqueue;
@@ -2315,6 +2322,10 @@ static void lbmIODone(struct bio *bio)
LCACHE_UNLOCK(flags); /* unlock+enable */
}
+
+out:
+ if (atomic_dec_and_test(&log->io_inflight))
+ wake_up(&log->io_waitq);
}
int jfsIOWait(void *arg)
diff --git a/fs/jfs/jfs_logmgr.h b/fs/jfs/jfs_logmgr.h
index 805877ce5020..3e92fe251f28 100644
--- a/fs/jfs/jfs_logmgr.h
+++ b/fs/jfs/jfs_logmgr.h
@@ -400,6 +400,8 @@ struct jfs_log {
uuid_t uuid; /* 16: 128-bit uuid of log device */
int no_integrity; /* 3: flag to disable journaling to disk */
+ atomic_t io_inflight;
+ wait_queue_head_t io_waitq;
};
/*
--
2.26.2