diff options
| author | Jerome Marchand <jmarchan@redhat.com> | 2016-01-15 16:54:48 -0800 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-09-25 20:43:57 +0200 |
| commit | ba9244a6df14e6f4789ec967fcb24e21abbe1e8f (patch) | |
| tree | 6d8e59820c7020ace6be6b4042bf6261081bf2ee | |
| parent | 4eac2dc0b0ab3824362f260cde3e0e8980efb019 (diff) | |
zram: don't call idr_remove() from zram_remove()
The use of idr_remove() is forbidden in the callback functions of
idr_for_each(). It is therefore unsafe to call idr_remove in
zram_remove().
This patch moves the call to idr_remove() from zram_remove() to
hot_remove_store(). In the detroy_devices() path, idrs are removed by
idr_destroy(). This solves an use-after-free detected by KASan.
[akpm@linux-foundation.org: fix coding stype, per Sergey]
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org> [4.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index fba18b891..86e65b5ba 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1276,7 +1276,6 @@ static int zram_remove(struct zram *zram) pr_info("Removed device: %s\n", zram->disk->disk_name); - idr_remove(&zram_index_idr, zram->disk->first_minor); blk_cleanup_queue(zram->disk->queue); del_gendisk(zram->disk); put_disk(zram->disk); @@ -1318,10 +1317,12 @@ static ssize_t hot_remove_store(struct class *class, mutex_lock(&zram_index_mutex); zram = idr_find(&zram_index_idr, dev_id); - if (zram) + if (zram) { ret = zram_remove(zram); - else + idr_remove(&zram_index_idr, dev_id); + } else { ret = -ENODEV; + } mutex_unlock(&zram_index_mutex); return ret ? ret : count; |